What is multi organ dysfunction syndrome? Principles of management of ARDS in septic shock due to severe burn. [TU 2062]
Common causes of death in a burn patient. What is role of skin grafting in burn? Enumerate various type of type of free skin graft. [TU 2059]
Classify burn. Outline the management of flame burn of 55% in a lady of 60 kg. [TU 2066/1]
Causes of burn?
- Flame: damage from superheated, oxidized air
- Scald: damage from contact with hot liquids
- Contact: damage from contact with hot or cold solid materials
- Chemicals: contact with noxious chemicals
- Electricity: conduction of electrical current through tissues
Third degree burn. [TU 2069/1]
Depth of burn?
- First degree (confined to epidermis) : injury localized to the epidermis, painful and erythematous and blanch to the touch with an intact epidermal barrier
- Second degree (have some degree of dermal damage)
- Superficial second degree: injury to the epidermis and superficial dermis, erythematous and painful, blanch to touch, and often blister. wounds spontaneously re-epithelialize from retained epidermal structures in the rete ridges, hair follicles, and sweat glands in 1 to 2 weeks. After healing, these burns may have some slight skin discoloration in the long term
- Deep second degree: injury through the epidermis and deep into the dermis, involves reticular dermis appear more pale and mottled, do not blanch to touch, but remain painful to pinprick. These burns heal in 2 to 5 weeks by reepithelialization from hair follicles and sweat gland keratinocytes, often with severe scarring as a result of the loss of dermis.
- Third degree: full-thickness injury through the epidermis and dermis into subcutaneous fat, hard, leathery eschar that is painless and black, white, or cherry red. No epidermal or dermal appendages remain; thus, these wounds must heal by re-epithelialization from the wound edges. Deep dermal and fullthickness burns require excision with skin grafting from the patient to heal the wounds in a timely fashion.
- Fourth degree: injury through the skin and subcutaneous fat into underlying muscle or bone
Zones of injury after burn?
- Zone of coagulation - necrotic area of burn where cells have been disrupted is termed the. This tissue is irreversibly damaged at the time of injury
- Zone of stasis - area immediately surrounding the necrotic zone has a moderate degree of insult with decreased tissue perfusion. depending on the wound environment, can either survive or go on to coagulative necrosis. The zone of stasis is associated with vascular damage and vessel leakage
- Zone of hyperemia - characterized by vasodilation from inflammation surrounding the burn wound. This region contains the clearly viable tissue from which the healing process begins and is generally not at risk for further necrosis.
Assessment of burn size?
Rule of nine.
Berkow formula in children, Children have a relatively larger portion of the body surface area in the head and neck, which is compensated for by a relatively smaller surface area in the lower extremities. Infants have 21% of the TBSA in the head and neck and 13% in each leg, which incrementally approaches the adult proportions with increasing age
Pain management in burn?
- Small doses of intravenous morphine
- Intramuscular or subcutaneous narcotic injections for pain should never be used because drug absorption is decreased as a result of the peripheral vasoconstriction. This might become a problem later when the patient is resuscitated, and vasodilation increases absorption of the narcotic depot with resulting apnea.
Resuscitation formula for burn patients?
- Parkland - 4 mL/kg per % TBSA burn - colloid – None – Free water - None
- Brooke - 1.5 mL/kg per % TBSA burn – Colloid - 0.5 mL/kg per % TBSA burn – Free water - 2 L
- Galveston (pediatric) - 5000 mL/m2 burned area + 1500 mL/m2 total area –Colloid - None – Free water – None
- All of the formulas listed in Table 19-2 calculate the amount of volume given in the first 24 hours, half of which is given in the first 8 hours.
Tetanus prophylaxis in burn?
- All patients with burns of more than 10% TBSA should receive 0.5 mL of tetanus toxoid.
- If prior immunization is absent or unclear or the last booster dose was more than 10 years ago, 250 units of tetanus immune globulin are also given.
Indication and technique of Escharotomies?
- Indication - When deep second- and third-degree burn wounds encompass the circumference of an extremity, peripheral circulation to the limb can be compromised
- Technique - incision of the lateral and medial aspects of the extremity with a scalpel or electrocautery
- unit. The entire constricting eschar must be incised longitudinally to completely relieve the impediment to blood flow. The incisions are carried down onto the thenar and hypothenar eminences and along the dorsolateral sides of the digits to completely open the hand, if it is involved. For chest, incision along the sternum along with subcostal incision bilaterally.
- If distal perfusion does not improve with these measures, central hypotension from hypovolemia should be suspected and treated
Short note on Inhalation Burns. [TU 2070]
Management of inhalation injury?
- Bronchodilators (Albuterol) - q2h
- Nebulized heparin - 5000-10,000 units with 3 mL normal saline q4h
- Nebulized acetylcysteine - 20%, 3 mL q4h
- Hypertonic saline - Induces effective coughing
- Racemic epinephrine - Reduces mucosal edema
Clinical indication for intubation?
- PaO2 - <60 mm/hg, PaCO2 - >50 mm Hg (acutely)
- PaO2/FIO2 ratio - <200
- Respiratory or ventilatory failure - Impending
- Upper airway edema - Severe
Wound care in burn patients?
- These wounds require no dressing and are treated with topical salves to decrease pain and to keep
- the skin moist.
- Second-degree wounds can be treated with daily dressing changes with topical antibiotics, cotton gauze, and elastic wraps.
- Deep second-degree and third-degree wounds require excision and grafting for sizable burns, and the choice of initial dressing should be aimed at holding bacterial proliferation in check and providing occlusion until the operation is performed.
Antimicrobials for burn?
- Two classes: salves and soaks.
- Salves are generally applied directly to the wound with cotton dressings placed over them. Salves may be
- applied once or twice a day but may lose their effectiveness between dressing changes. Frequent dressing changes can result in shearing with loss of grafts or underlying healing cells.
- Soaks are generally poured into cotton dressings on the wound. Soaks remain effective because antibiotic solution can be added without removal of the dressing; however, the underlying skin can become macerated.
Examples of Salves and Soaks?
- Antimicrobial Salves
- Silver sulfadiazine (Silvadene) - Broad-spectrum antimicrobial; painless and easy to use; does not penetrate eschar; may leave black tattoos from silver ion; mild inhibition of epithelialization
- Mafenide acetate (Sulfamylon) - Broad-spectrum antimicrobial; penetrates eschar; may cause pain in sensate skin; wide application may cause metabolic acidosis; mild inhibition of epithelialization
- Bacitracin - Ease of application; painless; antimicrobial spectrum not as wide as above agents
- Neomycin - Ease of application; painless; antimicrobial spectrum not as wide
- Polymyxin B - Ease of application; painless; antimicrobial spectrum not as wide
- Antimicrobial Soaks
- 0.5% Silver nitrate - Effective against all microorganisms; stains contacted areas; leaches sodium from wounds; may cause methemoglobinemia
- 5% Mafenide acetate - Wide antibacterial coverage; no fungal coverage; painful on application to sensate wound; wide application associated with metabolic acidosis
A method used to estimate an individual's basal metabolic rate (BMR) and daily kilocalorie requirements
Nutrition required in burn?
- Curreri formula (kcal/day) - specific for burns, may significantly overestimate energy requirements, maximum 50% BSA of burn
- Age 16–59 years: (25)W + (40)TBSA
- Age 60+ years: (20)W + (65)TBSA
- Sutherland formula
- Children: 60 kcal/kg + 35 kcal%TBSA
- Adults: 20 kcal/kg + 70 kcal%TBSA
- Protein needs
- Greatest nitrogen losses between days 5 and 10
- 20% of kilocalories should be provided by proteins
- Davies formula
- Children: 3 g/kg + 1 g%TBSA
- Adults: 1 g/kg + 3 g%TBSA
Harris-Benedicts formula - for adults
Galveston formula - for infants
Describe the pathophysiology and management of electric burn. [TU 2067/2]
Short note on High voltage electric burns. [TU 2062]
What are the principles of management of high voltage electric injury? How will you deal with a patient of high voltage electric injury of his upper limb? [TU 2073]
Short note on Electric Burn. [TU 2071,68/2]
Pathophysiology of electrical burn?
- Electrical current enters a part of the body, such as the fingers or hand, and proceeds through tissues
- with the lowest resistance to current, generally the nerves, blood vessels, and muscles. The skin has a relatively high resistance to electrical current and is therefore mostly spared. The current then leaves the body at a “grounded” area, typically the foot. Heat generated by the transfer of electrical current and passage of the current itself then injures the tissues. During this exchange, the muscle is the major tissue through which the current flows, and
- thus it sustains the most damage Blood vessels transmitting much of the electricity initially remain patent, but they may proceed to progressive thrombosis as the cells either die or repair themselves, thus resulting in further tissue loss from ischemia.
- Patients with electrical injuries are at risk for other injuries, such as being thrown from the electrical jolt or falling from heights after disengaging from the electrical current. In addition, the violent tetanic muscle contractions that result from alternating current sources may cause a variety of fractures and dislocations.
Management of electrical burn?
- If the muscle compartment is extensively injured and necrotic, such that the prospects for eventual function are dismal, early amputation may be necessary. We advocate early exploration of affected muscle beds and débridement of devitalized tissues.
- Fasciotomies should be complete and may require nerve decompressions, such as carpal tunnel and Guyon canal releases.
- Vigorous hydration and infusion of intravenous sodium bicarbonate (5% continuous infusion) and mannitol (25 g every 6 hours for adults) Urine output should be maintained at 2 mL/kg/hr.
Note- Guyon canal (ulnar canal) - contains ulnar artery and ulnar nerve
Indication of bicarbonate in electric burn?
- Severe rhabdomyolysis, such as those with a
- - serum CK above 5000 unit/L or
- - clinical evidence of severe muscle injury (eg, crush injury) and
- - rising serum CK, regardless of the initial value.
- In such patients, bicarbonate may be given, providing the following conditions are met:
- ●Severe hypocalcemia is not present
- ●Arterial pH is less than 7.5
- ●Serum bicarbonate is less 30 mEq/L
Long term effects of electric burn?
- Central nervous system effects, such as cortical encephalopathy, hemiplegia, aphasia, and brainstem dysfunction injury,
- Development of cataracts, which can be delayed for several years
Mechanism of alkali and acid burn?
- There are three factors involved in the mechanism of alkali burns:
- (1) saponification of fat causes the loss of insulation of heat formed in the chemical reaction with tissue;
- (2) massive extraction of water from cells causes damage because of the hygroscopic nature of alkali; and
- (3) alkalis dissolve and unite with the proteins of the tissues to form alkaline proteinates, which are soluble and contain hydroxideions. These ions induce further chemical reactions, penetrating deeper into the tissue.
Acids induce protein breakdown by hydrolysis, which results in a hard eschar that does not penetrate as deeply as that caused by the alkalis.
Management of acid and alkali burn?
Irrigate copiously with water (several liters) - Check surface pH
For acid burn - If <7, continue irrigating until pHreaches the physiologic range(7–7.5). Take care to direct the irrigant away from noninjured skin.Once wound pH reaches a physiologic range, the injury process has finished.
For alkali burn - If >7.5, continue irrigatinguntil pH reaches thephysiologic range (7–7.5).pH should be checked again after débridement because alkali agents can penetrate through the surface. Thereafter, treat thewound with standard techniques
Features of formic acid injury?
Electrolyte abnormalities are of great concern for patients who have sustained extensive formic acid injuries, with metabolic acidosis, renal failure, intravascular hemolysis, and pulmonary complications (acute respiratory distress syndrome) being common.
Features of Hydrofluoric acid injury?
- Hydrofluoric acid produces dehydration and corrosion of tissue with free hydrogen ions. In addition, the fluoride ion complexes with bivalent cations such as calcium and magnesium to form insoluble salts. Systemic absorption of the fluoride ion then can induce intravascular calcium chelation and hypocalcemia, which causes life-threatening arrhythmias. Beyond initial copious irrigation with clean water, the burned area should be treated immediately with copious 2.5% calcium gluconate gel. These wounds in general are extremely painful because of the calcium chelation and associated potassium release. This finding can be used to determine the effectiveness of treatment. The gel should be changed at 15-minute intervals until the pain subsides, an indication of removal of the active fluoride ion. If pain relief is incomplete after several applications or if symptoms recur, intradermal injections of 10% calcium gluconate (0.5 mL/cm2 affected), intra-arterial calcium gluconate into the affected extremity, or both may be required to alleviate symptoms
- All patients with hydrofluoric acid burns should be admitted for cardiac monitoring, with particular attention paid to prolongation of the QT interval
Short note on skin bank? [TU 2072/4]
- Skin Banking is a process in which skin is removed from a donor body, tested for suitability as a graft material, packaged, stored, and finally reused as a graft. The process is similar to that for blood banking. Skin grafts can be autografts or allografts.
- An autograft is tissue which is removed from and then used on the same individual.
- Allografts are tissue that is removed from one individual and used on a different individual.
- Allograft skin is used as a temporary burn wound graft and will be rejected by the recipient, usually within 7-21 days. Until rejection, however, allograft skin will provide many of the functions of healthy skin. Skin allografts will close a wound providing a barrier against infection and fluid loss, decrease pain, and promote healing of underlying tissues. Skin allografts are use as a transitional treatment until autografting can permanently close the burn wound. Allograft skin is obtained from cadaveric (deceased) donors after consent is obtained from the next-of-kin.
- Allograft skin may be used fresh or frozen. Fresh skin allografts are considered by some to be more desirable because they are more viable (alive) than frozen grafts. Others feel that viability is unimportant because the grafts are only temporary.
- Glycerol 85%