Principles and Practice of Burn Care

Burn Wound Management
187
Fig. 14.43A: Meshing of graft being done by hand
Fig. 14.43B: Padgett’s roller skin graft mesher
the edges of the skin bridges adhere to the recipient
bed. This allows for greater total contact of graft to the
wound.
4. The raw areas seen within the mesh heals by the
epithelium migrating from the slit margins and this takes
only a few days as the raw areas within the mesh are
always less than 5 mm wide. It is well known that
epithelium spreads rapidly from the edge of the defect
for a distance of 5 mm and thereafter it spreads very
slowly.
5. Meshed graft can be easily placed in close proximity to
the wound surface in case of uneven or convoluted
surfaces.
6. It is easier to express out a hematoma or seroma from
under the surface of the graft without disrupting the
entire graft if it is meshed.
Fig. 14.44A: Zimmer’s skin graft mesher
Fig. 14.44B: Graft being meshed by passing it through the mesher
Fig. 14.44C: Meshed graft being applied on raw area

188
Principles and Practice of Burn Care
Disadvantages
The disadvantages of meshing are:
1. The checkered board pattern or cobblestone appearance
can be displeasing especially in aesthetically important
areas like face.
2. The secondary epithelium in the meshed area is not of
the same quality as the grafted skin and this is visible
for rest of life.
Application of Graft
Before the application of the graft to the wound bed it has
to be ensured that proper hemostasis is achieved especially
if the unhealthy granulation tissue on the wound bed has
been excised with a scalpel. Hemostasis is achieved by using
adrenaline saline soaked (1 in 2, 00,000) gauze pieces with
pressure dressing or by fibrin glue which is being used of
late (Tissel®).47,48 The graft is then spread over the wound
with the help of graft spreader or with the back of forceps
ensuring that the edges of the graft are properly spread out
as these have a tendency to roll over. This can then be held
in place with suture or surgical staples if areas are small or
with fibrin glue47,48 (Fig. 14.45). The graft can also be applied
on the raw areas without using the above and covered with
nonadherent gauze (Fig. 14.46).
In the past it was a routine to do an occlusive dressing
after any split skin grafting because it was considered that
pressure over a graft was essential for its ‘take’. However,
with time and experience with different techniques, it has
been clearly demonstrated that a graft can ‘take’
satisfactorily over granulating areas as long as it is not
Fig. 14.45: Fibrin glue applied as a spray for anchoring
graft to raw area
Fig. 14.46: Graft spread on wound as a sheet, edges rolled out
mechanically displaced or lifted off from its bed by
hematoma or pus formation and that occlusive dressings
are not a must. Areas like the anterior chest, abdomen and
back of trunk where constant motion during respiration
may displace the grafts by producing shearing between the
dressing and the wound bed are better treated by exposure
method after applying the graft. This is also true for the
neck (Figs 14.47A to C).
If dressings are used as in the limbs, it is imperative to
give an even gentle compression dressing with proper
immobilization of the extremity (Figs 14.48A and B). The
general principle is to immobilize a joint above and below
the grafted area to minimize limb movements and thus avoid
shearing forces. In case of mobile areas like axilla or neck,
stent dressing is advisable.
If the grafts are left without dressing, they should be
inspected daily for initial 4-5 days to check for any
displacement or any seroma or hematoma. However, if
meshed graft is used it is advisable to apply a layer of paraffin
gauze and a single layer of wet gauze till epithelialization of
the interstices has occurred. Otherwise the intervening raw
areas tend to dry up and epithelial migration is inhibited.
The same holds true for stamp grafts.
Skeletal traction can be given to the extremities to elevate
and immobilize the extremity following circumferential
grafting of the limb by exposure technique. Suturing of
graft edges is not favored in extensive raw areas as it can
result in hematoma and at times microabscesses at each
suture site resulting in graft loss. If adequate graft is available
it is preferred to overlap the adjacent graft edges slightly so

Burn Wound Management
189
as to avoid intervening raw areas. Since the intergraft raw
areas heal by epithelial proliferation from the graft margins
it results in hypertrophic scarring which is aesthetically ugly
and at times functionally poor.
Where homografts are available and donor area is
limited, alternate strips of autograft and homograft are
applied. In such cases as the homograft starts getting rejected
after 14 days, the epithelialization from the margins has
already covered quite a distance under the homograft. If
Fig. 14.47C: 2 months postoperative picture of same patient with
completely healed areas with no hypertrophy
Fig. 14.47B: Graft applied on the raw area over chest and released
neck contracture and left exposed
Fig. 14.47A: Granulating wound over chest and neck,
ready for grafting
Fig. 14.48B: Wound closure with split thickness skin autografts
Fig. 14.48A: Extensive granulating wounds over both lower limbs

190
Principles and Practice of Burn Care
homograft is not available and there are many small pieces
of graft as in ‘postage stamp’ grafts, they can all be spread
on paraffin gauze with raw surface upwards keeping a
distance of 1 cm between two pieces. The paraffin gauze is
then reversed and applied to the wound surface so that
grafts adhere to the bed. ‘Postage stamp’ autografts are
also useful on multiple small areas of granulation (Fig. 14.49).
The Meek grafting is another method of obtaining extensive
meshing to produce postage stamp grafts for coverage of
extensive areas, as has been described above (Figs 14.50A
to D).
Exposure technique is also preferred if the wound cultures
show gram-negative organisms as these organisms are
known to proliferate in the dark, moist and warm condition
provided by a dressing and will float the grafts off the bed
because of the volume of pus they produce. If these are
kept exposed the activity of these organisms is decreased
and chances of graft survival are better.
After the fourth day, usually the time by which the grafts
have adhered fairly well to the wound bed, change over to
treatment by dressings is advisable.
Delayed Application of Graft
At times in an anesthesized patient it may be difficult to
dress certain areas and there may be a risk of grafts getting
displaced during recovery from anesthesia as is seen in neck,
trunk and face and in heavy patients. In such cases, it is
advisable to store the grafts and apply them to the wounds
after a day when the patient is fully conscious and
cooperative. The grafts can be applied bedside without any
anasthesia. Delayed application of graft is preferred if slough
or granulation has been excised and oozing from the raw
area cannot be controlled.
Dressing Change
All postburn raw areas are potentially contaminated wounds.
Therefore, it is of utmost importance to change the first
dressing by 48-72 hours post grafting. This should be done
with full precautions not to move the grafts. They are only
dabbed with saline gauze to remove all the exudate and
express out any seromas through the mesh or by giving a
slit in the graft. A new dressing of the same type is reapplied.
If delayed beyond 72 hours, in the author’s experience,
bacterial autolysis of graft or the purulent collection under
the graft can lead to loss of significant areas of graft and
prolong the healing process.
The second dressing change can then be done at 5 days
post grafting and dried up graft overlapping the normal skin
can then be debrided and exposed dressing can be changed
to a closed dressing which will be less bulky. Thereafter,
the dressing can be changed as often as required till the
areas heal completely. Sutures or staples, if applied, can be
removed on the third dressing. Immobilization of joints can
be discontinued after 7 days, once the grafts have taken up
and some movements of joint can then be allowed during
dressing change to avoid stiffening of the joints. Proper
physiotherapy with full range of movements should be
resumed only after all dressings are removed and healing is
complete.
At times for one reason or the other, there can be small
areas of graft failure. If they are more than 1 cm wide,
patch grafting in a second stage may be required. However,
if they are less than 1 cm wide, even though they may be
long, trials at repeated grafting may fail. In these
circumstances the areas should be cleaned thoroughly and
dressed with some topical antibiotic over mesh gauze along
with some amount of topical steroid preparation. Though
steroids are known to inhibit epithelialization, they prevent
the formation of exuberant granulations, over which
epithelium anyway can not proliferate. The use of topical
steroids allows the hypertrophic granulations to settle and
the epithelium from the surrounding graft grows and spreads
over the remaining raw areas.
Blood Loss from Donor Areas
It is important to know about the blood loss while harvesting
graft since majority of the burn patients have borderline
Figs 14.49A and B: Intermingled skin grafting (Allograft and
autograft) leading to complete wound healing
A
B

Burn Wound Management
191
hemoglobin levels. It is believed that older patients bleed
less compared to younger patients who are well nourished
and have a good layer of subcutaneous fat. The back and
buttocks bleed more than other areas of the body. Bleeding
is more after harvesting thicker grafts than thinner grafts
(Figs 14.51A and B). However, on an average, while
harvesting split thickness skin graft, there is a loss of 23 ml
blood from 5 × 10 cm of donor area, approximately 1% of
total body surface area. This was studied by Robinson in
1949. However, it will vary according to the thickness of
graft taken.
Graft Survival
Graft survival has been studied in detail during the past
century. By definition, skin graft is a piece of skin which is
transferred from one place on the body to another after
severing its blood supply, lymphatic system and nerve supply.
So it is essentially skin transplantation and it derives its blood
supply and innervations from the recipient area.
Serum Imbibition
Immediately after a skin graft is applied to the wound bed,
the process of vascularization of the graft starts. Initially,
the graft depends on the serous exudates or plasma which
leaks out from the recipient venules, arterioles and capillaries
and fills up the space between the graft and host bed. This
plasma is absorbed by the graft and is the source of its
nourishment. This process was called ‘phase of serum
imbibition’ by Converse, Uhlschmid and Ballantyne49 and
originally called ‘Plasmatic circulation’ of graft by Alubscher
and Goldman.
Once the graft is lifted off the donor area, its vessels go
into spasm squeezing out old blood and serum. When it is
applied on the host bed, the cut ends of these vessels and
Figs 14.50A to D: (A) Meek machine for ‘Meek grafting’ with the cork plate and prefolded gauze (B).The graft is spread on the cork plate and
cut into small pieces by passing through the mesher. After the epidermal side of graft is sprayed with an adhesive, the graft is transferred to
a prefolded gauze and the cork plate is removed. Expansion is achieved by unfolding the gauze, first in one direction (C) and then in the other
direction (D) (Courtesy: Humeca Engineering group, Netherland)
A
B
C
D

192
Principles and Practice of Burn Care
the porous dermis starts absorbing the serum collected
between the graft and host bed passively. This makes the
graft edematous and its weight increases with anaerobic
metabolism which accumulates the waste products in the
graft till 48 hours until the venous drainage starts. In this
phase, there is growth of endothelial cells from the host
into the graft as well.
Graft Revascularization
There have been various theories regarding how the graft
gets revascularized. The earliest was the theory of
‘Abouchment’ given by Beat (quoted in50) in which he noted
microscopic anastomosis between host bed and graft. This
was supported by Thiersch (quoted in26) who termed the
process of anastomosis between cut ends of host vessels
and vessels of the graft as ‘inosculation’ in a full thickness
graft.
Twenty five years later, many researchers (quoted in50)
proposed that the original vasculature in the skin graft
degenerates and endothelial cells and capillary buds from
the host invade the graft by 9 hours and form a vascular
network and flow through the graft is established by the
4th postoperative day. These were confirmed by various
histochemical, injection and histologic studies.
Another theory proposed by Henry 51 stated that though
the original vasculature of the graft degenerates, the acellular
basal lamina persists and acts as a conduit for
endothelialization to start from the host capillary buds into
the skin graft. This is also seen within 48 hours.
Thus, all the theories are by and large proposing the
same explanation for the graft revascularization. To
summarize, the vascular connections establish within 24
hours after grafting allowing inflammatory cells to invade
the graft. By 4th postoperative day blood inflow through
the graft from the host bed is established. The graft now
appears pink and blanches on pressure. This flow continues
to increase till venous outflow from the graft back to the
host bed is also started and by 1 month after grafting, the
vascularization phase is completed.
The revascularization process is similar in both split
thickness and full thickness skin graft. However, split
thickness grafts survive longer without revascularization
than a full thickness graft because they contain fewer cellular
elements to be nourished. The serum imbibition has to take
place through a shorter distance through the dermis which
is thinner. In a full thickness graft, on the other hand, the
full thickness of the dermis acts as a barrier to the serum
diffusion and hence, it depends more on the supply through
the edges of the host bed with which it is contact. Thus, in
all granulating raw areas or areas with poor vascularity, a
thin split thickness graft survives better than a thicker graft
and should be used.
Once the process of revascularization is understood it
is easier to understand why a hematoma or seroma under a
graft inhibits its ‘take’ though they allow initial serum
imbibition. They prevent the vascular ingrowth from the
host bed into the graft which eventually dies out. Thus, it is
important to evacuate any hematoma or collection under
the graft before 72 hours by inspecting it on the first dressing
which is advisable by the 3rd day. After evacuating the
hematoma, the undersurface of the graft in that area where
it is lifted off the bed, also needs to be scraped or rubbed
Fig. 14.51A: Donor area of thin SSG—Bleeding points
are small but numerous
Fig. 14.51B: Donor area of thick SSG—Bleeding points are larger
but fewer

Burn Wound Management
193
with a gauze so that the tenuous lining of the proliferating
epithelium which forms on the undersurface of the graft
over the hematoma is removed. Otherwise it can inhibit the
graft ‘take’ once it is kept back on the host bed.
Graft Maturation
After the graft is vascularized it matures over a period of
time. An immature graft is soft, pink in color and blanches
on pressure and may be thick and shows scaling. The
process of maturation takes about 6-12 months. During
this phase of maturation both the wound and the graft appear
to undergo contraction. This process of graft contraction
is actually a manifestation of the wound bed contraction
mediated by the myofibroblasts. The myofibroblasts are
differentiated fibroblasts with features resembling the
smooth muscle cells, hence they contract the bed. This, in
turn, causes the graft to contract to the dimensions of the
underlying bed. This process is called ‘Secondary
Contraction’ of a skin graft.
Primary contraction of graft, on the other hand, is an
inherent property of every skin graft and occurs immediately
after the graft has been harvested. It is due to recoil of the
elastic fibers in the dermis. Therefore, primary contraction
is more in a full thickness graft as compared to a split
thickness skin graft because of greater amount of dermis
and greater amount of elastic fibers.
A full thickness graft has minimal secondary contraction
compared to a split thickness graft. The reason for this
appears to be the full thickness of dermis in these grafts
(FTG) which inhibits myofibroblasts differentiation. In a
split thickness graft, the lesser the amount of dermis, the
lesser is the inhibition of myofibroblasts differentiation,
therefore the bed tends to contract more. Thus, after
application of SSG to post burn raw area, splintage and
pressure is required for a long time postoperatively to avoid
the secondary contraction. Besides greater secondary
contraction in SSG, it tends to have lesser growth potential.
This is important in the pediatric age group. In children
with burns, treated with SSG, contracture formation is more
as the graft does not grow with age and with respect to the
rest of the body. An FTG on the other hand has a better
ability to grow with age but is rarely used in pediatric burn
wounds for reasons already stated.
In darker races, it has been observed that the graft is
susceptible to hyperpigmentation. Thus, exposure to sun
should be avoided for at least 1 year after grafting.
Reinnervation of Graft
The nerve fibers in the graft degenerate in 3 days after
transfer to the recipient site. The new nerve fibers invade
the graft from the periphery as well as the recipient bed at
40 days travelling along the empty Schwann sheaths or
along the blood vessels. At 2-3 months as these fibrils
increase in number they reach the end organs in the graft,
i.e. hair follicles, sweat glands and sensory end organs and
gradually the sensation returns in the graft. Pain is the first
sensation to return followed by touch, temperature and tactile
discrimination, although the sensation does not match that
of the normal skin. In fact, in the first year of post grafting,
the graft may be hypersensitive. The sensations are better
in full thickness (FTG) as compared to a split thickness
(SSG) skin graft.
Sweat glands present in the dermis of the skin graft
start functioning only after the reinnervation of the graft is
established. Therefore, there is no sweating in the graft for
2-3 months post grafting. Till such time, the graft remains
dry and scaly and needs to be protected by moisturizing
creams. Once the sweat glands are reinnervated, their
behavior is similar to that of the recipient bed and not the
donor site.
Hair growth is rarely seen in thin SSG because of damage
to majority of the hair follicles. But in a thick SSG and FTG,
hair growth resumes and resembles that of the donor area.
This is significant when FTG from scalp is used for eyebrow
reconstruction following burns.
Complications of Skin Grafting
1. The main complication of skin grafting is the failure of
graft to ‘take’. The various causes for graft failure are:
a. Infection: Infection is the most common reason for
graft failure especially with beta-hemolytic
Streptococcus. Therefore, it is imperative to have a
wound culture-sensitivity report prior to grafting.
b. Hematoma: Hematoma under the graft prevents the
graft from getting vascularized. Therefore, proper
hemostasis in the bed prior to application of graft
should be ensured. In case it cannot be achieved,
graft can be stored and applied after 1 or 2 days
when the bleeding stops.
c. Ineffective immobilization: Failure to immobilize the
grafted area is another important cause for failure of
graft ‘take’. Therefore, it is important to avoid
shearing between the graft and the wound bed and
for this proper measures as discussed above have to
be taken.

194
Principles and Practice of Burn Care
d. Poorly vascularized bed: It is not able to sustain a
graft and leads to graft failure.
2. Blister formation and breakdown in graft occurs in the
extremities especially weight bearing lower limbs in
which the increased hydrostatic pressure causes venous
congestion in graft. This is also seen as purple
discoloration of the graft.
3. Itching is a persistent problem of grafted patient. It is
due to drying of the graft.
4. Repeated scaling in the graft is seen because of absence/
diminished number of sweat and sebaceous glands in
the graft. Hence, they require lubrication for rest of the
life.
5. Contractures result from failure to splint and apply
pressure over the graft which allows secondary
contraction of the bed and graft. This process lasts for
1-2 years.
Postoperative Care of Graft
Once the wounds have completely healed, the grafts have
to be kept lubricated with some oil massage and require a
continuous pressure using pressure garments which prevent
inter-graft hypertrophy. In lower limbs, the pressure support
is essential for 3 to 6 months. This can be given by crepe
bandage or pressure garments. Apart from preventing
hypertrophy in grafts, they also prevent venous congestion
and breakdown in the graft. They have to be worn
throughout the day and night especially during ambulation.
At 10 days postoperatively, hanging of feet over the
side of bed can be allowed for short intervals of time followed
by elevation. Weight bearing in grafted lower limbs can be
started only after 2 weeks and gradually by 3 weeks walking
can be resumed but only with protection of a pressure
garment or crepe bandage.
The grafted area can be left exposed if there is no loss
by 10 days. By 14 days patient can be allowed to have a
bath. By 3 weeks the graft is usually strong enough to
withstand reasonable wear and tear.
Ideally, after the skin grafts are harvested they are
immediately applied to the raw areas. In case the wound
has been excised or debrided and hemostasis is not achieved
properly, it is a waste to apply the graft on a bleeding bed.
In these circumstances, the graft can be stored for a day or
two and applied to the raw area later in the ward. Sometimes,
an excess of graft may have been harvested and this excess
graft is also stored till such time that it may be used if there
is loss of some previously applied graft.
The most common and practical method of storing
autograft is in the refrigerator at 4°C. Chilling is known to
retard rate of metabolism and prolong survival. The grafts
are spread on paraffin gauze with raw surface upwards
and the paraffin gauze is then folded on itself and then further
wrapped in saline gauze. This is then placed in a sterile
bottle which is kept in the refrigerator at 4°C. Grafts can be
stored up to 3 weeks in this manner and thereafter discarded.
With increasing time interval, the tissue viability decreases.
Care should be taken not to freeze the graft as freezing at
temperatures below 0°C causes mechanical rupture of cells
and disruption of cytoplasmic contents. The reader is advised
to see the details of skin banking elsewhere in this book.
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2001;27:61-6.

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Principles and Practice of Burn Care
Surgical Excision of
Burn Wound and Skin Grafting
15
Pramod Kumar
Chapter
INTRODUCTION AND HISTORY
Ever since fire has been known to human beings, not only
it has been an undoubted boon but also a bane to some
extent. The treatment of oldest (59,000–48,000 BC) known
historic burn wounds with herbs and roots has been recorded
in cave paintings of Neanderthal man. Later in 1500 BC,
Egyptian Smith papyrus used salve of resin and honey for
treating burn wounds.1 Sushruta, the famous surgeon of
ancient India (800–600 BC) and regarded all over the world
as father of plastic surgery, in his book Sushruta Samhita2
(Section 1: Sutrasthana, Chapter 12: Agnikarma Vidhi
Adhyaya) has described the procedure of branding by fire
(Agnikarma vidhi), burns (Dagdha)—types and treatment,
suffocation due to smoke (Dumopahata lakshna) and sun
burn (Atapadi dagdhana).2
Although Jackson (1954) is regarded as the pioneer of
early burn wound excision and grafting, Janzekovic1 (1970)
showed that early return to work (about 1 week post burn)
is possible after tangential excision and split skin grafting
by day 3 to 5. In 1970, a brief article in Journal of Trauma
by Yugoslavian plastic surgeon, Zora Janzekovic, went
unnoticed. In 1974, Monafo advocated excision and grafting
for larger burns. In 1974, Burke used fascial excision for
large burns with a huge increase in survival and decrease in
hospital length of stay.1 Later, Janzekovic gained considerably
more attention when she reviewed her experience again as
the Evans lecturer for the American Burn Association in
1975.3 Until her observations were published, nearly all
excision and grafting procedures were limited to full
thickness burns and skin and subcutaneous tissues were
removed beneath the burn to the level of the investing fascia.
Due to disappointing results with excessive graft loss
following infection from adjacent non-excised area, she along
with many others abandoned early operation. Dr Janzekovic
knew that deep donor site could be over grafted with the
thinner autograft, thereby hastening the healing and
improving the appearance. Realizing that graft would survive
on viable dermis, she applied this technique to dermal burns
by progressive shaving off of thin layers of burnt dermis
until she reached a bed that appeared viable and she
immediately autografted it successfully. Between the years
1961 and 1974, Dr Janzekovic treated 2615 of 4370 burned
patients with this form of early tangential (or sequential)
excision and sheet autografting. Most of the burns were
small (less than 20% TBSA) but the hospital stay, pain and
need for reconstructive surgery reduced considerably and
lead to her opinion “Aesthetic disability” reduced
considerably.4 Though Tanner (1964) developed meshed
skin grafting technique, Alexander (1981) showed advantages
of using widely meshed autograft and its coverage with
cadaveric graft. Development of artificial skin, Integra TM
(bi-layered skin substitute made from collagen with plastic
cover) by Burke (1981) and development of tissue cultured
grown skin by Bell made a substantial improvement in the
management of larger burns using excisional surgery.1
Davies in 1990 reported that in India 22% of burns
patients died in the first 48 hours due to inappropriate or
inadequate fluid therapy, 36% by day 7 post burn due to
circulatory or respiratory complications and virtually all the
deaths during weeks 2, 3 and 4 after burns were due to

Surgical Excision of Burn Wound and Skin Grafting
197
overwhelming sepsis.5 Incidence of contractures and
hypertrophic scar is more if skin grafting is not done early
and wounds are allowed to granulate. Baxter6 documented
the possibility of minimizing wound infection by topical use
of 1% silver-sulfadiazine. Barret and Handerson7 (2003) in
their study concluded that burn wound excision significantly
reduces bacterial colonization. Patients who underwent
topical treatment and delayed burn wound excision exhibited
greater bacterial colonization and increased rates of infection.
Burke et al8 noted that time required for closure of the open
burn wounds using primary excision and skin grafting was
reduced to 11/2 time compared to topical therapy alone.
Modern advances and better understanding of burns
treatment, especially in burns resuscitation, infection control
and nutrition along with early excisional surgery and skin
grafting have led to significantly reduced overall morbidity
and to some extent burn wound sepsis and mortality.4
Uninfluenced by the survival statistics, excisional surgery
has become the treatment of choice for all deep dermal and
full thickness burns due to reduced cost of treatment, better
functional result, early rehabilitation with return to work
and a reduction in long term morbidity.
TYPES OF BURN WOUND EXCISION
The burn wound excision may be broadly classified into:
1. Primary excision: It is done within 3-7 days following
burns. It is actually a delayed primary excision because
it is done after the third day of burns for extensive burns.
This is further sub-classified into Tangential, Sequential
and Fascial excision, depending upon the technique used.
2. Secondary excision: This is basically a procedure for
preparing the wound bed for grafting by removing the
eschar. It is synonymous with surgical toilet or
debridement.
TYPES OF PRIMARY EXCISION
1. Tangential excision: It is used typically for deep dermal
burns. In this technique, the wound is excised with
Watson’s skin grafting knife till healthy viable dermis is
reached over which split skin graft is applied immediately.
2. Sequential excision: It is also used for deep burns in
which Watson’s skin grafting knife is used to sequentially
excise all necrotic tissue until viable tissue is encountered
which can be either viable deep dermis or viable fat or
fascia. This area is also immediately skin grafted. This
technique is most effective for mixed deep dermal and
full thickness burns in which sequential excision helps
in saving the viable dermis or fat which would otherwise
be sacrificed if the entire burned area were to be removed
with a surgical blade.
3. Suprafascial full thickness excision: It is indicated
for full thickness burn wounds. In this, full thickness
of burned skin with subcutaneous tissues is excised with
a surgical knife till the deep fascia. This can be
immediately grafted because fascia is a healthy bed for
graft ‘take’.
4. Subfascial excision: It involves excising till deep to the
deep fascia, thus reaching the muscles. In these cases,
the chances of graft ‘take’ are poorer compared to
suprafascial excision.
5. Escharectomy and delayed skin grafting: This was
practiced earlier for partial and full thickness burns in
which the nonviable eschar is excised with a skin grafting
knife till minimal bleeding bed is encountered. This bed
is, then, covered with a biological dressing and
reassessed after 48-72 hours to look for remaining dead
tissue which is again excised and dressed till healthy
granulation tissue appears. This is secondarily grafted.
This procedure is somewhere between primary excision
and secondary grafting following conservative
management of burn wounds as it takes 7-10 days for
the healthy granulation tissue to appear following excision
of dead tissue. This is, however, not practiced anymore.
It is suitable for cases where primary excision cannot
be done due to medical reasons or associated injuries.
ANATOMICAL AND PHYSIOLOGICAL
BASIS FOR EXCISION
The principle and type of excision can be explained by the
anatomy of skin and depth of burn. For excisional purposes,
the depth of burns is broadly classified into partial thickness
and full thickness burns. The partial thickness burns are
those which involve the epidermis and upper half of dermis
and they heal without intervention in 10-14 days. Full
thickness burns are those which involve the entire epidermis
and dermis and these do not heal on their own and require
surgical intervention. In between these two are deep dermal
burns which involve the epidermis and two thirds of dermis
and these heal in a long time with severe hypertrophic
scarring and contracture formation. So in these cases if
tangential excision is done it would not only improve
morbidity but even mortality is reduced dramatically. The

198
Principles and Practice of Burn Care
deep dermis is still viable, therefore it needs to be covered
with split skin graft following excision.
INDICATIONS
Early excision is especially appropriate for flame and dry
heat injuries, whereas a more conservative approach is
needed for scald injuries which are often associated with
less severe second degree burns that are likely to heal well
without excessive scarring. The results of a prospective
randomized study in a pediatric population showed that
scalded patients should be observed for approximately 14
days, after which the need for operative intervention can be
reassessed.9-13
Size of burn: It is a general agreement that small full
thickness, indeterminable and deep dermal burns can be
excised safely and grafted with good result (short hospital
stay, reduced morbidity, reduced burn wound pain and
sepsis, reduced nurses turn over in critical care area and
reduced scar related problems). Larger burns due to paucity
of skin donor area may require homograft, synthetic skin
substitutes or cultured epithelial autograft. In massive burns
(>60%TBSA) the problem of inadequate donor area can be
tackled by using widely expanded (meshed 1:4) autologous
split-thickness graft that can be overlaid with unexpanded
(with hand meshed) homologous (cadaver) split skin
graft.10,11,14,15
Burns of 30-40% BSA may be excised and covered with
autograft in two sessions at 10-14 days interval. The excision
of 15-20% BSA in one session is safe in healthy individuals,
although some surgeons set the limit even up to 40%.11 In
life threatening burns, one should aim at covering larger
areas (i.e. area easy to excise and easy to graft e.g. trunk)
rather than getting better functional result, (i.e. excision of
hand burn and finger burn that requires more time to cover
less area).16
Timing of excision relative to changes in the wound itself
is crucial to minimize risks: Timing for primary excision:
Tangential excision is usually done between 3rd and 5th day
following burns. The rationale for not doing it earlier is to
give adequate time for resuscitation especially in extensive
burns and to avoid unnecessary excision of deeper tissues
where perfusion is restored after resuscitation is completed.
Excision is not done after 5 days because there is a significant
bacterial colonization of wound by then which may inhibit
graft ‘take’. After 7 days, there is softening of the surface
of wound which makes excision technically difficult.
Colonization of the wound develops during the first week
and manipulation of the colonized or infected wound runs
an increasing risk of bacteremia. The reduced rates of wound
infection and sepsis in past three decades have been the
result of many factors, of which early excision has been
advocated as one of the major factors. Barret and Handerson7
(2003) have shown that burn wound excision significantly
reduces bacterial colonization. Patients undergoing topical
treatment and delayed burn wound excision exhibit greater
bacterial colonization and increased rates of infection. They
have also advised acute burn wound excision for all full
thickness burns. Desai18 et al (1990) have advocated that
near-total excision of large burn within first 24 hours reduces
blood requirement and morbidity without adversely altering
hemodynamic stability and increasing mortality risks. They
have shown that blood loss in large burn injuries (more
than 30% TBSA) was significantly decreased when surgical
excision was performed within the first 24 hours after injury
compared to those performed between the second and
sixteenth day after injury. Reduced blood loss was noticed
in second 24 hours after injury; however, this was not
significant compared to blood loss between post burn day
2 and 16. Blood loss in burns treated conservatively with
grafting on granulation tissue was also less when compared
to blood loss from excision during post burn day 2 through
16. Hence, the size of the planned excision must be
determined based on a clear understanding of increasing
risks of blood loss and bacteremia.
Early excision and grafting are not justifiable in conditions
like charred hand where paratenon is affected and flap
surgery is indicated. Excision and grafting should be avoided
in the presence of inhalation injury.
Criteria for Early Excision
The diagnosis of deep burn must be established (only areas
that do not blanch on applying pressure by finger tips are
excised), patient should have enough donor area and
patient’s condition should permit major operation. Inhalation
injury is often considered as contraindication for early
excision and grafting.
GENERAL PRINCIPLES FOR BURN WOUND
EXCISION AND GRAFTING
•
The patient must be hemodynamically stable before
considering excision.

Surgical Excision of Burn Wound and Skin Grafting
199
•
The potential for significant blood loss must be
recognized and adequate amount of blood and its
components, if indicated, must be available before starting
excision. Significant blood loss in a major burn should
be replaced with blood products.
•
Pulmonary problems require a plan of management in
the operating room. In post-operative period, mechanical
ventilation may be required.
•
Hypothermia must be prevented during surgery. All the
areas should not be exposed at a time. Operating room
temperature should be maintained between 80 and 85°F
and fluid warmer should be used. Patient’s body
temperature should be monitored.
•
The stress induced by anesthesia and surgery must be
limited to that which the patient can safely tolerate. Each
operative period should be limited to 2-3 hours.
As suggested by various authors4,19,20 the following
points should be considered when deciding to proceed with
operation:
1. Experienced surgeon is required for early excision.
Inadequate excision can lead to loss of graft placed over
it and add to the size of donor area thus created to the
extent of burn and may necessitate another operation.
2. Small burns that eventually heal and offer little threat to
life if allowed to heal over several weeks: In this group
patient selection should be such that if excised, operative
mortality remains non-existent.
3. Small burns that can be managed and taken care of by
the patient till healing at minimal cost without missing
work, may be treated conservatively.
4. Small deep burns can be treated on an out-patient basis
initially and then, excised electively and grafted on a day
surgery schedule.
5. Loss of income due to hand and feet burns can be
significantly minimized by early excision and skin
grafting.
6. Life threatening associated problems including trauma
must be well controlled so that operation can be done
with low morbidity and essentially no mortality. Herndon
et al20 have shown that the presence of pre-admission
shock and inhalation injury were early determinants of
mortality with secondary renal, pulmonary or
cardiovascular collapse being the later predictors of
mortality.
7. Large superficial burns with scattered small deep
components are best treated conservatively until the
shallow areas are healed.
8. To avoid problems of excessive wound related pain and
slough, excision and grafting may be one of the options.
Thompson et al,19 based on their study of effect of early
excision on major thermal injury, have indicated that
results with early radical excision and grafting of major
burn wounds (>50%) may prove to be equal to or better
than those achieved with conservative methods of topical
antimicrobial, delayed eschar separation and grafting.
9. Burns over sole and palm: Though early excision and
grafting was recommended as the preferred form of
treatment in patients with deep second degree and third
degree flame burns of dorsal hand21, it is generally agreed
that tangential excision and spilt skin graft is not advised
on palm and sole as there is a high possibility of damage
to the digital nerves and vessels. Singh and Prasanna22
in a study of five children with burns of feet have found
that the tangential excision and split skin grafting for
acute burns of feet helps in avoiding pain associated
with repeated dressing, reducing the need for
reconstructive procedures and hospital stay. It also
allows preserving sensate unburned skin and normal
growth of the foot.
10.Burns over scalp: Tangential excision of the scalp is not
practiced widely. Dickson et al23 in their study concluded
that it is preferable to manage scalp burns conservatively
and grafting as a secondary procedure. The earlier
reports of tangential excision of scalp and grafting
showing that it promotes faster healing, reduces chances
of hypertrophic scar and preserves hair growth have
not been confirmed by the study of Dickson et al.23
Furthermore, in their study, the major disadvantage of
this technique had been recurrent blistering, breakdown
and infection. True milia cyst formation was not
encountered in their study.
11. Burns of face: Wound excision and grafting is indicated
for face burns that do not heal within 3 weeks and that
the procedure yields results that permit the burn victims
to return to society and minimizes the time off work or
out of school.24
INVESTIGATIONS
1. Hematological: Hemoglobin, total and differential
leucocytes count, platelet counts, Preoperative
coagulation profile (if indicated)
2. Routine urine examination (sugar, protein and
microscopic examination)
3. Bacterial culture: Wound swab, and if indicated blood
culture

200
Principles and Practice of Burn Care
4. Serum electrolytes
5. Serum protein level (albumin, globulin),
Immunoglobulin level (IgG, IgM)
6. Renal function tests
7. Myoglobin in urine (if urine is smoky or tea-like
coloration), Investigation for rhabdomyolysis: creatine
kinase (CK), aldolase, lactate dehydrogenase (LDH),
serum glutamic-pyruvic transaminase (SGPT), and
other enzymes.
8. In electric burns: ECG, creatine kinase (CK; also known
as phosphocreatine kinase or creatine phosphokinase-
CPK), and CK-MB.
9. Arterial blood gas analysis, X-ray chest, Bronchoscopy
(if indicated)
10. Investigations to rule out other organ dysfunction (if
indicated)
11. Investigations for co-morbid condition and pre-existing
illnesses.
TANGENTIAL EXCISION
Tangential excision (Figs 15.1A to 15.5D) is indicated
for deep dermal wounds. In tangential excision burnt dermis
is excised with modified Humby’s skin grafting knife (e.g.,
Watson’s)/hand held dermatome or power driven
dermatome. Since excision is done tangent to the wound
and often multiple thin slices of the tissue are excised till
viable bleeding tissue is reached, the method of excision is
called tangential excision.
Anesthesia during excision and grafting: During excision
following anesthesia related problems are encountered:
•
Setting up of intravenous line: Due to burn wounds, it is
difficult to get IV line at usual sites and to fix it by
adhesive tape. Very often jugular line is started during
anesthesia. Central line is started as the last option.
Protecting the line during surgery and changing patient’s
position under anesthesia may be difficult.
•
Patient monitoring: Continuous monitoring of ECG, pulse
and blood pressure may be difficult in burns patients as
compared to other patients. This may be due to the
pattern of burn, extensive nature of the burn and unusual
position of the patient on the operation table. By using a
precordial stethoscope or use of esophageal stethoscope
one can continuously monitor heart beat. Continuous
monitoring of blood pressure may be done by starting
an arterial line as the last option. It may be difficult to
Fig. 15.1C: Postoperative view of same patient following tangential
excision and grafting of deep dermal burn of right upper extremity—
Extensor aspect
Fig. 15.1D: Postoperative view—Flexor aspect
Fig. 15.1A: Preoperative view: Deep dermal burn of right upper
extremity—Extensor aspect
Fig. 15.1B: Preoperative view: Deep dermal burn of right upper
extremity—Flexor aspect

Surgical Excision of Burn Wound and Skin Grafting
201
Fig. 15.2A: Deep second degree burn of right upper extremity
Fig. 15.2B: Result after tangential excision and split skin grafting
place standard ECG electrodes. Therefore, ECG leads
are placed at a position that is convenient to both the
anesthesiologist and the burn surgeon. Many a times,
the site of the sphygmomanometer cuff and finger probe
for monitoring oxygen saturation has to be changed from
one place to other to enable surgeon to complete the
operation.
•
Difficult intubation: Intubation may be difficult due to
upper airway edema. Once intubated, fixation by
adhesive tape may not be possible in facial burns. In
this situation the endotracheal tube is tied around the
neck with a bandage and the bandage is fixed on the
tube at an appropriate site with an adhesive tape.
•
Muscle relaxant: In acute burns (like immobilized
patients, or those patients who had repeated sepsis) the
use of Suxamethonium (succinylcholine) is known to
be potentially dangerous due to exaggerated
hyperkalemia.
•
Sudden blood loss from multiple sites during excision
may produce serious problems during anesthesia.
Excision may have to be stopped for some time if deemed
necessary by anesthesiologist. Large quantities of fluid
may need to be transfused in a short duration.
•
Hypothermia: Uncovered burnt areas, excised areas and
donor areas result in quick loss of heat. Keeping the
areas covered that are not being operated, using fluid
warmer for fluids being transfused, monitoring patients
temperature, controlling operating room temperature,
using warm saline mops and limiting the duration of
surgery reduces the problem of hypothermia.
•
Hypovolemia: Sudden loss of large volumes during
surgery may cause oliguria, anuria and finally renal
failure. Urinary output measurement at the beginning of
surgery, hourly during the surgery and in postoperative
period helps in minimizing the problems.
•
Postoperative ventilatory support: Maintenance of oxygen
saturation may be difficult due to inadequate chest wall
movement or chest complications making it necessary
to ventilate these patients in postoperative period.
Technique of tangential excision: First of all, the area of
deep dermal burn to be excised is mapped and marked (Figs
15.3A, 15.4A and 15.5A). For tangential excision with
Watson’s modification of Humby’s skin grafting knife, the
knife is set to take thick split skin graft. Saline is used to
keep the area wet and help in easy movement of knife.
Slices of burned tissue are excised till viable tissue with
brisk bleeding is encountered (Figs 15.3B and C, 15.4B and
15.5B). Viable dermis appears shiny white in color with
multiple bleeding points. Small deeper (3rd degree) burnt
areas in the deep dermal burn wound may be excised
tangentially till viable bright yellow fat is exposed and
nonviable brown fat is completely excised. ‘Take’ of skin
graft over the fat is relatively poorer as compared to that on
viable dermis. To avoid sudden loss of a large volume of
blood, one smaller area is excised and perfect hemostasis is
achieved before starting excision over another area. Topical
application of adrenaline solution for 5-10 minutes and then
use of slow water jet over excised area to localize bleeding
points for bipolar cauterization are commonly used to achieve
hemostasis. Exposed viable dermis and other tissues are
covered immediately by adrenaline solution soaked sponges
to avoid its desiccation followed by cover with split thickness
skin graft (Figs 15. 3E and F, 15.4C and 15.5C).
Smaller areas of burn surrounded by unburnt skin are
difficult to excise by large size knife. Hence, smaller knives
like Silver or Goulian-type Weck knife is used. The author

202
Principles and Practice of Burn Care
Fig. 15.3A: Areas of deep dermal burns mapped in forearm
prior to excision
Fig. 15.3B: Watson’s knife used to excise dead skin
layers only in the mapped out areas
Fig. 15.3C: Healthy reticular dermis layer reached
Fig. 15.3D: Fibrin sealant applied locally for hemostasis
Fig. 15.3E: Split skin graft applied after bleeding is controlled
Fig. 15.3F: Second postoperative dressing after 8 days showing
graft fully taken up and area healed

Surgical Excision of Burn Wound and Skin Grafting
203
Fig. 15.4A: Deep dermal burns of dorsum of hand
Fig. 15.4B: Tangential excision being done with Watson’s knife
Fig. 15.4C: Graft applied after excision on dorsum of hand
Fig. 15.4D: Postoperative picture showing complete
take of graft on healthy bed
Fig. 15.5A: Deep dermal burn over thigh – Area marked
Fig. 15.5B: Dead layer tangentially excised
Fig. 15.5C: Hemostasis being achieved with fibrin sealant
Fig. 15.5D: 2 weeks postoperative picture showing completely
healed area

204
Principles and Practice of Burn Care
uses pinch technique, in which the skin adjacent to the
wound is pinched to lift burnt area from the unburnt area as
a skin fold and the excision is performed by Watson’s skin
grafting knife.
For harvesting graft from uneven areas like chest wall
and scalp, it is advisable to inject saline in subcutaneous
tissues.
Blood Loss during Excision
Operative blood loss during excision can be calculated by
following formulae:
a. By measurement of pre- and postoperative hematocrit
value:
Blood loss in ml =
(Preoperative RBCV) + (T × RBCV)
– (Postoperative RBCV)
Postoperative hematocrit × 0.01
Where:
RBCV= red blood cell volume
Preoperative RBCV (ml) = Body weight (kg) × 80 (ml/
Kg) × [preoperative hematocrit (%) + 0.01]
Postoperative RBCV (ml) = Body weight (kg) × 80 (ml/
Kg) × [postoperative hematocrit (%) +0.01]
T × RBCV = Total ml. whole blood administered during
surgery × 0.03
Desai et al18 have shown that
i.
Average amount of blood loss for more than 30%
TBSA burns when excised in the first 24 hours after
injury was 0.41 ± 0.06 ml/cm2
ii. Average amount of blood loss for more than 30%
TBSA burns when excised between 2 and 16 days
after injury was 0.75 ± 0.04 ml/cm2
iii. Average amount of blood loss for more than 30%
TBSA burns when excised more than 16 days after
injury was 0.49 ± 0.07 ml/cm2
b. By measurement of pre- and postoperative hemoglobin
value: This formula implies that decrease in hemoglobin
is due to intraoperative blood loss along with
hemodilution because of large volume of intraoperative
crystalloid transfusion.
Blood loss in ml =
EBV × [(preoperative Hb – postoperative Hb)/ average
Hb] + Tx
Where:
EBV= estimated blood volume (70 ml/ Kg of body
weight)
Preoperative Hb = preoperative hemoglobin in g/L
Postoperative Hb = hemoglobin in g/L at 24 hours
postoperatively
Average Hb = the mean of preoperative and postoperative
hemoglobin in g/L
Tx = Total intraoperative and 24-hours postoperative
transfusion volume received in ml.
Using this formula, Cartotto et al25 calculated the blood
loss (mean ± SD) to be 211± 166 ml per % TBSA excised.
Blood loss can be minimized by application of topical
epinephrine with or without thrombin to excised wounds
and/or donor sites; the subcutaneous infiltration of
vasoconstrictors such as epinephrine, phenylephrine or
vasopressin at donor and/or excision sites; the administration
of systemic vasopressin; controlled intraoperative
hypotension; performing excision with laser; and use of
limb tourniquets.25 Locally reacting fibrin sealants like Tissel®
are now available for use over such excised areas for control
of bleeding (Figs 15.3D and 15.5D) However, there is no
uniform, complete and consistent approach to reduce
intraoperative blood loss. From time to time, concerns have
also been raised over assessing viability of recipient bed
when tourniquet is used or subeschar epinephrine is used
to reduce blood loss. This is because such methods interfere
with bleeding from the viable tissues left after excision.
To reduce blood loss from donor area and burnt areas
(to be excised) where tourniquet application is not possible,
epinephrine solution 1:5,00,000 may be infiltrated
subcutaneously until they become firm (i.e. tumescent).
After harvesting graft, epinephrine saline solution
(1:2,00,000) soaked gauze may be used topically.
To reduce blood loss during excision from the burnt
areas over extremities, tourniquet is inflated 100 mm Hg
above systolic pressure. After excision is complete topical
epinephrine solution may be used for 10 minutes before
release of the tourniquet. After release of the tourniquet, the
limb is again wrapped in epinephrine solution soaked gauze
for another 5 minutes.
For assessment of viability of the tissues after excision
under tourniquet and epinephrine solution, the appearance
of the tissues left is observed: the dermis must be pearly
white, with no hemorrhagic staining; minor vessels on the
wound surface must be patent; the fat must be pale yellow,
firm, and moist (dry or golden brown fat is unhealthy); and
the excised wound rapidly becomes hyperemic, even under
tourniquet control. In particular, shortly after what appears
to be adequate excision, the white dermis and pale yellow
fat appear to develop hemorrhagic staining. Although this

Surgical Excision of Burn Wound and Skin Grafting
205
usually represents re-perfusion, it can easily be confused
with the staining that characterizes thermally injured tissue.
Thus, there may be a tendency to unnecessarily re-excise
the area. Hence, the level of excision is most easily determined
with the initial passes of the debriding blade and should not
be altered thereafter unless there is convincing evidence of
inadequate excision (e.g., tissue fails to re-perfuse, remains
dry or contains thrombosed vessels on the wound
surface).25
The order of excision: In cases of extensive burns, the
first aim of excision should be towards coverage of the
area (large and easily excisable areas e.g. trunk) rather than
towards functional recovery (excision of small and difficult
to excise areas like hand).
Advantages
As compared to en bloc excision, tangential excision
produces less contour problems and better cosmetic result.
This technique results in better texture of grafted skin and
greater sensitivity.
Complications
The immediate complication is failure of graft ‘take’ which
may be due to inadequate excision, infection, hematoma
and lack of proper immobilization.
Problems
1. Cyst formation, probably as a result of blockade of the
ducts of adnexal glands.
2. Overhanging skin graft margin.
3. Pinhead dark spots from inspissated secretions which
disappears after meticulous cleaning.
4. Epithelial bridging showing hair follicle at the
undersurface of the epithelium.16
Limitations: Paucity of graft donor area in extensive burn is
taken care by use of allograft, homograft or synthetic skin
temporarily till cultured auto-keratinocytes are available.
Intermingled xeno/homograft and autograft may be used in
absence of keratinocyte culture facilities26.
EN BLOC EXCISION
Excision En Bloc (Figs 15.6A to 15.7D) is indicated for
third degree burns and involves removing the burnt skin
and all underlying burnt tissues (that may include fat, deep
fascia and burnt muscle) en bloc till healthy bleeding tissue.
This can be done with scalpel, electric cautery or laser
scalpel.16 When excision is done up to the level of deep
fascia (sometimes including muscle fascia), it is called fascial
excision (Figs 15.6A and B).
In fascial excision, the skin, subcutaneous tissue and
deep fascia is incised by knife and scissors. Traction is
applied over the tissue to be excised and lifted from the
plane deep to the deep fascia and burnt tissue is excised en
block. If muscle is involved, it is debrided thoroughly. During
en bloc excision (Figs 15.7A to D) fewer and larger vessels
are encountered. To reduce blood loss, these vessels should
be divided after ligating or cautery application. To ensure
good graft ‘take’, perfect hemostasis is achieved before
covering the area with skin graft.
Advantages
Blood vessels are easily identified at the level of deep fascia
and hence, tackled easily to reduce blood loss. Graft ‘take’
is usually better than that on fat exposed after excision of
burn involving full thickness of dermis.
Problems
1. Excision of subcutaneous tissues alters body contours
(aesthetically poor result), results in poor texture of grafted
skin and poor sensitivity. Hence, whenever possible, fat
should be preserved over face, hands, dorsum of foot
and areas around the joints. In females one should attempt
to preserve as much mammary parenchyma as possible.
Fig. 15.6A: Third degree burn of both lower extremities
Fig. 15.6B: Result after fascial excision and split skin grafting

206
Principles and Practice of Burn Care
2. While excising over tendoachillies and tendons over
dorsum of hand and foot, the importance of staying in
correct plane can not be overemphasized in order to
avoid exposure of bare tendons.
Whatever technique is used, there is no substitute for
experience of the surgeon and good facilities in a center
where routine excisional surgery is performed.4
Immunological benefits of wound excision and closure:
Wound excision and closure causes decrease of
proinflammatory mediators, decreased endotoxemia and
restoration of contact hypersensitivity. It has been shown
that burn injury inhibits cytotoxic T lymphocyte (CTL)
function (which is involved in antigen recognition, processing
and elimination) in a size dependent manner and total wound
excision significantly improves both CTL function and
survival after injury. Therefore, it has been suggested that
early excision may help to restore host immunocompetence
and may decrease the infectious complications of thermal
injury.27
Wound Debridement: In cases where burn excision and
split skin grafting is not done due to medical or other
reason(s), excision of dead tissue i.e. wound debridement
(Escharectomy, Slough excision) is done, if needed,
repeatedly at 48-72 hours intervals followed by repeated
dressings till healthy granulation tissue (fit for split skin
grafting) appears.
POSTOPERATIVE MANAGEMENT
In the immediate postoperative period, hemoglobin, PCV,
serum electrolytes level is checked to assess blood loss and
appropriate action is taken as per report. Hourly vital signs
and urine output is measured and intravenous fluid is
administered as per requirement. Antibiotics, as per culture
and sensitivity report, analgesic and supportive treatment is
instituted. Depending on gut function, oral feeding is started
after 6 hours or later.
Depending on wound condition, dressing is done on
day 3-5 and then, on alternate days. Donor area heals in 10-
14 days. Physiotherapy is started after 7 days. Any splint, if
required, is delivered at the time of discharge or during
follow up visits.
SUMMARY
•
Wound excision and skin grafting is an established
method of treatment for deep dermal, indeterminable
depth and deep burns.
•
Technique-wise, excisional surgery is classified as
tangential or en bloc excision. Based on the time of
Fig. 15.7A: Third degree burn of chest and right upper extremity
Fig. 15.7B: Excised tissue
Fig. 15.7C: Viable tissue following en bloc excision
Fig. 15.7D: Result after en bloc excision of burnt tissue
including superficial muscle

Surgical Excision of Burn Wound and Skin Grafting
207
excision, it may be classified as acute (within 24 hours),
early (within 3-5 days) or delayed (within 6-16 days)
excision.
•
Excisional surgery has led to reduced overall morbidity
significantly and to some extent, burn wound sepsis
and mortality. It has also led to reduced cost of treatment,
reduced wound related pain, better functional result, early
rehabilitation and reduced long term morbidity with
reduced time away from work.
•
As compared to en bloc excision, tangential excision
produces less contour problems and better cosmetic
result. This technique results in better texture of grafted
skin and greater sensitivity.
•
Experience of the surgeon and facilities available at the
center where excision is done is important. Less than
20% TBSA excision is safe. If treated with excision and
grafting 20-40% TBSA burn patients appear to have
fewer infectious wound complications and a shorter
hospital stay.
•
A significant increase in blood loss should be expected
with wound excisions after 5 to 6 days as infection and
inflammation of the viable tissue below eschar might
increase its vascularity. Clotting abnormalities at this stage
can also be a major problem.
•
Chances of sepsis increase if excision is delayed by more
than 5 days.
•
By early excision and grafting, full functional recovery
may be achieved within 2 weeks, whereas in the
conventional method, de-sloughing alone requires 3
weeks and the shortest possible time for full healing is
therefore about 5 weeks.
•
Scarring (hypertrophy, contractures) is less if wound is
closed early and there is reduction in the need for
reconstructive procedures.
REFERENCES
1. Cinat ME, Smith MM. Acute Burn Management. In: Sood R, Achauer
BM (Eds), Burns Surgery Reconstruction and Rehabilitation.
Philadelphia: Elsevier Inc, 2006:50-76.
2. Murthy KRS (Translator in English language). Illustrates Sushruta
samhita (Text, English Translation, Notes, Appendices and Index),
second edition. Varanasi: Choukhansha Orientalia, 2004:70-77.
3. Janzekovic Z. The burn wound from the surgical point of view. J
Trauma 1975;15:42-61.
4. Heimbach DM. Early Burn Excision and grafting. Surg. Clin. of
North Am. 1987;67:93-107.
5. Davies JWL. The problems of burns in India. Burns 1990; (Suppl
1):S4-24.
6. Baxter CR. Topical use of 1% silver sulphadiazine. In: Polk HC Jr.
Stone HH (Eds), Contemporary Burn Management. Boston: Little
Brown & Co.1971;217
7. Barret JP, Handerson DN. Effect of burn wound excision on bacterial
colonization and invasion. Plast Reconstr Surg. 2003;111:744-49.
8. Burke JR, Bondoc CC,Quinby WC. Primary burn excision and
immediate grafting. A method of shortening illness. J Trauma
1974;14:389.
9. Desai MH, Rutan RL, Herndon DN. Conservative treatment of
scald burns is superior to early excision. J Burn Care Rehab
1991;12:482-4.
10. Nguyen TT, Giplin DA, Meyer NA, Herndon DN. Current Treatment
of severely Burned Patients. Ann Surg 1996; 223:14-25.
11. Prassanna M, Singh K, Kumar P. Early tangential excision and skin
grafting as a routine method of burn wound management: an
experience from a developing country. Burns 1994;20:446-50.
12. Kumar P, Chirayil PT, Chittoria R. Then and Now- Burns in Manipal
(letter). Burns 2000; 26:66-7.
13. Kumar P, Chirayil PT, Chittoria R. Ten year’s epidemiological
study of pediatric burn in Manipal, India. Burns 2000; 26:261-4.
14. Herndon DN, Barrow RE, Rutan RL, Rutan TC, Desai MH, Abstan
S. A Comparison of Conservative Versus Early Excision: Therapies
in severely burned patients. Ann. Surg 1989; 209:547-53.
15. Alexender JW, McMillan BF, Law E, et al. Treatment of Burn with
widely meshed skin autograft and meshed skin allograft overlay. J
Trauma 1981;21:433-8.
16. Klasen HJ. Early excision and grafting. In: Settle JAD (Ed),
Principles and Practice of Burns Management. NewYork: Churchill
Livingstone, 1996;275-287.
17. Herndon DN, Barrow RE, Rutan RL, Rutan TC, Desai MH, Abston
S. A comparison between conservative versus early excision;
Therapies in severely burned patients. Ann Surg1989;209:547-53.
18. Desai MH, Herndon DN, Broemeling L, Barrow RE, Nichols RJ Jr,
Rutan RL. Early burn wound excision significantly reduces blood
loss. Ann Surg 1990;211:753-62.
19. Thomson P, Herndon DN, Abston S. Effect of early excision on
patients with major thermal injury. J. Trauma 1987;27:205-7.
20. Herndon DN, Gore D, Cole M, Desai MH, Linares H, Abston S,
Rutan T, Osten TV, Barrow RE. Determinants of Mortality in
Pediatric Burns with Greater than 70% Full-thickness Total Body
Surface Area thermal Injury Treated by Early Total Excision and
grafting. J Trauma 1987;27:208-12.
21. Shin HS, Lee JW, Jang YC. Clinical Experiences in Management of
the Extensive Flame Burns Dorsal Hand by Early Excision and
Graft. J Korean Soc Plast Reconstr Surg. 2000;27:234-9. Korean.
22. Singh K, Prasanna M. Tangential excision and skin grafting for ash
burns of the foot in children: a preliminary report. J. of Trauma
1995;39:560-2.
23. Dickson WA, Sharpe DT, Roberts A. Tangential Excision of Scalp
Burns: experience from the Bradford fire disaster. Burns
1988;14:151-5.
24. Cole JK, Engrav LH, Heimbach DM, Gibran NS, Costa BA,
Nakamura DY, Moore ML, Blayney CB, Hoover CL. Early Excision
and Grafting of Face and Neck Burns in Patients over 20 Years.
Plast Reconstr Surg. 2002; 109:1266-73.
25. Cartotto R, Musgrave MA, Beveridge M, Fish J, Gomez M.
Minimizing Blood Loss in Burn Surgery. The Journal of Trauma,
Injury, Infection, and Critical Care 2000; 49:1034-9.
26. Chih-chun Y, Tsi-siang S. Resurfacing acute extensive deep wound.
In: Jackson IT, Sommerland BC. Recent Advances in Plastic surgery.
Edinburgh: Churchill Living Stone, 1985;155-167.
27. Hultman CS, Cairns BN, deserres S, Frelinger JA, Meyer AA. Early,
complete burn wound excision restores cytotoxic T lymphocyte
function. Surgery 1995;118; 421-30.

208
Principles and Practice of Burn Care
Anesthesia for the Thermally Injured
16
PK Verma
Chapter
INTRODUCTION
The first written documentation describing the treatment
of thermally injured dates back to almost four millennia.1
However, it is only in the last 60 years that any significant
improvements in morbidity and survival have occurred. In
the past, up to 20% deaths were due to the effects of
hypovolemia, contributing to early mortality following burns.
Currently, most deaths occur several weeks after injury
and are due to multiple organ failure, often in association
with sepsis. More people are surviving major burns than
ever before and the percentage of total body surface area
(% TBSA) burn that is lethal to half the victims is now in
the region of 70% in the population up to the age of 45
years.2 Improved survival rates are due to the adoption of
early tangential excision of the burn wound, techniques of
infection control, technological advances in cardiac,
respiratory and renal support in the intensive care unit and
an overall greater aggressive approach to the management
of this injury by intensivists.
The anesthetist is an essential member of the burn
management team possessing both the skills as well as the
knowledge required for the treatment of the burn injured at
all stages. The need for specialized burn anesthesia is obvious
as these patients undergo many operations, sometimes
within a short period of time. They need multiple blood
transfusions following extensive blood loss during early
excisional surgery. A burn victim needs an integrated
approach by the burn team to achieve minimal morbidity
and mortality.
PATHOPHYSIOLOGY
It is important to understand the early pathophysiological
changes that occur with thermal injury as successful ongoing
management relies on the response to resuscitation. Thermal
injury produces many of the physiological changes3 that
are seen in any major trauma but are more profound and
longer lasting.
Cardiovascular Changes
After a burn injury, especially over 20% total body surface
area (TBSA) burn, there is a loss of capillary integrity, in
both normal and burned tissues, resulting in a loss of plasma
volume into the interstitial space and the burn wound. During
this resuscitation phase, lasting 72 hours, aggressive fluid
replacement is essential to maintain the perfusion of the
vital organs. In addition, adequate intravenous analgesia is
administered not only for the comfort of the patient but
also because the pain alters the vital signs that are so useful
to monitor resuscitation.
The fluid shifts in the early post burn period decrease
the cardiac output independent of the status of intravascular
volume. Reduced cardiac contractility results from
circulating humoral factors, reduced responsiveness and
decreased coronary blood flow. The magnitude of cardiac
impairment is larger in the older patients. Systemic vascular
resistance also increases, coincident with the decrease in
cardiac output.
After successful resuscitation in the first 24-48 hours
after a burn, the myriad of inflammatory mediators and
cytokines released change the cardiovascular response into

Anesthesia for the Thermally Injured
209
the classical systemic inflammatory response syndrome
(SIRS). This syndrome is manifested by an increased
cardiac output and reduced systemic vascular resistance
and reflects a marked increase in the metabolic rate. The
consequences of this are important. These systemic
inflammatory response syndrome manifestations are
identical to those seen in sepsis and care must be taken to
avoid antibiotic use in the absence of other evidence of
systemic infection. In addition, this syndrome is the prime
cause of hypermetabolism seen in a severely burnt patient.
Respiratory System Changes
Upper airway injuries result from inhalation of superheated
air or steam and toxic compounds found in smoke. Brief
exposure of the epiglottis or larynx to either dry air at 300oC
or steam at 100oC leads to massive edema and rapid airway
obstruction. In children, this may result in macroglossia,
epiglottitis and laryngotracheal bronchitis. Even patients with
a mild upper airway injury are at risk for development of
progressive airway obstruction as tissue edema develops.
The clinical signs (Table 16.1) that should alert the clinician
to the possibility of upper airway burns are facial burns,
singed nasal vibrissae, bronchorrhea and sooty sputum (Fig.
16.1). If severe, patient may appear dyspneic, use accessory
muscles of respiration and sit upright. Hoarseness and
dysphagia are common. Flow-volume curves and
nasopharyngoscopy may aid the initial diagnosis of upper
airway burns and are particularly useful in assessing trends
in airway impairment. If an inhalational injury is suspected,
it is vital that the airway be secured at the earliest possible
time. Intubation is mandatory in a large burn with an
inhalational injury as resuscitation may cause massive
swelling and jeopardize the patency of the airway (Fig. 16.2).
In fact, any delay may make a subsequent attempt at
intubation physically impossible due to loss of identifiable
landmarks as a result of severe edema of all the structures
above the larynx. It may be wise to avoid performing a
tracheostomy on these patients as this procedure is
associated with a high mortality4 (Fig. 16.3).
The oropharynx and upper airway are efficient heat
exchangers. Therefore, thermal burns to the lower airway
are rare unless steam or chemicals have been inhaled. The
clinical signs described for upper airway injury are also
applicable to lower airway injuries. In addition, the patient
may give a history of being confined in a smoke-filled, closed
space and may exhibit raised levels of carboxy-hemoglobin.
If the thorax is burned, chest wall compliance may be
decreased by edema, by the formation of an inelastic eschar
and possibly by the application of tight bandages. Lung
compliance and functional residual capacity may also be
reduced. Minute ventilation and the alveolar/arterial gradient
for oxygen increase, mainly because of edema and reduced
Table 16.1: Clues to inhalational injury
•
Exposure in a closed-space
•
Loss of consciousness
•
Nasal, oral or facial burns
•
Singed nasal vibrissae
•
Carbonaceous sputum
•
Hoarseness or stridor
•
Upper airway changes on bronchoscopy
•
Flow–volume curves
•
Chest radiograph showing pulmonary edema
Hypermetabolic state manifests clinically as a persistent tachycardia
(despite adequate resuscitation), hyperpnea and marked muscle wasting.
Fig. 16.1: Patient with face burns along with inhalation injury
Fig. 16.2: Patient with inhalation injury requiring intubation for
mechanical ventilation

210
Principles and Practice of Burn Care
cardiac output. Hypoxia coupled with increased work of
breathing may exhaust the patient. These considerations
reinforce the necessity for early tracheal intubation, high
concentrations of oxygen and controlled ventilation.
Metabolic Changes
The burn injury results in a massive catecholamine output.
The outcome is a hypermetabolic state characterized by
protein catabolism, urea genesis, liploysis and
gluconeogenesis. In patients with burns of more than 50%
of the total body surface area, the basal metabolic rate may
be doubled.
The loss of skin and the increased metabolic rate impaire
the thermoregulation of the patient who responds by
increasing his core temperature to 38.5oC. This persistent
pyrexia may mask the early signs of sepsis which is the
most common cause of death once the patient has reached
a burns unit. A high index of clinical suspicion, supported
by hematological and bacteriological surveillance, is essential
and aggressive antibiotic therapy must be initiated early.
Ambient temperature has an important effect on the
metabolic rate in burn patients. A study of patients with a
mean burn size of 44% TBSA showed that patients at
thermoneutral ambient temperature (28-32oC) had metabolic
rates 1.5 times those of unburned controls. However, when
ambient temperature was decreased to 22-28oC, the
metabolic rate increased in proportion to burn size. Thus,
ambient temperature less than thermoneutral range should
be avoided, whether in the burn unit or in the operating
room, to minimize further increase in metabolic rate.
The increase in metabolic rate has implications for
nutritional support in the post burn period. Early feeding
decreases muscle catabolism and may reduce bacterial
translocation through the intestinal mucosa. Adequate pain
control, alleviation of anxiety, a thermoneutral environment
and an aggressive treatment of infection are all important
steps in limiting catecholamine secretions and thus,
hypermetabolism which diverts calories from the healing
tissues.
Immunologic Changes
Sepsis and multiple-organ failure are a major cause of death
among burned patients. Large areas of dead tissues are easily
colonized with bacteria and the burned patient is less able to
fight infection as a result of impaired white blood cell
function and reduced levels of fibronectin and
gammaglobulins.
ANESTHETIC MANAGEMENT
Convalescence from a thermal injury can be divided into
three phases. The anesthetic requirements during the three
phases are different and will be discussed separately. First
is the resuscitation phase, which starts at the time the patient
sustains the burn. This phase deals with maintenance of the
airway, acute fluid replacement and cardiovascular
stabilization and analgesia (Table 16.2). All anesthetists must
be familiar with the acute resuscitation of victims of major
burns. Hemodynamic stability and adequate urine output
should be established within 72 hours after injury and the
resuscitation phase is now complete. This is followed by
the hypermetabolic stabilization phase (when skin grafts
are used to cover the defects). This phase may last up to 90
days or more. Finally, the third phase, i.e. the reconstructive
phase deals with the restoration of form and function of
damaged tissues and the release of contractures.
Resuscitation Phase
The role of an anesthesiologist in the acute resuscitation of
a severely burnt patient varies from institution to institution.
Fig. 16.3: Patient with severe inhalation injury requiring
tracheostomy for ventilation
Table 16.2: Problems encountered by the anesthetist
in the resuscitation phase
•
Airway management
•
Cardiovascular stabilization
•
Fluid replacement
•
Analgesia
•
Life-saving surgical interventions.

Anesthesia for the Thermally Injured
211
The special skills of the anesthetist in airway management,
fluid management and percutaneous, intravenous and arterial
catheterization may be required. The detailed discussion of
the management during this phase is beyond the scope of
this chapter and has been discussed elsewhere.
Anesthesia during resuscitation phase should be provided
only for life-saving procedures. Common surgical problems
which may require anesthesia are usually injuries associated
with burns, for example, amputation of non-viable limb,
exploratory laparotomy or thoracotomy for penetrating
injuries, etc. All else should be postponed till the patient has
been resuscitated and stabilized. In the presence of injuries
like fractures, abdominal or thoracic trauma which are
commonly associated with blood loss, blood replacement
may be required in addition to resuscitation fluids. Ketamine
may be the safest agent for anesthesia during this period
and may be used in combination with a non-depolarizing
neuromuscular blocking agent (NMBA) if relaxation is
required. Suxamethonium may be used to facilitate intubation
from the time of injury to 48 hours after injury but should
be carefully avoided thereafter. Increased oxygen demand,
tachycardia and decreased compliance may make
mechanical ventilation (MV) mandatory both, preoperatively
and postoperatively. Adequate analgesia must be provided
in the perioperative period and great care must be taken to
ensure continued adequate resuscitation during anesthesia.
Hypermetabolic Stabilization Phase
Some of the commonly performed operations during this
phase include primary excision and skin grafting, dressings
and debridement.
The pathophysiological state of the patient presenting
for surgery and anesthesia varies depending on the percentage
of TBSA burnt, location of burns, age of the patient, time
elapsed since initial injury and adequacy of the treatment
received in the resuscitation phase5 (Table 16.3). Blood loss
due to increased wound vascularity, hypothermia and plasma
potassium levels are the predominant considerations during
surgery on the burn patients in this phase.
Preoperative Assessment and Preparation
(Table 16.4)
Successful anesthesia for excision and grafting of a burn
patient requires planning. Because burn patients often
undergo many operative procedures, it is important for the
anesthetist to establish good rapport with the patient and
explain all movements and procedures in advance, especially
if they may be painful.
A brief history should be obtained, either from the patient
or from the progress notes. The cause of the burn should
be ascertained. Electrical burns may cause myocardial
damage. Chemical burns are associated with a high
incidence of renal or hepatic damage. Exposure to toxic
fumes or concurrent inhalational injury may interfere with
respiratory function. Past medical history, allergies, recent
medications, previous surgery and previous anesthetics
should be reviewed.
Physical examination may be limited by dressings,
dyskinesia or pain. The extent of the burn and other injures
Table 16.3: Factors modifying the pathophysiological state of the
patient
•
% TBSA burnt
•
Location of burns
•
Age of the patient
•
Time elapsed since initial injury
•
Adequacy of the treatment received in the resuscitation phase
Table 16.4: Considerations in preoperative evaluation/during
preoperative visit of the burned patient
•
Reassure the patient; establish rapport; explain the procedure in
advance.
•
Obtain history of the patient
–
Ascertain the cause of burn (chemical, electrical, inhalational
etc.)
–
Review any past history of relevance.
•
Perform physical examination
–
Record the extent of burn and other injuries
–
Assess current IV access and whether the current site needs a
change
–
Assess the airway and predict if a difficult intubation is likely
–
Assess for adequacy of resuscitation (mental status, skin color,
capillary refill, hematocrit, oxygen saturation, urine output)
and correct any deficiency.
–
Evaluate cardiovascular system (ECG, BP, CVP, Pulmonary
artery catheterization, if indicated)
–
Ascertain the respiratory status (X-ray chest, ABG)
–
Look for evidence of any coagulation abnormality (Hb/
Hematocrit, electrolytes, coagulation profile)
–
Any evidence of acute renal failure (blood urea, serum
creatinine, serum electrolytes, urine output, urine osmolality).
•
Interact with the burn surgeon (nature and extent of excision,
amount of blood loss, operative time)
•
Arrange for the estimated blood loss
•
Premedication
–
Provide adequate analgesia
–
Brief period of fasting
•
Take a decision about the monitoring and care to be provided
during transport.
•
Consider antithrombotic prophylaxis.
•
Record any additional point(s) of relevance.

212
Principles and Practice of Burn Care
should be ascertained from the recorded notes. The
respiratory and cardiovascular system should be examined
as in any other assessment. The sites of possible venous
access should be evaluated as these may be limited and
difficult to find. The assessment of the airway and
predicting, if a difficult airway is likely, is important in these
patients at this stage. Finally, adequacy of resuscitation is
observed/checked. Simple parameters like assessment of
mental status, skin color, capillary refill, hematocrit values,
oxygen saturation and urine output should be employed fully.
Noninvasive blood pressure measurement and
electrocardiographic (ECG) monitoring should be a routine,
but unusual sites may be required for the cuff and electrodes.
Placement of a sterile cuff over burned areas is acceptable
or an unsterile cuff may be placed over a thin occlusive
dressing. Invasive arterial and central venous pressure
monitoring may be helpful, particularly for patients with
extensive burns or an inhalational injury. However, these
carry significant risk of infection.
Of all the parameters available, urine output is probably
the most useful. If resuscitation is adequate, the urine output
should be at least 0.5 ml/kg body weight/hour and the
osmolarity of the urine in the range of 600 to 1000 mosm/l.
In the presence of myoglobinuria, mannitol may be given to
promote diuresis. In these patients the urine output is no
longer a reliable guide to the adequacy of resuscitation. If
resuscitation is inadequate, this is the time to take corrective
measures.
Respiratory status of the patient should be assessed
carefully during the preoperative assessment and strategy
to deal with the findings planned accordingly. A patient with
burns around the airway (e.g. singed nasal hair) should be
intubated as early as possible. Direct inhalational/thermal
injury and fluid resuscitation may make delayed intubation
more difficult secondary to upper airway edema, as
discussed earlier. Physiologic derangements due to injury
to lower airways may include pulmonary edema and acute
respiratory distress syndrome (ARDS). Additionally, burn
patients can be severely hypermetabolic, with corresponding
increased carbon dioxide production. These patients may
have high peak inspiratory pressures (PIPs) and high minute
ventilation requirements. High level of positive end-expiratory
pressure (PEEP) may be helpful in these patients. Other
possible effects of severe burns include: decreased lung
and chest wall compliance, decreased functional residual
capacity (FRC), increased alveolar-arterial oxygen gradient,
increased carboxy hemoglobinuria and increased
methemoglobinuria. Chest radiograph and arterial blood gases
(ABG) should be asked for to evaluate the progress of the
patient’s condition. Septicemia and chest infections are
generally associated with respiratory failure and are
indications for controlled mechanical ventilation.
The variations of urea and electrolytes in blood should
be corrected preoperatively. An element of renal failure
associated with inadequate resuscitation may be present.
The blood sugar is usually elevated and may cause an osmotic
diuresis with a concomitant loss of electrolytes.
Coagulopathies may result directly from the burn injury,
especially in the 2nd week post burn, as well as from rapid
replacement of blood loss during operative procedure and
should be monitored closely. Coagulation profile, hemogram,
hematocrit and electrolyte reports should be analyzed to
monitor the condition of the patient. The hematocrit, if all
else is normal, indicates the level of hydration.
Preoperative anemia is, in part, dilutional in the early
days, but levels below 8 gm/dl should be corrected before
surgery. The attention to anticipated amount of blood loss
should be given at this visit. Postoperative oozing into
dressings can be considerable and this loss should also be
taken into account when ordering blood to maintain the
hemoglobin concentration above 10 gm/dl. It is important
(during this preoperative visit) for the surgeon and
anesthetist to decide collectively, about the nature and extent
of the excision, the amount of blood loss anticipated and
the anticipated operative time in view of the patient’s
condition. The endpoints for surgical excision in large burns
are: (i) Operative time of 2-3 hours; (ii) core temperature of
35oC; or (iii) blood loss of 10 units of packed red blood
cells. The violation of any of these parameters invites
coagulopathy and increasing problems with hemostasis and
vital signs stability.
Preoperative fasting guidelines have been modified in
burn patients for several reasons. Achieving adequate caloric
intake in patients with major burns is difficult and nutritional
support is frequently supplemented with nasogastric tube
feedings. Thus, minimizing the fasting period before
operation is beneficial. It is advisable not to discontinue
enteral feeding before operation in patients who are already
intubated with cuffed endotracheal tubes; in non-intubated
patients, feeding should be stopped 2 hours prior to surgery.6
This improves preoperative nutrition without apparently
increasing the risk of aspiration.
Premedication should be ordered; an opioid analgesic
like morphine or pethidine along with promethazine should
be used. An anti-sialagogue such as atropine or
glycopyrrolate may also be included in the premedication.

Anesthesia for the Thermally Injured
213
The effect of the premedicant analgesic should be noted
because these patients may be unduly sensitive or apparently
resistant to analgesics. If all that is needed is an anxiolytic,
then a benzodiazepine such as lorazepam may be used. The
property of anti-recall, which is profound with lorazepam,
is very beneficial in a patient who undergoes many
procedures. Ketamine continues to have a role in
premedication for children via the oral or rectal routes.
Antithrombotic prophylaxis should be considered,
balancing the hypercoagulable state of the major burn with
the risk of disseminated intravascular coagulation (DIC)
and the potential for deep vein thrombosis in any non-
ambulatory patient against the risk of hematoma formation
under skin grafts or skin substitute.
Preoperative visit is also the time to plan the ways to
transport the patient (depending on the condition) from ward
to the operating room. The patient may be brought to the
operating room on the ward bed as any movement to and
from a transport trolley causes unnecessary pain. For patients
with severe ARDS, transportation may pose formidable
challenges with regard to ventilation. Cardiopulmonary
monitoring must be continued during transport; the
ventilation system used in transport must be capable of
delivering high minute volumes, PEEP and inspiratory
pressures. These requirements may not be satisfied by
standard bag-valve systems and may require a high-quality
transport monitor.
The following conditions may be considered as
contraindications7 for surgery:
•
Inadequate resuscitation;
•
Abnormal electrolytes;
•
Respiratory or metabolic acidosis;
•
Abnormal clotting studies;
•
Incipient septicemia;
•
Unexplained rapid temperature changes;
•
Changed consciousness level;
•
Instability in respiratory or cardiovascular parameters.
Intraoperative Period
Whilst there is no single technique that may be regarded as
ideal, a number of general principles apply (Table 16.5).
Skin-grafting or free-tissue transfer must not be jeopardized
by poor perfusion during or after anesthesia. The use of
hypotensive techniques, smooth balanced anesthesia and
excellent analgesia with good fluid/blood replacement
contribute to a successful outcome and avoid anesthesia
Table 16.5: Anesthetic consideration for excision and grafting of
major burns
•
Premedication
–
Provide adequate analgesia
–
Brief period of fasting
•
Vascular access
–
Establish large-bore IV access
–
Consider invasive monitoring
•
Induction
–
Volume resuscitated: Propofol /Thiopentone
–
Volume depleted: Ketamine
•
Securing the airway
–
Consider alternatives to direct laryngoscopy
–
Consider awake intubation
•
Ventilation
–
Ventilation requirement, due to:
- Hypermetabolism
- Parenteral alimentation
–
Smoke inhalation / circumferential burns / ARDS may
necessitate ICU-type ventilator
•
Fluid and blood
–
Blood loss can be extensive
–
Check coagulation profile
–
N-saline / Ringer lactate @ 8-10 ml/kg/hour
–
Keep urine output 0.5-1 ml/kg/hour
–
Continue parenteral nutrition
•
Temperature regulation
–
Warm all fluids and keep operation theater warm
–
Humidify gases
–
Warming blanket/reflective head cover
•
Selection of anesthetic agent
–
Include opioids with all techniques
–
Catecholamine (endogenous and exogenous) levels are
increased: choose/use compatible inhalational agents
•
Muscle relaxants
–
Avoid succinylcholine
–
Resistance to NMBAs (non-depolarizing muscle relaxant )
•
Recovery/Postoperative state
–
Opioid requirements are large
–
Keep the patient warm
–
Check coagulation profile
–
Continue cardiopulmonary monitoring
–
Oxygen administration
–
Consider initiating enteral nutrition as early as possible
Adopted and modified from: MacLennan N, Heimbach DM and Cullen BF.
Anesthesia for major thermal injury. Anaesthesiology 1998; 89: 749-70
being blamed for poor surgical outcome. Regional techniques
are rarely feasible, given the multiple surgical sites for
harvesting and skin grafting. Laryngeal mask airways
(LMAs), in general, are not recommended for major burns,
given the potential for significant fluid resuscitation and
subsequent airway edema, as well as the frequent
repositioning of patient intraoperatively. LMAs, however,
are invaluable for shorter procedures, avoiding repetitive

214
Principles and Practice of Burn Care
laryngeal instrumentation and for their ability to maintain
the difficult airway while deepening the anesthetic or as an
aid to intubation with or without the fiberoptic
bronchoscope8( Fig. 16.4).
Induction of Anesthesia
The patient should be brought to the induction room on the
ward bed (if facilities exist), as any movement to and from
a transport trolley causes unnecessary pain. Induction of
anesthesia can be performed on the bed and the patient
transferred to the operating table once profound analgesia
has been obtained. Non-invasive monitoring should be placed
in site prior to induction of anesthesia (Fig. 16.5). A second
anesthetist is helpful to assist in induction. A surgeon should
be available in the induction room. He may be called upon
to perform a cut-down on a vein if percutaneous venous
access is not possible. Securing venous access is a pre-
requisite to burn excision and grafting procedures. This
may be established the night before surgery to ensure
adequate hydration. For most cases, a minimum of two
large-bore peripheral intravenous (IV) lines or one peripheral
and one central line should be used. These may be inserted
under local anesthesia with xylocaine and used for induction.
Insertion of large-bore cannulae can be performed under
general anesthesia. The positioning of both IV access and
monitoring should be discussed with the surgeon with
respect to the operative site.
Pre-oxygenation is advisable, because of the high
metabolic rate, tachycardia and increased oxygen needs. If
the trachea is assessed as being easy to intubate and patient is
adequately volume-resuscitated, fentanyl at 3-5 mg/kg body
weight may be given by slow IV injection. This may be
followed with an induction dose of propofol (1-2 mg/kg).9
This technique allows for rapid recovery and minimizes
postoperative cognitive disturbances. Alternatively,
thiopentone (3-5 mg/kg) may also be used. Xylocaine
(1-1.5 mg/kg) may be given prior to intubation to depress
the cardiac response to intubation and enhance the potency
of fentanyl. If the patient is intravascularly volume-depleted,
ketamine (1-3 mg/kg) is recommended. Patients with
extensive burns (>30% TBSA) develop a decreased
sensitivity to non-depolarizing neuromuscular blocking agent
(NMBAs); therefore, 1.5 times the usual intubating dose of
NMBAs is recommended: vecuronium (1.5 mg/kg),
pancuronium (0.15 mg/kg), or rocuronium (1.5 mg/kg). If
rapid sequence induction is indicated, high dose rocuronium
(2 mg/kg) can be used. Succinylcholine is contraindicated
during this phase (i.e. when injury is >48 hours old) because
of potentially lethal efflux of potassium ions from muscle.
This abnormal response probably occurs because the entire
muscle membrane, rather, than just the myoneural junction
becomes a receptor.
In case, a difficult intubation is anticipated, alternative
plans should be sought for. As mentioned earlier,
tracheostomy is not recommended, being associated with
higher mortality. Most injuries leading to difficult intubation
will have burns around the face and neck which are likely
to be infected. If a tracheostomy is performed, it may lead
to septicemia, mediastinitis or chest infection, ultimately
causing the demise of the patient. Facial burns, with a raw
Fig. 16.5: Anesthesia work station with attached noninvasive
monitors
Fig. 16.4: Fiberoptic set

Anesthesia for the Thermally Injured
215
area on the face, may make placing a face mask difficult on
the face. A sterile Gamgee pad, with a hole in the area of
nose and oral aperture, may be used to cover the raw area
and the face mask can be kept on the pad. The other
methods of intubation which can be considered include
inhalational induction followed by blind nasal intubation,
awake fiberoptic intubation (Figs 16.6A to C), crico-
thyroidotomy with jet ventilation, cricothyroid puncture and
retrograde cannulation or percutaneous tracheostomy. The
LMA has proved its worth and is an acceptable alternative
method to try for shorter procedures (Fig. 16.7). Securing
the endotracheal tube (ETT) can be difficult in the presence
of facial burns (Fig. 16.8). Alternatives to taping the ETT
include suturing the tube to the lip10 or using a
circumferential tie around the patient’s head.
Maintenance of Anesthesia
Controlled ventilation, facilitated with muscle relaxants, is
the method of choice for all but the shortest procedures,
i.e. dressing changes. This technique reduces oxygen
consumption and makes it possible to increase the minute
volume to ensure that normal carbon dioxide levels are
maintained in these highly catabolic patients. Physiologic
derangements of the respiratory system (poor gaseous
exchange and a low compliance) and a hypermetabolic state
may require high inspiratory pressures, PEEP, and other
ventilatory adjuncts to maintain oxygenation. Depending on
equipment availability, an ICU ventilator may be necessary.
The effect of positive pressure ventilation, PEEP and
hypovolemia may summate to have a deleterious effect on
the cardiac output and renal function and must be avoided
by ensuring adequate intravascular volume and if required,
by the use of inotropic agents.
Inhalational agents may be used to provide balanced
anesthesia. Intraoperatively, burn surgeons commonly use
epinephrine soaked sponges to decrease blood loss.
Systemic absorption of epinephrine causes tachycardia and
increases the probability of dysrhythmias; therefore, it is
better to avoid halothane or desflurane. Isoflurane and
sevoflurane are acceptable. The prolonged or repeated use
of nitrous oxide may decrease erythropoesis by inhibition
of vitamin B12. This can be overcome by hydroxycobalamine
injections.
Circumferential burns may require the patient to be
moved during the procedure. An armoured tracheal tube
and a lightweight co-axial breathing system, such as the
Bain system may be preferred. The cornea should be
Fig. 16.6A: A patient with chronic post burn raw area with
contracture of neck with difficult airway
Fig. 16.6B: Fiberoptic bronchoscopy through intubating LMA being
tried for the same patient through oral route because of pinched
nostrils
Fig. 16.6C: Same patient successfully intubated orally

216
Principles and Practice of Burn Care
blood pressure cuff may be applied to a lower limb when
both upper limbs are to be operated upon. The blood pressure
cuff may be rotated from one extremity to another to
accommodate the surgery or an arterial catheter may be
inserted. Surface electrodes may not adhere even after
tincture of Benzoin has been applied, in which case
percutaneous needle electrode may be required.
Transesophageal electrodes may be the method of choice
even though they are expensive. The pulse rate can usually
be measured manually, by the arterial waveform or by ECG
tracing. The pulse oximeter is a useful monitor which
indicates hemoglobin saturation as well as the pulse rate. A
suitable pulse for the sensor may be difficult to find.
Alternative sites include the earlobe and nasal septum. An
esophageal stethoscope can be used to monitor both heart
and breath sounds. Capillary refilling can be easily observed
and the patient’s color noted. These clinical observations
may be all that is available in certain patients and conditions.
Because of increased metabolic rate and carbon dioxide
production, increased alveolar ventilation may be required.
Arterial Blood Gas analysis (ABG) must, therefore, be
assessed early and frequently throughout the anesthetic
procedure. Constant monitoring of expired carbon dioxide
is very helpful during intraoperative management. However,
one must be cognizant of the possibility of significant
differences between arterial and expired carbon dioxide
values as a result of shunting and dead space ventilation in
patients with severe pulmonary injury.
All patients with major burns have a urinary Foley
catheter in place. Adequate fluid replacement ensures a good
urine output but a decreased output is a late sign of inadequate
replacement. Temperature control is a major problem and
heat loss can be enormous. Both core and peripheral
temperatures must be monitored. Heat loss is minimized by
warming all fluid, especially those used to prepare skin for
surgery. The thermoneutral temperature for these patients
is between 31oC and 33oC. This can be extremely
uncomfortable for the working staff. A compromise of
between 27oC and 30oC is usually made. Areas not being
operated upon must be covered; overhead heaters and heating
blankets should be used, especially on children; and simply
covering the head may make a noticeable difference. A falling
peripheral temperature may be due to an inadequate plasma
volume if the core temperature is remaining static.
The most important feature of the intraoperative course
is monitoring and replacing patient’s blood loss. The
expected blood loss may be 100-200 ml/%BSA excised and
Fig. 16.7: LMA ( Laryngeal mask airway)
Fig. 16.8: Endotracheal tube
protected with eye ointment and pressure points should be
padded. Facial burns may make eye closure difficult, and a
temporary tarsorraphy may be required after prior discussion
with the patient.
Adequate analgesia should be given during the
intraoperative period and should continue in the postoperative
state. It is humane to complete the dressing and place the
patient on the ward bed before terminating anesthesia.
Inadequate post-operative analgesia may make the patient
restless; this in turn may provoke bleeding under the skin
grafts (and their subsequent loss) or alternatively,
displacement of the grafts. If large volume resuscitation
has occurred intraoperatively, there is a possibility of
clinically significant airway edema; use caution before
extubating a patent airway.
Monitoring
Monitoring methods which are taken for granted in non-
burn patients may be difficult in the burned patients. The

Anesthesia for the Thermally Injured
217
grafted. Therefore, one must be familiar with the surgical
approach to burn excision. During a tangential excision, a
patient might loose three to five times more blood than during
excision down to fascia. Intraoperative tourniquet use on
burned extremities reduces overall blood loss and also
decreases the rate of loss, making intraoperative hypovolemia
less likely. Some centers use postoperative compression
dressing after excision and grafting to reduce blood loss.
Epinephrine (500 μg/l in normal saline) injected
subcutaneously in both donor and excision sites are also
used to reduce blood loss during excision and grafting
procedures. Although high levels of catecholamines in the
blood have been measured with this technique, complications
such as dysrhythmias are uncommon. After burn injury,
cardiovascular responses to catecholmines are attenuated
because of a reduced affinity of the β-adrenergic receptors
for ligands and decreased second messenger production.
Blood loss is also quite dependent on the expertise of the
surgical team. Hypotensive anesthesia has also been
advocated as a means to decrease blood loss. Exact
estimation of the blood loss is difficult because of bleeding
into dressings, drops, sponges and packs, and on to the
floor. Other indicators of circulating blood volume, such as
urine output, central venous pressure, arterial pressure and
shape of the arterial waveform, whenever possible, must
be closely monitored. Blood loss should be replaced
adequately. For patients without contraindications to
hemodilution (e.g. coronary artery disease, anemia), it is
often better to delay packed red blood cells transfusion until
major blood loss is complete. If sudden decrease in blood
pressure occurs during very rapid transfusion of blood (>150
ml/min), using calcium to counteract the chelating effect
of citrate is considered. However, one should be cautious
to avoid over transfusion especially in a small child or in an
elderly. As the surgical site is superficial, there is not much
third space loss.
Total parenteral nutrition should be continued throughout
the procedure in order to avoid large changes in blood sugar
levels which may occur when parenteral nutrition is
constantly interrupted by surgical procedures. Difficulties
are encountered due to the effects of stress response on
the uptake and hormonal control of fluids. Intermittent hourly
monitoring of blood sugar under anesthesia can help to
prevent excessive hyper or hypoglycemia. In children, the
rate of infusion of glucose solutions must be adjusted to
maintain a normal blood glucose level throughout the
operative and recovery periods.
Postoperative Care
Excellent analgesia during the operation is imperative and
relative overdose must not be reversed with antagonists. It
is better to support ventilation for a few hours than to reverse
analgesia and subject the patient to the subsequent pain or
discomfort that ensues. If the patient wakes up complaining
of pain, an opioid should be titrated intravenously to obtain
the required effect.
Normal cardiopulmonary monitoring should be continued
during transportation and in the postoperative period. Blood
replacement, if required, should continue in the postoperative
period. Clotting studies indicate whether fresh frozen plasma
(FFP) or platelet concentrate needs to be administered. Fluid
replacement should be done to ensure a urine output of at
least 0.5 ml/kg/hour.
Rewarming the patient is another priority in the recovery
phase. This decreases shivering and thus, oxygen
consumption; it also reverses the anticoagulant effect of
hypothermia. Pethidine is sometimes beneficial to treat
immediate post-operative shivering.11 Enteral nutrition should
be started as soon as possible, usually via a nasogastric
tube.
Oxygen administration is always indicated in the recovery
period and should be guided by ABG analysis and saturation.
Reconstructive Phase
By the time, patient reaches this phase, skin coverage has
been complete and all the burn wounds have healed. Caloric
requirements are supplied in excess of those needed and
the anabolism has begun. The pulse rate, respiration and
thermoregulation have stabilized. The anesthesia required is
usually remarkably straightforward unless the face, neck
or airway is compromised in any way.
Reconstruction of shape and function involve release of
contractures and skin grafting, use of flaps, tissue
expanders, etc. The major anesthetic problems during this
phase are airway management, placement of intravenous
catheters and psychological disorder, including post-
traumatic stress disorder or depression. These patients may
return to the operation theater for many years, so the
problems tend to recur. It is important for the members of
the burn team to support them psychologically and plan the
surgery well ahead. Adequate reassurance and premedication
are essential.
Contractures may limit mouth opening and neck
movements in the patient undergoing reconstructive
surgery (Figs 16.9 and 16.10A to E). Visual assessment

218
Principles and Practice of Burn Care
and examination of the patient may aid in the diagnosis of a
difficult airway. If the epiglottis and posterior larynx can be
seen in a seated patient with neck extended, mouth wide
open and tongue fully protruded, one may predict that the
trachea can be successfully intubated. Neck mobility can
be evaluated by asking the patient (in the sitting position) to
place the chin on the chest and look downwards and then
bring the head and neck all the way to look upwards towards
the ceiling behind the head. Restricted neck mobility can
make the intubation difficult. Another useful predictor is
the “3-3-2” rule. The first ‘3’ in the rule refers to the ability
to place three fingers in the patient’s mouth. This examines
the adequacy of mouth opening. The second ‘3’ refers to
the space from the mentum to the hyoid bone. Three fingers
placed side by side should fit into this space. This indicates
adequate mandibular dimensions to permit access to the
airway. The ‘2’ in the rule requires that two fingers be placed
between the thyroid notch and the floor of the mouth (i.e.
the hyoid bone). This indicates that the larynx is sufficiently
low within the neck to permit access by the oral route.
Contracture release on the neck may require special skills
from the anesthetist as the airway may be particularly difficult
to intubate. At times, the surgeon may be required to release
them under local anesthesia, facilitating the intubation (Fig.
16.9). Fiberoptic intubation is the best solution for intubating
such difficult airways, provided the availability of equipment
and expertise (Fig. 16.10). Many times, tissue expanders
are placed under normal skin adjacent to the scarred area.
The bag is slowly inflated with saline solution over a period
of weeks until the skin has been expanded to the desired
size (Fig. 16.11). At times, the inflated expander may cause
problems for the unwary anesthetist. An expander in the
occipital area may cause difficulties with the extension of
the neck in preparation for intubation. Similarly, an expander
in the neck has the potential to cause tracheal deviation or
compression. Provided that the problem is recognized, the
surgeon can be asked to deflate the expander immediately
before the induction of anesthesia. Other methods of
intubation, as mentioned earlier, should be kept in mind and
strategy planned accordingly. The laryngeal mask airway
(LMA) during this phase is safe, has proved its worth and
is an acceptable alternative method to try, whenever
indicated.
Suxamethonium is contraindicated during this phase.
Non-depolarizing neuromuscular blocking agents (NMBAs)
can be safely used. In order to lessen blood loss and operate
in a bloodless field, it is common to use dilute solutions of
adrenaline. The anesthetic agents selected must be
compatible with the surgical use of adrenaline.
Sometimes, skin grafting or local pedicle flaps may be
inappropriate or unavailable respectively for reconstructive
surgery and the surgeon decides to use a ‘free’ flap. These
operations require intricate microvascular surgery and may
be lengthy. Blood loss is slow but persistent. It is vitally
important that the patient’s circulation be maintained in an
optimum condition to ensure that blood flows freely
throughout the newly anastomosed blood vessels. A degree
of hemodilution is desirable, but the circulatory blood volume
must be meticulously maintained and vasoconstriction
avoided.12 The anaesthetist can make useful contribution to
survival of the flap. The patient must be kept warm
throughout the procedure. Cardiovascular status should be
carefully monitored. All blood loss should be replaced, but
crystalloid or colloid rather than blood should be used initially
to achieve an optimum hemoglobin concentration of 10 gm/
dl. A hematocrit of 30-35% will provide adequate oxygen
transport, while minimizing viscosity. Tissue perfusion can
be further improved by the administration of dextran 40
and vasodilators, which act directly on the smooth muscles
of the blood vessels in both the flap and surrounding
tissues.13 After surgery, it is essential to provide adequate
analgesia, because pain causes vasoconstriction and impairs
flap perfusion. In addition, surgeon may request
intraoperative anticoagulation in the form of heparin.
For the operations during this phase, feeding
postoperatively is usually not a problem although a smooth
awakening is important. Coughing, restlessness and shivering
are to be avoided, as bleeding may occur under graft or
graft may be dislodged by movement. The goal should be a
sedated but arousable patient.
Fig. 16.9: A 7-year-old child with severe anterolateral contracture of
neck and face distorting the facial structures and airway structures
completely. Difficult mask ventilation and intubation both because of
restricted mouth opening and inability to extend neck due to contracture

Anesthesia for the Thermally Injured
219
Fig. 16.10A: Severe post burn contracture neck—Front view,
showing the chin touching the chest and severe flexion of neck
Fig. 16.10C: Fiberoptic intubation being tried for the same
patient through nose
Fig. 16.10B: Lateral view of same patient showing total loss of
cervicomental angle with restricted mouth opening
Fig. 16.10D: Patient successfully intubated
Fig. 16.10E: Same patient as in Figure 16.10D after release of the
contracture showing restoration of the cervicomental angle. Neck
can now be extended for easy intubation for future surgeries
Fig. 16.11: Patient with scar on lower face with tissue expander in
neck–Can create problems during intubation

220
Principles and Practice of Burn Care
LOCAL AND REGIONAL ANESTHESIA
Infiltration of donor sites with local anesthetic agents with
a vasoconstrictor reduces both the blood loss and the pain
produced by these wounds. If the donor site is small, topical
application of EMLA cream is highly effective if anesthesia
is not indicated.
The burn wound is classified as an infected area. Thus,
peripheral nerve blocks and regional techniques are relatively
contraindicated as the risk of introducing infection is high.
If the burn is small and the area limited such as a hand
burn, a brachial block may be contemplated.
During the reconstructive phase when these patients
are no longer considered as potentially infected cases, local
and regional techniques may be used. The sympathetic
blockade produces improve blood flow to flaps by dilating
vessels, facilitating tissue transfer. Probably the greatest
limitation to the use of regional technique is the extent of
the surgical field. Most patients with major burns have
multiple operative sites along with the need to harvest skin
graft/flaps from areas too extensive to be easily blocked by
a regional technique.
ANESTHESIA AND ANALGESIA FOR
BURN DRESSINGS
The frequency with which dressings are changed depends
on the condition of wound and type of dressing material
used. A severely burned patient requires many dressing
changes during his/her recovery. The procedure is
frequently painful and if the pain is not relieved adequately,
the patient may become psychologically disturbed whenever
a dressing change is due. It is also stressful for the nurses
and doctors who must inflict pain to the patient. At the
same time, excessive sedation following anesthesia is neither
necessary nor desirable as oral nutrition gets compromised.
Prior to general anesthesia, a period of starvation is
necessary, which makes the administration of an adequate
calorie intake extremely difficult. It has also been said that
the need for starvation makes the routine use of general
anesthesia impractical.14 It is better to have an organized
anesthesia service as a part of burn management team, for
the regular dressing of these patients. The benefits of such
organized service certainly outweigh the disadvantage.
Opioids alone, in general, are often insufficient as pain
is severe and response varies from patient to patient. Hence,
individual titration to effect and frequent reassurance is
important. In addition, most burned patients rapidly develop
tolerance to opioids.
Ketamine is a popular choice with a maximum of 4 hours
of fasting before the dressing change. Ketamine is
administrated in sub-anesthetic doses of 0.5 to 1 mg/kg
body weight, together with midazolam (0.5 mg/kg body
weight). At these doses, the patient is not deeply unconscious
and may even talk and is pain free. Recovery is usually
complete in 20 to 30 minutes. If necessary, the initial dose
of ketamine can be supplemented with 20 mg boluses at
approximately 10 minutes intervals. The duration of sedation
and a number of disturbing psychological sequelae, however,
at times, limits its use. Intravenous propofol and fentanyl in
combination can also be used for dressing changes of shorter
duration. The other alternatives include remifentanil infusion
and general anesthesia. General anesthesia is reserved for
major burns, for the very young child or for intricate
dressings, e.g. to the hand, which take a considerable time.
SPECIAL CONSIDERATIONS
Electric Burns
The burn from electrical current results from the conversion
of high voltage electrical energy to thermal energy.
Determinates of damage include the area of contact, the
duration of current flow and the varying resistance of the
body.
Electrical burns can be associated with gangrene of limbs
and other injuries that may not be immediately obvious.
The extent of injury is also unpredictable. The surface injury
is often small, but the extent of underlying tissue damage
and necrosis is massive. Victims often have concurrent
injuries such as fractures of vertebrae or long bones,
ruptured organs, myocardial injury or numerous contusions.
These patients may be admitted in coma with seizures.
Muscles immediately surrounding the bone are usually more
affected then superficial muscles because bones tends to
provide maximum resistance to the current flow and in the
process produce maximum heat which causes damage to
the deeper muscles. Early fasciotomy is needed to preserve
the blood flow to extremities. It necessitates general
anesthesia during the first day of injury at the time when
fluid shifts, hyperkalemia and myoglobinuria are maximal.
Massive myonecrosis and hemolysis may result in
hyperkalemia as well as myoglobinuria and hemoglobinuria.
In the presence of hemoglobinuria or myoglobinuria, an
increased urine flow of atleast 2 ml/kg body weight/hour
should be ensured by the administration of increased fluids
and mannitol. Alkalization of urine prevents the precipitation

Anesthesia for the Thermally Injured
221
of these proteins in the renal tubules. Follow-up of patients
with electrical injuries often reveals unpredictable sequelae,
which may manifest months to years later; these injures
may occur in organs or areas that do not appear abnormal
during the acute course of illness. These late complications
frequently include neurologic dysfunction, ocular damage,
damage to the gastrointestinal tract, changes in the ECG
and delayed hemorrhage from large vessels. Electrical burns,
most often require much more fluid administration than is
suggested by the extent of surface burn because of extensive
damage of deeper tissues. Therefore, use of standardized
fluid algorithm is not appropriate in these cases.
Pediatric Burns
Thermal injury in children is a common occurrence,
accounting for up to 40% of burn patients and majority of
these are minor scalds. Children are not just small adults,
especially when burnt. There are many differences to be
considered.15
Throughout childhood, the body surface area-to-weight
ratio is increased, tending towards the adult ratio the older
the child gets. This results in more severe physiological
responses to the burn injury. The rise in temperature may
cause febrile convulsions and it may be necessary to actively
cool the child. The resuscitation formulae must be adjusted
to the needs of the child. Drug dosage, fluid requirements
and nutritional needs are more accurately assessed if based
on the surface area rather than the weight.
The inability to communicate well in the younger child
present the anesthetist with a frightened, often crying child
at the preoperative visit. It is important to attempt to gain
the child’s confidence at this time. Preoperative sedation is
desirable for children to reduce the stress of fasting,
transport to the operating room and induction of anesthesia.
Sedation, amnesia and sufficient drying of secretions are
provided with a premedicant dose of trimeprazine supported,
if necessary, by a further dose of IV morphine at the time
of induction.
As IV access may be difficult, an inhalation induction
can be performed and a cannula placed into a vein when the
child is asleep. The use of EMLA cream helps allay the
fears associated with blood-sampling and intravenous
cannulation. Heat loss is greater in the child because of the
greater surface area to weight ratio, thin skin and higher
cardiac output. Every effort must be made to maintain normal
temperatures during surgery. Smaller children can be
operated upon under infrared heaters. Intraoperative
monitoring may prove difficult as previously mentioned,
but the size of the patient adds to these difficulties. Fluid
replacement, blood loss and drugs need special care as these
are affected by the basal temperature, the cardiac output,
the size of the burn, the size of the child and the nutritional
status. The nutritional requirements are high and preoperative
starvation should be kept to an absolute minimum.
Hypoglycemia is common in very small children and must
be guarded against by constant monitoring and an adequate
dextrose infusion.
Ketamine has been used in children as the occurrence
of postoperative problems associated with hallucinations is
reported to be low. This may be due to inadequacy of
communication skills in the child. Other techniques which
includes titrated doses of various drugs like propofol,
morphine, etc. as indicated are preferred that ensure minimal
starvation, swift recovery and early feeding.
Blood loss, when over 10% of the estimated blood
volume, should be replaced, as erythropoiesis is impaired
and there is an increased need of good oxygen transport so
that satisfactory healing occurs.
Pain relief should be measured objectively. Smiling faces
instead of the visual analogue scale may prove successful.
Children of school going age can be taught to use a patient
controlled analgesic device.16 Oral analgesics should be
instituted as early as possible. Many novel ways of
administering analgesia have been tried, all with some
success. These include fentanyl lollipops, fentanyl skin
patches and intranasal fentanyl.
SUMMARY
The anesthetic management of burn patients must include
an understanding of the altered physiology and
pharmacology associated with burns. Proper psychological
support for the family and patient can be greatly facilitated
by a thoughtful and considerate anesthesia care. The
anesthetist is often the friend of such patients if he/she
provides periods free of pain, including the time of transport
from intensive care unit to the operation theater. It is
important to remember that a normal personality resides in
that devastatingly injured body17 and we must remain
sympathetic and supporting at all times and under all
circumstances.
REFERENCES
1. Bryan CP. Minor Surgery. In the Papyrs Ebers, Chapter 12,
Appleton, New York 1931.

222
Principles and Practice of Burn Care
2. Muller MJ. Herndon DN. The challenge of burns. Lancet 1994;i:
216-20.
3. Maclennan N, Heimbach DM, Cullen BF. Anesthesia for major
thermal injury. Anaesthesiology 1998;89:749-70.
4. Eckhauser FF, Billote J, Burke JF, Quinby WC. Tracheostomy
complicating massive burn injury: a plea for conservation. Am J
Surg 1974;126:418-23.
5. Yim KK and Berhow MT. Free skin graft for burn wound. In:
Anaesthesiologist’s Manual of Surgical Procedures edited by Jaffe
RA. And Samulas SI, 3rd edition, Lippincott. Williams & Williams,
Philadelphia, 2004:928-32.
6. Hy YP, HO ST, Wang JJ et al. Evaluation of gastric emptying in
severe burn injured patients. Crit Care Med 1993;21:527-531.
7. Judkins KC, Lord WD. Thermal injury: Anesthesia. analgesia and
intensive care In: Wylie and Churchill Davidson’s A Practice of
anesthesia edited by Thomas EJ Healing and Paul R Knight; 7th
edition, Arnold, London 2003;1105-33.
8. Frei FJ, Ummen hofer W. Difficult intubation in paediatrics. Paediatr
Anaesth 1996;6:251-63.
9. Aun CST. New intravenous agents. Br J Anaesth; 1983(1):29-41.
10. Jensen NF, Kealey GP. Securing on endotracheal tube in the presence
of facial burns or instability. (Letter) Anaesth Anal 1992;75:641-2.
11. Mac Intyre PE, Paulin EG, Dworsteg JF. Effect of meperidine on
oxygen consumption, carbon dioxide products and respiratory
gas exchange in postanesthesia shivering Anaesth Anal
1987;66:751.
12. Sutcliffe A J. Burn patients In: Textbook of trauma anesthesia and
Critical Care edited by Grande CM, Mosby, St Louis, 1993;594-
605.
13. APS C, et al. The role of anaesthetic management in enhancing
peripheral blood flow in patients undergoing free flap transfer. Ann
R Coll Surg Engl 1985;67:177-9.
14. Osgood FA, Szyfelbein SK: Management of pain. In Martyn JAJ,
editor: Acute management of the burned patient, Philadelphia,
1990. Saunders.
15. Rylah LTA, Harper N. Anesthesia for the thermally injured. In:
Anesthesia Review 12 edited by Kaufman L and Ginusburg R, Churchill
Livingstone, London 1995;215-32.
16. Gaukroger PB, Chapman MJ, Davey RB. Pain control in pediatric
burns. The use of patient controlled analgesia. Burns 1991;17:
396-9.
17. Cote CJ. Burn debridement. In: Common Problems in Pediatric
Anesthesia (Ed) Stehling L: 2nd edition, Mosby year book. St.
Louis 1992:207-18.

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223
Biological Dressings and Skin
Substitutes in Burns
17
PK Bilwani, Deepak Nanda
Chapter
INTRODUCTION
The ultimate aim in the treatment of burns is to achieve
wound closure. Wound closure in partial thickness burns
occurs by epithelialization. The main purpose of local care
with antimicrobial creams, non-stick Vaseline gauze and
Gamgee pad dressings in such burns is to prevent infection
and injury to the regenerating neoepithelium till
epithelialization from the surviving epidermal appendages is
complete. It is during this period that the burn wounds have
to be covered with biological dressings and skin substitutes
to reduce pain, evaporative loss of fluids, exudative loss of
electrolytes and proteins and to prevent infection by
preventing contamination. Once the epithelialization is
complete, the biological dressings and skin substitutes either
come out of their own or are peeled off. Wound closure in
full thickness burns is achieved by application of autografts
over the raw areas after the dead skin comes out either
spontaneously or by excisional surgery. However, in
extensive burns, critical level at which donor area becomes
exhausted is from 30-40%; the wounds need to be covered
temporarily with some biological dressing material or skin
substitute till autografts are available. It is calculated that a
person with 50 percent burns requires about 6,000 square
centimeters of skin for coverage of the wound. Once all
the burn wounds have healed, skin cover is still an issue
during reconstruction.
There are various types of biological dressings and skin
substitutes.1-3 An ideal skin substitute should be inexpensive,
readily available, non-antigenic, sterile, durable, flexible and
permeable enough but should not allow excessive water
loss. At the same time, it should provide an effective barrier
to microbes. Unfortunately, such a material is not available
till now. The available skin substitutes can be subdivided
into two types, namely, temporary and permanent.
TEMPORARY SKIN SUBSTITUTES
(BIOLOGICAL)
Amniotic Membrane
Re-epithelialization of a partial thickness skin injury is
facilitated by covering the wound with an amniotic
membrane.4,5 Both human and bovine amnion has been
used as a dressing material. Amnion is readily available,
inexpensive and can cover large areas. Although it does not
get vascularized, it provides an excellent temporary cover
for a few days and enhances re-epithelization in clean second
degree burns or donor areas of split skin grafts. It also
enhances epithelial ingrowth from the wound margins in
full thickness wounds. It exerts an angiogenic effect as
well which increases capillary density of the wound bed.
Amnion can be treated with 0.25 percent sodium
hypochlorite and 200,000 units of penicillin, sterilized, dried
and stored at room temperature up to nine months. However,
its use carries the risk of transmitting diseases like AIDS.
Placenta is procured from normal or cesarean section
deliveries. All aseptic and antiseptic precautions are taken
while handling the placenta. The placental membrane is
dissected from the blood clots with a sterile gauze swab.
Thereafter, it is washed with normal saline and used to cover
the burn wounds. It is immaterial whether chorionic or
amniotic side of the membrane is placed in contact with the
wound. As it does not get vascularized, it does not get
rejected by the body; thereby, allowing its repeated use.

224
Principles and Practice of Burn Care
Amnion can be stored for 2-3 days in sterile bottles containing
0.25% sodium hypochlorite solution. It relieves pain, avoids
discomfort during dressing change, reduces oozing and
protects underlying regenerating epithelium. It is usually
advocated in developing countries where other products
are expensive and out of reach. Amniotic membrane can be
impregnated with antibiotics but the membrane has to be
changed/replaced every two to three days.
Collagen
It is a fibrous protein of vertebrates and forms chief
constituent of the fibrils of connective tissue. It can be
isolated and purified in large quantities from tissues of
animals. Collagen constitutes 25-30% of body protein.
Collagen is hydrophilic and very suitable for cell adhesion.
It has very low antigenicity. It is commercially manufactured
and is readily available in the market as preserved wet as
well as dried sheets6,7 (Figs 17.1A to 17.2). The method of
application is same as for amniotic membrane. The wet
collagen sheet is rinsed in normal saline and spread over
cleaned wounds. Thereafter, it is left exposed to get dry
and stick firmly to the wound. In case of dry collagen sheets
the surface of the wound is wet with saline before application
of the collagen sheet and then covered with a dressing of
gauze and Gamgee. In second degree superficial dermal
burns epithelization occurs under the collagen sheet. When
healing is complete, the dried collagen automatically falls
off. Thus, it provides good biological temporary cover in
superficial and deep partial thickness burns. It also reduces
pain and evaporative losses and forms a barrier for
microorganisms and thus minimizing the chances of wound
infection.
Like amnion, collagen does not get vascularized and
hence adherence to the wound is poorer as compared to
skin grafts.
Homograft (Human/Cadaveric Allograft)8-11
(Figs 17.3A to 17.4C)
In 1881 Girdner treated burns with skin harvested from a
suicide victim. Schede used allografts same year harvesting
skin from fresh amputation specimens and cadavers. Since
then, many workers have used skin allografts as temporary
biological cover in burns. It serves as a temporary cover in
partial thickness burns preventing evaporative loss of
proteins and electrolytes besides relieving pain and misery
Fig. 17.1A: Dry collagen sheet (Skin Temp®)
Fig. 17.1B: Dry collagen sheets applied to an extensive burns in a
child–Majority of the wounds healed within 10 days without any signs
of infection
Fig. 17.2: Wet collagen (Kollagen®) applied to another case of extensive
burns in a child–The wounds are sealed from the environment and
heal fast

Biological Dressings and Skin Substitutes in Burns
225
of dressings. Skin allografts have also been used extensively
for preparing the wounds for grafting. Because of availability
of large skin banks the source of homografts in western
countries is cadavers. However, due to non- availability of
skin banks and lack of public education about skin donations
the surgeons of developing countries procure homografts
from live donors – preferably near relatives. Non-availability
of artificial skin mandates salvage of major burns by
homografts.
The senior author (PKB) has been using skin homografts
in salvage of major burns (above 40%) since 1985. In almost
94% of these cases the source had been voluntary donors
since skin bank facility is not available everywhere. Indian
community is the most wonderful community in the world
where parents and near relatives are always willing to get
admitted and undergo surgery to donate skin for their relative.
In our experience, the homografts are mostly required in
Fig. 17.3A: Homograft from related donor applied to a patient with
extensive burns–On removal of the homograft it shows healthy
granulating wounds
Fig. 17.3B: After removal of homograft, autograft was applied and
fully ‘taken’ up
Fig. 17.4A: Homograft from mother applied in a 4-year-old with
extensive burns–Being removed in multiple sittings for autograft
application
Fig. 17.4B: Autograft applied on healthy raw areas
Fig. 17.4C: Completely healed areas after 1 month

226
Principles and Practice of Burn Care
patients with 50-70% burns. Early excision in this group of
patients is not always possible due to obvious reasons and
they are treated conservatively till all second degree burns
have healed and the third degree burns start granulating.
Thereafter, the important areas are covered with whatever
autografts are available and the rest are covered with
homografts. Once these grafts settle (10-12 days), the
patient’s general condition improves fast. The homografts
get vascularized or ‘take’ exactly like an autograft. They
survive for 3 to 10 weeks before getting rejected by the
body’s immune system. They should be removed from the
wound before the signs of rejection appear as the rejection
reaction can deteriorate the condition of the wounds. For
the coverage of resultant raw areas, autografts can be easily
reharvested.
As the homografts get vascularized like autografts
(particularly the fresh homografts), they form best biological
dressing material in reducing pain and the bacterial density
of the wound. If skin bank facility is available the homografts
can be freeze-dried and stored for longer time though their
viability diminishes as the time passes.
Heterograft (Xenografts) (Figs 17.5A to C)
As homografts are difficult to procure, surgeons have used
skin procured from porcine or bovine or canine sources.
However, the xenografts do not get vascularized and hence,
their tissue adherence property is poor and not much
effective in preventing bacterial proliferation. They do prevent
Fig. 17.5A: Granulating burn wound
Fig. 17.5B: Wound covered with porcine
xenografts
Fig. 17.5C: Epithelialization under porcine
xenografts
evaporative losses and relieve pain. The religion of the patient
poses a hurdle in the use of xenografts with respect to its
source.
TEMPORARY SKIN SUBSTITUTES
(SYNTHETIC)12,13
The synthetic skin substitutes (synthetic dressing materials)
though available “Off the shelf”, lack property of adhesion
and hence sub-membrane suppuration is common. The
various synthetic skin substitutes consist of films like
polyurethane (Opsite, Biobrane). Foams like polyurethane
foam (Looms), gels like amiderm, duoderm, Kaltostat etc.
and sprays like polyhydroxyethylene methacrylate.
Biobrane (Winthrop Pharmaceuticals,
Santa Ana, CA)
It is a two layered temporary, synthetic skin substitute. The
outer layer is composed of ultrathin layer of silicon rubber
which is semi-permeable and permits the exit of water
vapours but prevents entry of bacteria from the exterior.
The inner layer is tightly woven nylon fabric. Both layers
have porcine collagen peptides covalently bonded which
allows the sheet to adhere to the wound by integration of
tissues without causing inflammation. The collagen is slowly
replaced with host tissue. Biobrane (Fig. 17.6) is translucent
allowing observation of wound healing through it. It is elastic
and confirms to irregular surfaces. When donor sites for
autografts are available, the silicon sheet is removed and

Biological Dressings and Skin Substitutes in Burns
227
autografts are applied. It should preferably be removed in
about two weeks to prevent fibroblast ingrowth into the mesh.
Transcyte (Advanced Tissue Sciences, La
Jolla, California)
It is a bi-laminate synthetic, temporary skin substitute. The
dermal layer is composed of a layer of collagen synthesised
by human neonatal fibroblasts cultured on a nylon mesh.
The epidermal analogue is made up of silicone. It is better
than cadaveric skin as it can be easily removed with less
bleeding but leads to equal or better take of autografts. There
is no apparent immune mediated rejection.
Omniderm (Omikron Scientific Ltd,
Rehovat, Israel)
It is a temporary synthetic skin cover which is thin,
transparent and flexible membrane of polyurethane. It is
hydrophilic, absorbs water and is elastic in nature. It is
permeable to liquid and can be used as an interface for skin
grafting (as a layer between graft and the dressing). It allows
water vapor to evaporate and allows antibiotics to permeate
inside.
Apligraf (Graftskin)(Organogenesis Inc.,
Canton, MA)
This manufactured skin analogue is composed of two layers,
viz., the epidermal layer made of human foreskin derived
neonatal keratinocytes and the dermal layer made of neonatal
fibroblasts seeded in Bovine Type 1 collagen lattice. This
has been shown to improve the cosmetic results when applied
over widely meshed grafts.
Opsite/Cling Film/Via Film
It is a synthetic adhesive moisture vapor permeable dressing
made up of modified polyvinyl chloride. Although it is
permeable to water vapor, it is impermeable to bacteria.
The permeability to water is low; at times can lead to
collection under this dressing. Pain relief, lack of bulky
dressings and early healing are the advantages.
PERMANENT SKIN SUBSTITUTES
Dermal Replacement-synthetic
Integra (Integra Life Sciences Corporation, NJ)
(Figs 17.7A to G and 17.8A to D)
This is a synthetic, bi-laminate product designed to provide
permanent skin cover, with outer epidermal substitute made
up of silicone (polysiloxone polymer) layers which controls
moisture loss from the wound bed. The deeper dermal
analogue is made up of bovine tendon collagen arranged in
a three dimensional porous matrix and cross-linked with
glycosaminoglycan (chondroitin-6-sulfate, derived from
shark cartilage). With its use the dermal layer is infiltrated
by fibroblasts. This is followed by capillary invasion which
vascularizes and leads to deposition of collagen by fibroblasts
and the dermal matrix gradually biointegrates with the
wound. The silicone layer separates out in 2-4 weeks time
when a thin split skin graft coverage shall be required to
cover the neo dermis.
Integra has been used since 1981(Burke et al) and
subsequent trials have concluded that hypertrophic scarring
was less, late contractures were rare and artificial skin
grafted areas demonstrated growth with the growth of the
child.
Derma Graft (Advanced Tissue Sciences,
La Jolla, California)
This synthetic dermal matrix is made by seeding neonatal
fibroblasts on to a polyglactin vicryl mesh. It is usually
used on excised burn wounds with a split skin autograft.
Gradually over a month the mesh gets absorbed. The graft
uptake on the matrix is slightly less than autograft alone but
shows more resistance to bacterial contamination.
Fig. 17.6: Biobrane applied over hand burn (Courtesy: Smith and
Nephew Ltd.)

228
Principles and Practice of Burn Care
Fig. 17.7A: Sample of integra (Courtesy: Integra
lifesciences corporation)
Fig. 17.7B: Line diagram of integra showing the upper silicone
sheet and lower dermal matrix
Fig. 17.7C: Integra applied on face following excision of deep burns
(Courtesy: Integra lifesciences corporation)
Fig. 17.7D: Following application of skin graft
Fig. 17.7E: Quality of skin following complete healing of wounds
Figs 17.7F and G: Unrestricted mobility of lids
F
G
Dermal Replacement—Biological
Alloderm: It is de-cellularized allograft dermis. It is prepared
by a special biochemical process to make the human dermis
acellular. It is used as a dermal transplant in deep second
degree and third degree burns. Donors are screened for HIV
1 and 2, HBV, HCV, HTLV 1 and Syphilis serologically. Then
the material is freeze dried and stored. After wound excision
the dermal matrix is grafted on to the fresh wound and

Biological Dressings and Skin Substitutes in Burns
229
covered with split skin graft. There are fewer incidences of
inflammation and infection.
EPIDERMAL REPLACEMENT
Cultured Keratinocytes (Epidermal cells)14,15
Rheinwald and Green in 1975 found that irradiated murine
fibroblasts can support the growth of human fibroblasts.
In this technique a culture medium of fetal calf serum is
used to grow keratinocytes into confluent sheets of
epidermis. These epidermal sheets are usually two to eight
layers thick. By regular sub-culturing, a three square
centimeter sheet can be expanded five thousand times
yielding almost enough epithelium to cover the whole body
surface of an adult human. This level of expansion requires
sophisticated labs and a large number of staff and is routinely
impracticable. This topic is covered in more detail elsewhere
in the book.
Cultured Allogenic Keratinocytes
This has the advantage of unlimited supply and is
immediately available. Cultured epidermal allografts have
been successfully used even after cryo-preservation. Initially
the survival of this allograft was thought to be because of
elimination of Langerhans’ cells during the cultivation
process which is assessed by a lack of HLA-DR expression.
Indefinite cell survival in the allograft is controversial, the
long term wound healing is suggested to be due to the residual
host keratinocytes whose growth and migration is stimulated
by cultured allografts. The disadvantage is that it still carries
the possibility of disease transmission.
COMPOSITE EPIDERMAL AND DERMAL
REPLACEMENT
Composite (Dermal-epidermal) Cultured Grafts
Although cultured epidermal sheets have been successful
in some cases, they have following disadvantages (1)
Epidermal sheets lack dermis and therefore do not
vascularize adequately on full thickness wound beds and
hence do not adhere satisfactorily. (2) Epidermal sheets lead
to extensive scar formation. (3) In normal skin presence of
rete ridges at dermal epidermal junctions (DEJ) provides
resistance against shearing forces. However, following
application of cultured epidermal sheets in full thickness
wounds, the epithelium is unstable due to the lack of rete-
ridges and may get easily detached.5
Figs 17.8A to D: (A to C)Application of Integra after excision of deep
dermal wounds on upper arm and dorsum of hand. (D) Final healed
area on the dorsum of hand after removal of silastic sheet after 21
days and application of thin split skin graft
A
B
C
D

230
Principles and Practice of Burn Care
The above disadvantages with the use of cultured
epidermal sheets clearly indicate that dermis component is
essential for satisfactory wound healing. Hence, for optimal
wound healing Dermal-epidermal grafts are developed by
growing epithelium on a dermal substrate. The dermal
substrate is derived from either collagen-gel-fibroblast or
Allograft Dermis.
REFERENCES
1. Alsbjorn BF. Biologic wound coverings in burn treatment. World J.
Surg 1992;16:43.
2. Arthur S, brown, Lenora R Barot. Biological dressing and skin
substitute’s. Clinics in Plastic Surgery, 1996;13(1)69-74.
3. Norton L, Chvapil,M: Comparison of newer synthetic and biologic
wound dressings. J Trauma 1981;21:463.
4. Quinby WC, Hoover HC, Scheflan M, et al. Clinical trials of amniotic
membranes in burn wound care. Plast Reconstr Surg 1982;70:711.
5. Sawhney CP. Amniotic membrane as a biological dressing in the
management of burns. Burns 1989;15:339.
6. Chhatre MG and Mani MM. Biological Dressings and skin substitutes.
Handbook of Burns Management Editors Jaypee Brothers Medical
Publishers (P) Ltd. 1991;135-39.
7. Yang JY. Clinical application of collagen sheet as a burn wound
dressing, YCWM 1990;16:457.
8. Bilwani PK. Skin Donation an overview of 26 years experience.
Indian Journal of Burns 2005;13:18.
9. Bilwani PK, Gupta Ruchi. The epidemiological profile of Burn
Patients in LG. Hospital, Ahmedabad Indian Journal of Burns
2003;11:63-4.
10. Bilwani PK, Sheth H. Use of Lyofoam as a dressing for split skin
graft donor sites. Indian Journal of Plastic Surgery 1988;21:
38-40.
11. Shuck JM, Pruit Basil A and Moncrief JA. Homograft Skin for
wound coverage. Arch Surg 1969;98:472.
12. Chester DL, Papini RPG. Skin and skin substitutes in burn
management. J Trauma, 2004;6:87-99.
13. Eran Bar-Meir, David Mendes and Eyalwinkler . Skin substitutes .
IMAJ, 2006;8:188-91.
14. Hansbrough John F. Cultured epithelium for wound closure. Wound
Coverage. R.G. Landes Company, Austin 1992;75.
15. Rheinwald JG, Green H. Serial cultivation of human epidermal
Keratinocytes: The formation of keratinizing colonies from single
cells. Cell 1975;6:331-44.

Skin Banking
231
Skin Banking
18
Sujata Sarabahi, Deepak Nanda
Chapter
INTRODUCTION
An extensive burn injury involves loss of large amounts of
normal skin leaving insufficient donor sites for coverage of
wounds with skin autografts. The best treatment for a partial
thickness burn wound is its coverage with some dressing
which can protect it from infection and injury and allow it
to heal at the earliest. Full thickness burns, obviously, need
coverage with skin graft. Skin is the best biological dressing
whether it is autograft, homograft or xenograft. Homografts
have been in use for treatment of extensive burns for many
decades as they provide an easy and practical method for
temporary wound closure, despite having their own
limitations. Homografts can be obtained from either living
donors or cadavers. It is usually difficult to get fresh
homografts in large amounts unless the donor is a live-
related donor which is a very rare situation. For such cases
the grafts may be harvested as and when required and
therefore, banking of the skin is not required. Cadaveric
skin grafts are a good choice when requirement is large.
Their use in extensive burns requires establishment of skin
banks for their storage till such time that they can be used.
This is because they have to be harvested even when there
is no immediate requirement of the homograft.
Skin banks provide facility to store not only cadaveric
skin but also for the skin from amputated parts, xenografts
and amnion, etc. With the establishment of skin banks in
association with major burn centers, the morbidity of
extensive burn patients has reduced dramatically.
It is well known that the viability of skin graft begins to
decline as soon as it is harvested and lifted off the donor
site. The rate of decline depends on many factors, the main
being the temperature at which it is stored. The cellular
viability is inversely proportional to the temperature at which
it is kept. If the skin grafts can be rapidly cooled in a well
oxygenated medium, their viability may be prolonged.
Wentscher1(1903) was the first to refrigerate free skin
as autografts, one sample for seven days and three for
fourteen days. All but one of them survived. After continuous
experiments, Carrel2, 3 concluded that Vaseline was the most
satisfactory medium for refrigeration and in 1911 he
suggested to the surgeons that refrigerated skin can be used
for clinical advantage. Kubanyi (1930), in his experiments,
preserved autografts in patients own serum and applied it
after 12 days of their harvest (as quoted).4 He showed that
these grafts survived for 8 days after transplantation. It
was, therefore, established that apart from providing a low
temperature, a cryo-protective medium is also essential to
maintain the cellular structure of the graft.
METHODS FOR SKIN STORAGE
There are various methods for storing the skin graft.
1. Refrigeration: It is the most commonly practiced
method as it is easily available at every centre. The graft
is kept in the refrigerator at 4°C in a sterile bottle after
wrapping it in a Vaseline gauze (epidermal side on gauze)
followed by saline soaked gauze pieces. The raw surface
of the graft is to be kept in contact to prevent excessive
evaporation. When grafts are required for clinical use,
the outer layers of Vaseline and saline gauze are removed
and grafts washed with saline before being applied to
the raw areas in the same manner as fresh grafts.
This method is used mainly for autografts and in
this manner the grafts can be stored for up to 3 weeks

232
Principles and Practice of Burn Care
although the viability of the graft decreases with time. It
is best used within a week after which there is a definite
deterioration in the skin structure affecting its ‘take’.
This hypothermic storage technique can be improved
to prolong the useful period of graft storage by keeping
the grafts in a cryo-protective medium like dilute
homologous serum, tissue culture medium or balanced
salt solution as sources of nutrient to the skin cells.
2. Deep freezing or cryo-preservation: It involves the
cooling of tissues to ultra low temperatures. However,
at below 0°C temperature, there is disruption of
cytoplasmic contents of the cells leading to a mechanical
rupture of the cells. To reduce this effect and improve
the cell viability, the tissues have to be pretreated with
cryo-protective agents. They can now be slowly cooled
to very low temperatures with minimal molecular
damage. The agents used are glycerol, ethylene glycol,
dimethyl sulfoxide, etc. whose freezing points are below
minus 300°C so that they do not form any crystals. The
cooling is done by using liquid nitrogen to temperatures
as low as minus 80 to minus 196°C and then stored by
placing them in deep freezers or submerging them in
liquid nitrogen. Usually liquid nitrogen flasks are used
for transporting homografts from skin banks to the burn
centers for use. Grafts cooled to minus 80°C can be
stored for 6 months while those cooled to minus196°C
can be stored indefinitely.
3. Freeze drying or Lyophilization: It is the process where
the graft is first rapidly cooled and then the water is
removed by sublimation and the tissue is vacuum sealed.
These grafts are sterilized by gamma irradiation. These
freeze dried grafts are stored at room temperature and
are nonviable since the skin cells do not survive
dehydration. These grafts do not ‘take’ and serve as a
biological dressing only.
HOMOGRAFT SKIN BANKING
Harvesting
Split skin grafts are harvested from refrigerated cadavers
within twenty four hours of death. Signed consents are
required from appropriate relative(s) for the purpose. Skin
donations are acceptable from individuals between the age
of twelve and sixty years with no history of malignancy,
hepatitis, jaundice, dermatological disorders and venereal
diseases. Blood samples taken from the cadaver are tested
serologically for AIDS (HIV 1 and HIV 2), Hepatitis B,
Hepatitis C and syphilis.
All the donor sites are shaved and prepared. Skin grafts
are harvested taking all aseptic and antiseptic measures
exactly similar to surgical operations being carried out in
live patients. Using dermatomes strips of split skin grafts
are harvested in thickness varying between 0.25 mm to
0.35 mm from limbs and trunks. After harvesting, a
representative piece from each area is sent for
microbiological testing for Streptococcus, Pseudomonas and
Staphylococcus. Any skin graft whose sample produced
more than 10 organisms/gm of donor tissue, is discarded
as it is unsuitable for treatment of burn wounds.
Cryo-preservation5
After the skin grafts have been harvested they are spread
on meshed Vaseline gauze with epidermal side on the gauze.
The length of skin strip dictates the number of times the
skin has to be folded on itself. It has been seen that strips of
skin 40 cm or more in length have to be folded twice. These
sheets are then rolled and packed into sterile plastic
containers. These containers are immediately immersed in
a sterile solution of 15% Glycerol and Ringer Lactate at
4°C for two to four hours. This period provides time for
the cryo-protectant to enter the cells of the tissue in order
to prepare the skin for freezing later. Other cryo-protectants
which are used are Dimethylsulphoxide, Ethane-diol and
Propane-diol but Glycerol is still the most commonly used.
In DMSO the time required for the cryoprotectant to enter
cells is 30 min. whereas in glycerol it takes a minimum of 2
hours. After about four hours the solution is poured off and
the skin strips are transferred to polyester plastic envelopes
which are heat sealable. The envelopes are then labeled
properly with name, mortuary number of the patient and
the date of skin harvest and thermo sealed. The envelopes
are weighed and the size of skin and the weight are recorded.
If the harvested skin is urgently required, the glycerol
solution step is omitted and skin stored in the refrigerator at
4°C in sealed envelopes as above. In this way, the skin can
be stored for a maximum of 10 days. However, it is best
used within 3 days by which time serological test results of
AIDS and Hepatitis, etc. are available.
Freezing of skin can be done in two ways, controlled or
uncontrolled. Controlled freezing involves bringing the
temperature down by 1° per minute to about minus eighty
to minus hundred degrees Celsius while in uncontrolled
freezing the skin strips are directly transferred to the
refrigerator at minus 70°C or into liquid nitrogen vapor
where temperature goes down to about minus 100°C. In
controlled cooling, the viability of skin keratinocytes and

Skin Banking
233
fibroblasts is maintained but the immunogenicity is reduced
(as assessed by mixed epidermal cell/lymphocyte response)
by 95% in murine allografts. The major immunostimulatory
cells in the skin are the Langerhans’ cells which are
differentially inactivated. Temperature probes are embedded
into the deepest layers of skin to give a feedback and from
these it is evident that controlled cooling is better than the
uncontrolled one. The latter produces ice crystals inside
the cells which cause mechanical damage and it also changes
intracellular osmolality (produces hyperosmolality) which
affects skin viability. This is more evident in thin flat packets
which undergo rapid cooling. After controlled cooling, the
skin packets are stored either by being submerged in liquid
nitrogen or in electrical freezers with modified aluminum
drawers having slots for skin packets. Skin in this condition
can be stored indefinitely till it is required. The disadvantages
of storage in liquid nitrogen are that both loading and
retrieving are cumbersome. Proper ventilation is required in
the room that houses the liquid nitrogen apparatus.
Following the harvesting of a skin graft, the vascular
supply of the cells is totally cut off and there is a decline in
skin viability because of the following reasons:
1. Lack of nutrients and oxygen.
2. Build up of toxic materials.
3. Generation of free radicals causing lipid peroxidation
4. Osmotic changes
5. Uncoupling of biological pathways.
Addition of homologous serum in a concentration of
10-35% has been found to be beneficial in reducing this
decline in the tissue viability. Not only it provides nutrition
to the graft but also dilutes and buffers the acids produced
during metabolism. Tissue culture medium is also used to
provide nutrition and neutralizing harmful metabolic by
products.
The requirement of oxygen has been found to be
temperature dependent. At 6-8°C cells require oxygen but
at 0 degree and below there is no requirement of oxygen
any more and in fact, it is detrimental. Hyperbaric oxygen
and 100% oxygen have been found to be harmful and this
probably indicates the detrimental role of oxygen free
radicals. Enzyme Superoxide Dismutase helps in maintaining
viability of stored skin, the higher the level of SOD the
longer the period of cell survival.
Osmotic changes take place in stored cells which are
detrimental to the cells. These changes are due to slowing
down of Na-K-ATPase pump. At 5°C, it works at about 1%
of its normal capacity with subsequent influx of sodium,
chloride and water leading to cell edema. This can be
prevented by adding impermeable solutes to make the
solution hyperosmotic or by using an intracellular salt solution
to obviate the effects of ionic differences between intra and
extracellular compartments. University of Wisconsin solution
and CP Test are examples.
Although our understanding of detrimental effects of
low temperature on tissues and cells has improved, not much
has been achieved in improving the process of hypothermic
skin storage.
Rewarming
When the stored skin graft is required, a rapid re-warming
has to be done so that its viability is preserved. It is done by
re-warming at a rate of 50-70°C per minute. This can be
done either by placing the packets in a microwave oven at
lowest microwave setting or by placing the packets into a
two liter jar of water at 42°C until there is equilibrium between
skin and water. Water gives rapid warming irrespective of
size of packets. Skin stored in flat packets can be warmed
ten times faster than the skin rolled into cylinders. The longer
time taken to thaw the skin stored in cylinders is
disadvantageous for the skin. The other disadvantage is that
the cylinders occupy more space. The skin graft, after being
thawed, has to be applied within two hours.
Some experiments have been done to test the viability
of stored skin including enzyme levels of cells or oxygen
consumption by the skin. Wachtel et al6 conducted
experiments comparing the viability of fresh allograft, frozen
allograft thawed in a microwave, frozen allograft thawed
by saline bath and fresh autografts. All the grafts were applied
as a mesh. He found that in autografts, the graft adhered
and the interstices closed in twelve days, fresh allografts
adhered but interstices closed in sixteen days, the frozen
allografts whether thawed by microwave or saline-bath
adhered for about thirty days but did not grow. Histological
examination shows that in 3-weeks time most of the
epithelium dies. The dermis is edematous with chronic
inflammatory cells and there are no signs of
neovascularization. Both the skin samples, whether thawed
by microwave or warm saline, showed no histological
differences. They also found that samples with more than
10 organisms were involved with rejection. Refreezing and
thawing decreased viability by about 40 percent.
Microbial assessment of the skin is done, while in
storage, as this skin has to be applied to immuno-
compromised burnt patients. Bacterial enzymes and toxins

234
Principles and Practice of Burn Care
reduce tissue viability. Testing is done for Staphylococcus
epidermidis, Staphylococcus aureus, E.coli and Asperigillus.
May and Wainwright7 found that one skin sample yielded
correct skin microbial assessment 92% of times, five
samples yielded correct microbial assessment in 96% of
times and ten samples yielded 99.9% correct results.
Pre harvesting preparation of skin is the most important
factor in controlling infection of the stored graft. Protection
against AIDS and Hepatitis B and Hepatitis C is vital and
serology must be done carefully and routinely for donors.
For medico-legal purposes, it is advisable to have serological
tests done on the recipient patient as well.
FUTURE
Continuous efforts have been made over the years to improve
the chances of ‘take’ of homografts. Cryo-preserved
homograft were abraded to remove the epidermis and then
super-imposed with cultured keratinocytes as described by
Cuono et al.8 Removal of homograft epidermis eliminates
most of the HLA-DR antigens. GaoZhi-Ren et al9 from China
inoculated homograft skin with uncultured epithelial cells
into the dermal layer while still in situ on the cadaver. The
combination was removed and grafted to the patients. The
epithelial cells grew by day forty and covered the whole
wound.
Sawada10 from Japan used small pieces of autografts (3
× 3 mm fragments 10 mm apart) and covered with big
sheets of meshed homograft skin. Yang et al11 described
something similar where they made holes in the covering
homograft skin and introduced small pieces of autografts.
Homograft ‘take’ is helped considerably by
immunosuppression, like other organs, as shown by Burke
et al.12 They used Azothioprine and anti-thymocyte globulin
which are highly toxic. Cyclosporin A has gained a lot of
popularity due to its efficacy and safety. Achauer et
al13showed that when Cyclosporin A was given for 120
days homograft skin stayed viable for two years.
SUMMARY
Cadaveric homografts have an established role to play in
saving an extensively burnt patient. For them to be most
effective, they must be properly harvested, microbiologically
tested and correctly frozen and stored. Though the use of
skin homografts has its own limitations because of its
immunogenic response, techniques are being developed to
overcome these problems in future. The skin allografts are
inexpensive compared to other organ transplants except the
process of banking which is costly and therefore, not
available at all burn centers. There is, therefore, a need to
establish more of such skin banks so that the facility of
cadaveric homografts is available for treating extensive burn
patients at all centers.
REFERENCES
1. Wentscher J. Ein weiter betirag zur uberlebenfahigkeit der
meschilichen epidermiszellen. Deutsche zeitschrift fur chirurgie
1903;70:21-44.
2. Carrel A. Rejuvenation of cultures of tissues. Journal of the American
Medical Association 1911;57:1611.
3. Carrel A. Preservation of tissues and its application in sugery.
Journal of the American Medical association. 1912;59:523-7
4. Jerome P Webster–Refrigerated skin grafts Annals of surgery
October 1944;431-41.
5. GA Fielding, SP Pegg. Homograft skin banking- current practices
and future trends. Aust NZ. Journal of surgery 1988;58:157-9.
6. Wachtel TL, Ninnemann JL, Fischer JC, Frank HA. Viability of
frozen allografts. American Journal of Surgery 1979;138:783-7.
7. May SR, Wainwright JF. Integrated study of the structural and
metabolic degeneration of skin during 4 deg C storage in nutrient
medium. Cryobiology 1985;22:18-34.
8. Cuono CB, Langdon R, Birchall N, Barttelbort S, Mc Guire J.
Composite autologous allogenic skin replacement; Development
and clinical application. Plas Reconst Surg 1987;80:626-35.
9. Gao ZR, Hou ZQ, NIe LJ, Liu GF. Coverage of full skin thickness
burns with allografts inoculated with autogenous epithelial cells.
Burns 1986;12:220-4.
10. Sawada Y. Survival of an extensively burnd child following use of
fragments of autografts skin overlain with meshed allograft skin.
Burns 1985;11:429-33.
11. Yang CC, Shih TS, Chu TA, HSU WS, Kuo SY, Chou YF. The
intermingled transplantation of auto and homografts in severe
burns. Burns 1980;6:141-5.
12. Burke JF, Yannas IV, Quinby WC, Bondoc CC, Jung WK. Successful
use of a physiologically acceptable artificial skin in the treatment
of extensive burn injury. Annals of Surgery 1981;194:413-28.
13. Achauer BM, Hewitt CW, Black KS. Long term skin allografts
survival after short term cyclosporine treatment in a patient with
massive burns. Lancet 1986; 14-5.

Keratinocyte Culture
235
Keratinocyte Culture
19
RP Narayan
Chapter
INTRODUCTION
An early burn wound healing is a cherished desire not only
of the burn victim but also of the treating burn surgeon.
Superficial dermal burn wounds heal spontaneously within
three weeks if optimal conditions for healing are ensured.
Very deep dermal burns either take very long time (up to 6
weeks) or may even fail to heal with lots of undesirable
complications like contracture and ugly scars, etc. To
circumvent these, surgical intervention in the form of skin
grafting is required. Finding requisite amount of split skin
graft from available donor sites is a common problem in
extensively burnt patients. A large variety of skin substitutes
and dressings are used to temporarily solve the problem.
The management of burn wound has evolved over the
past several decades. Early excision and grafting has become
the standard of care for surgical management of the burn
wound. In cases of extensive burns where total body surface
area burnt may exceed the available donor sites, there arises
a need for replacement of human skin. The skin replacement
technologies introduced over the past two decades or so
have positively impacted burn care. Efforts have been
focused on temporary and ideally permanent replacement
to native human skin.
Serious short and long term problems occur when the
epidermal and dermal layers of skin are destroyed. The short
term problems, which can be life threatening, include the
loss of protein rich fluid and invasion of bacteria and other
microbes. These essential barrier functions are provided by
the epidermis which consists of keratinocytes attached to
an underlying basement membrane. The dermal layer
provides for the durable and pliable characteristics of skin,
which are so vital to proper skin function and cosmesis.
When available, the replacement material of choice is the
patient’s own (autologous) skin to treat acute burns.
Autologous split-thickness skin graft is closest to being the
ideal skin substitute. One of the major problems in extensive
burns is the relative lack of available replacement by
autologous skin and the well known limitations of homograft.
This brings to attention the importance of skin culture and
how it can help us overcome the above problems.
HISTORY OF KERATINOCYTE CULTURE
Healing of partial thickness burn wounds (epithelialization)
occurs from basal epithelial cells (keratinocytes) of epidermis
and skin appendages (hair follicles and sweat glands).
Attempts of growing autologous keratinocytes in laboratory
for coverage of burn wounds have been in practice for the
last few decades. Keratinocytes have been known to be
difficult cells to grow because of their limited proliferation,
early differentiation and frequent contamination with
fibroblasts. Cultured epidermis for human use in burns was
first proposed by Pickerill in 19511 and in 1956. Basset,
Evans and Earle2 also proposed that epidermal cell culture
in massive quantity could provide a solution for wound
closure in burns. Since then, efforts have been made to
develop techniques for growing the transplantable epidermis
(Karaseck, 1968)3 in vitro. The importance of fibroblasts
in epidermal growth and differentiation has also been
demonstrated. Later on, works by Green and associates
(Rheinwald and Green, 19754; Green et al 19795) have
demonstrated the techniques for serial cultivation and
differentiation of keratinocytes and proposed logistical