Burn
Definition: is the tissue injury from thermal application or from
absorption of physical energy or chemical contact.
Classification of burn:
1-physical:
Scald: burn caused by hot liquid.
Fat burn: cooking fat has much higher temp. (180c) than boiling water.
Flame burn: many causes e.g. clothing fire, house fire.
Electrical burn: passage of electrical current cause tissue injury. A
common phenomenon is progressive loss of viable tissue. Muscle tissue is
vulnerable.
Friction burn: due to combination of heat and abrasion.
Ionizing radiation: tissues necrosis may not develop
immediately. And injury limited in the area.
2-chemical burn:
Strong acid and alkali.
Certain industrial and domestic chemicals.
Usually chemical burn cause local coagulation of protein and necrosis,
some have systemic effect.
Burn severity:
The depth and extension of burn depend on:
1-Temperature of the burning agent.
2-Mode of heat transmission (contact, radiation, flame)
3-Duration of contact.
4-skin thickness.
Effect of burn:
Local effect:
The burn area subdivided into 3 zones:
1-Zone of coagulation: which most affected area by heat, in this area
there is no blood flow and is nonviable.
2-Zone of stasis: in this area there is microvascular sluding and
thrombosis of vessels soon result in progressive tissue necrosis.
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3-Zone of hyperemia: outmost zone, which entirely viable, which
sustained minimal injury. This zone contributes to systemic consequence
seen in major burn.
Also wound infection occurs as damaged tissue represented nidus for
infection.
Systemic effect:
1-shock:
A-neurogenic shock due to pain
b-hypovolumic shock from damaged capillaries either externally or
internally, most likely mediated by cytokines acting on microcirculation.
2-multiple organ failure: there is progressive failure of renal or
hepatic or heart failure, exact mechanism unknown. And may be
attributed to fluid loss, toxemia from infection or overreaction of
inflammatory response to sepsis.
3-Depressed immunity, wound infection and septicemia.
4-Inhalation injury: mechanism of inhalation injury could be the
fallowing:
 Carbon monoxide (CO) .Which has affinity for Hb 210 times more
than O2.When CO enter cell cytochrom system it impaired O2
utilization.
 Direct thermal injury to lower airway which lead to direct mucosal
damage and edema.
 Inhalation of products of combustion which is the most common
cause of inhalation injury e.g. of product of combustion aldehyde,
keton.
5-GIT problems: curling (gastric or duodenal) ulcer, ileus.
6-Anamia, urinary tract infection from cathetrizaton, deep
venous thrombosis (DVT) from prolongs immobilization and
pulmonary embolisms.
7-Scarring and contracture.
8-psychological trauma.
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Assessment of burn depth:
Skin anatomy:
Epidermis is the most superficial layer of skin; the dermis is thicker
underlying area which has rich blood supply and contained adenxal
structures such as hair follicles, sebaceous gland and sweat gland.
1-Superficial burn: the prototype is sunburn with erythema and mild
edema, the involved area is tender and warm. Such burn heals rapidly
without sequel by epithelization within 14 days.Usaully heals without
scar, but sometime leave.
2-partial thickness burn: involved the uppermost layer of dermis.
The hallmark of partial thickness is blisters formation.
3-Full thickness burn: complete destruction of all epidermis and
dermal element, the skin a appeared waxy, translucent with thrombosis
vessels beneath the translucent skin. The charred layer which covered this
burn consists of denatured, contracted dermis called eschar.
Indication of hospital admission:
 Partial thickness more than 15% in adult
Partial thickness more than 10% in children.
 Full thickness burn more than 5%.
 Both extreme of age.
 Serious medical illness.
 Burn of face, hand, feet, perineum.
 Inhalation injury.
 Electrical injury.
Management:
Initial management:
1. Stop the burning process by removal the patient to safe place.
2. Immediate cool the burn surface with cold water or under tape,
hypothermia must be voided.
3. Wrap the patient in clean linen and then transfer to hospital.
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General treatment:
When burn patient reach the emergency room we should not only
concentrated on burn since many patents have also other injuries like
chest or head injuries. So rapid examination should be done to exclude
associated injuries.
1-maintenance of airway: Endotracheal intubation is indicated if
patient:
 Semicomatose.
 Deep burn to face and neck.
 Critically injury.
Intubation should done early .since with development of burn edema (812 hours)the intubation will be difficult.
When intubation is difficult, tracheostomy should do.
2-Fluid resuscitation: Initially should established good I.V. line
In non burn skin, when difficult, may used venous cutdown.
A Foley catheter should insert to measure urine output.
Fluid and electrolyte given according to:
Parkland formula: 4ml×Kg(body weight) × burn%. In the form of
Ringer lactate in first 24 hours post burn.
 1\2 the dose in Ist 8 hours post burn
1\2 is given over the final 16 hours.
 In the 2nd 24 hours, 5% dextrose is given to maintain urine output
(30-50ml\hr in adult, 1ml\Kg\hr in children).
 In third 24 hours change to maintenance I.v. fluid, oral intake and
\or enetral feeding. When there is vomiting or diarrhea, the
requirement increase.
Plasma replacement can be given according to:
Muir and Barclay formula which:
Burn%× weight (Kg) /2= one ration (ml) plasma or dextran.
3 rations are given in 1st 12 hours.
2 rations are given in the 2nd 12 hours.
1 ration is given in the last 12 hours.
The adequacy of resuscitation guided by:
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A-clinical guides:
 Consciousness, orientation.
 Pulse rate, blood pressure.
 Respiratory rate, basal crepitation.
 Appetite, bowel motion, abdominal distension.
 Urine output 0.5-1ml \Kg\hr.
 Skin turgor and temperature.
B-Laboratory guide:
 Hourly urine output and specific gravity.
 Packet cell volume(PCV)
 Acid base status
 Blood urea and electrolytes
 CVP (central venous pressure)
3-Antibiotics.
4-Tetanus prophylaxis.
5- GIT protection by using antiacid or cimitedine for
prevention of Curling ulcer.
6-pain relief by using small dose of morphine titrated to
clinical responses of patient.
7-High protein and caloric dietary support.
8-psychological support.
9-Rehabilitation and physiotherapy.
Surgical management of burn:
Indication:
1. Safe life ( Tracheostomy).
2. Reduced hospitalization.
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3. Wound sepsis.
4. Reduce patient discomfort (daily change of dressing).
5. Electrical burn (high voltage).
Disadvantages:
1.
2.
3.
4.
Blood loss.
Infection of excised wound.
Sacrifice of viable skin of partial thickness burn.
Risk of anesthesia.
Type of surgical intervention:
1. Non burn surgery e.g. tracheostomy, fracture fixation.
2. Esharotomy: circumferential burn and leathery eschar can be life
or limb threating it can cause decrease in the chest wall expansion,
and in extremities it act as tourniquet to blood and lymph flow
which in severe cases can lead to impaired blood supply. So
excised eschar (escharotomy) should done, which can be done
without anesthesia in patient room.
3. Fasciotomy: done especially in case of electrical burn.
4. Excision and wound debridement and covered by skin graft which
could be:
 Autograft Sheet graft.
Mesh graft.
Keratinocyte culture.
 Allograft Patient relatives.
 Xenograft Treated animal skin.
 Synthetic cover Hydrocolloid.
Local management:
1. Daily bathing with soap and water.
2. Local antibiotic agents:
 Mafenide acetate (Sulfamylon).
 Silver sulfadiazine(Flamazine)
 Povidon iodine.
3. Closed method: Occlusive dressing is applied over the topical agent
and usually changes twice daily.
Advanatages: Less pain and less heat loss.
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Disadvantages: potential increase in bacterial growth if the dressing is not
change twice daily. Especially when there is thick eschar closed method
is preferable.
Closed method particularly used for burn of extremities and hands.
4. Open method: In such method no dressing is applied over the wound
after application of topical antibiotics.
Avanatges: bacterial growth not enhanced as in closed method, and
wound remains visible.
Disadvanatges: increase pain and heat loss as result of exposed wound.
Especially used for burn in face, neck, trunk.
5. Eyes: protect cornea from dryness.
Ears: Suppurative chondritis prevented by avoiding pressure and usage
Antibiotics and driange.
Limbs: using splint, physiotherapy.
Prognosis:
1.
2.
3.
4.
5.
6.
Age of patient.
Burn surface area.
Burn depth.
Associated injuries.
Preexisting medical illness.
Early and effective management.
Graft:
Segment of tissue that removed from the body. It is completely
devascularised (i.e. contained no network of blood vessels).
Graft of any kind requires vascularization from the bed into which they
are placed for survival.
The donor site: is the site from which the graft is taken.
The recipient site: is the site where the graft is is apply.
Graft is divided according to sources:
 Autograft or homograft: from same individual.
 Allograft: from another individual of same species.
 Xenograft: from another species.
Graft is also divided according to its composition:
 Simple graft: contained single tissue type e.g. skin graft, bone
graft.
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 Composite graft: contained more than one kind of tissues e.g. nasal
septum graft which included mucosa and cartilage.
Skin graft:
A segment of variable thickness (according to type of skin graft) that
transfer from one site of body (donor site) to another site (recipient site).
Usually indicated for covering skin defect that can not close by primary
closure due to lack of the adjacent tissues for coverage.
Healthy, clean, well vascularised recipient site is needed for skin graft
survival.
Type of skin graft:
Divided into 2 kinds:
1. Full thickness skin graft: which consist of epidermis and full
thickness of dermis.
2. Split thickness skin graft: Which consist of epidermis and
variable portion of dermis, it described as thin, intermediate, and thick
according to thickness of included dermis.
Full thickness skin graft is usually taken with scalpel. While split
thickness skin graft is taken with especial instrument e.g. Humby knife,
Power driven dermatome.
Donor site of full thickness skin graft:
1.
2.
3.
4.
Postauricular skin.
Upper eyelid.
Supraclavicular skin.
Flexural skin: the antecubital fossa and groin.
Donor site of partial thickness of skin graft:
Any site can be used. But most commonly donor sites are:
1. The thigh and the upper limb.
2. The flexor aspect of the forearm.
3. The whole of reasonable plane of torso.
4. Other aspect of the forearm and lower leg, these site usually used
when above areas not available.
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Meshed versus sheet skin graft:
Multiple mechanical incisions result in meshed skin graft which
immediate expansion of the graft, also allow drainage of collection like
seroma.hematoma through numerous holes. Mesh graft result in "pebble"
appearances that is aesthetically unacceptable.
In contrast as sheet graft has continuous, uninterapted surface leading to
superior aesthetic result, but has disadvantage of not allowing serum and
blood to drain and need for larger skin graft.
Contraindication of skin graft:
1.
2.
3.
4.
5.
6.
Deadly, heavy contaminated wound.
Area of poor vascular supply.
Tendon denuded of paratenon.
Muscle denuded of epimysium.
Cartilage denuded of perichondrium.
Bone denuded of periosteum.
Full thickness skin graft
split thickness skin graft
1. Donor site should closed directly,
1.Donor site healed
Since no epithelium appendage remain
spontaneously.
For resurfacing.
2. Intake less readily.
2. Good intake.
3. Undergo less 2ndry contraction.
3. Have more 2ndry
Contraction.
4. Have better cosmetic result in
Regarding texture.
4. Less cosmetic result in
Compare to full thickness S.G
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Cultured skin graft:
Used for coverage of large defect when autologus skin is short supply for
extensive third degree burn.
In vitro cultivation and serial culturing of keratinocytes make production
of viable epithelium sheet possible. Cultured epithelium alone, however
dose not provides mechanically and aesthetically satisfactory long term
coverage.
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