# Seminar 15: Burn Surgery ## General Surgery Clerkship - Unit 15 --- ## Learning Objectives By the end of this seminar, students will be able to: 1. Classify burn injuries by depth and extent using appropriate assessment tools including the rule of nines and Lund-Browder chart 2. Apply initial assessment principles including recognition of inhalation injury and carbon monoxide poisoning 3. Calculate fluid resuscitation requirements using the Parkland formula and titrate to appropriate physiologic endpoints 4. Recognize indications for and perform escharotomy for circumferential burns compromising perfusion or ventilation 5. Describe surgical treatment principles including timing of excision, grafting techniques, and skin substitutes 6. Identify burn center referral criteria and apply principles of burn rehabilitation and long-term management --- ## Seminar Outline ### I. Burn Classification and Depth Assessment Burn injuries result from thermal, chemical, electrical, or radiation energy transfer to tissues, with severity determined by depth of tissue destruction, total body surface area involvement, and associated injuries including inhalation injury. Accurate assessment of burn depth guides treatment decisions from wound care to surgical intervention and provides prognostic information regarding healing potential and functional outcome. Modern burn classification has replaced the traditional first, second, and third degree nomenclature with descriptive terms based on anatomical depth of injury, though the older terminology persists in clinical practice and literature. Superficial burns involve only the epidermis and present as erythematous, dry, painful wounds without blistering, exemplified by typical sunburn. These injuries heal spontaneously within three to five days through epithelial regeneration from intact basal cells without scarring. Superficial partial-thickness burns extend through the epidermis into the papillary dermis, presenting as pink, moist wounds with blisters and intense pain due to exposed nerve endings. Intact hair follicles, sweat glands, and other dermal appendages provide epithelial cells for spontaneous healing within seven to fourteen days, typically without significant scarring if infection is prevented. Deep partial-thickness burns extend into the reticular dermis, destroying most dermal appendages while leaving some viable tissue for potential epithelial regeneration. These wounds appear pale or mottled with decreased moisture and diminished sensation due to partial nerve destruction. Healing occurs over two to four weeks if protected from infection and mechanical disruption, though spontaneous healing often produces hypertrophic scarring and may benefit from early excision and grafting. The clinical distinction between superficial and deep partial-thickness burns significantly impacts management decisions and outcomes. Full-thickness burns destroy the entire epidermis and dermis, extending into subcutaneous fat and potentially deeper structures. These wounds appear waxy, leathery, or charred with absent sensation and no blanching with pressure. Without epithelial appendages remaining, full-thickness burns cannot heal spontaneously except by wound contraction and epithelial migration from wound edges, an inadequate process for any significant wound size. Surgical excision and skin grafting are required for wound closure. Fourth-degree or subdermal burns extend beyond subcutaneous tissue into muscle, tendon, or bone, typically resulting from prolonged contact burns, high-voltage electrical injury, or severe flame burns. Panel A: Cross-sectional diagram showing burn depth classification from superficial through full-thickness with corresponding tissue layers, clinical appearance, and healing characteristics. Panel B: Clinical photographs comparing superficial partial-thickness burns with blistering and pink base versus deep partial-thickness with pale mottled appearance. Panel C: Full-thickness burn demonstrating waxy, leathery eschar without sensation or blanching. Panel D: Burn depth spectrum showing relationship between depth, healing time, pain sensation, and need for surgical intervention. --- ### II. Burn Extent Assessment and Severity Classification Assessment of total body surface area involvement is essential for fluid resuscitation calculations, severity classification, and determination of burn center referral criteria. The Rule of Nines provides a rapid estimation method for adults, dividing the body into regions representing approximately nine percent or multiples thereof. The head and each upper extremity account for nine percent, the anterior and posterior trunk each represent eighteen percent, each lower extremity accounts for eighteen percent, and the perineum represents one percent. This estimation provides sufficient accuracy for initial resuscitation calculations and triage decisions. The patient's palm, including the fingers, represents approximately one percent of total body surface area and provides a useful tool for estimating scattered or irregular burn distribution. For more accurate assessment, particularly in pediatric patients whose body proportions differ significantly from adults, the Lund and Browder chart provides age-adjusted percentages accounting for the relatively larger head and smaller lower extremities of infants and children. Documentation of burn extent should clearly distinguish areas of different burn depths, as only partial-thickness and full-thickness burns are included in total body surface area calculations for resuscitation purposes. Burn severity classification integrates burn depth, extent, and associated factors to guide disposition and treatment intensity. Minor burns include partial-thickness burns less than ten percent total body surface area in adults or less than five percent in children and elderly, full-thickness burns less than two percent, and burns not involving high-risk anatomic areas. Moderate burns encompass partial-thickness burns of ten to twenty percent, full-thickness burns of two to ten percent, and burns with complicating factors such as diabetes or extremes of age. Major burns include partial-thickness greater than twenty percent, full-thickness greater than ten percent, inhalation injury, high-voltage electrical injury, and burns involving face, hands, feet, genitalia, or major joints. Burn center referral criteria established by the American Burn Association identify patients who benefit from specialized burn care. Criteria include partial-thickness burns greater than ten percent total body surface area, burns involving face, hands, feet, genitalia, perineum, or major joints, full-thickness burns of any size, electrical burns including lightning injury, chemical burns with threat of functional or cosmetic impairment, inhalation injury, burns in patients with significant comorbidities, burns with associated trauma where burn injury poses greatest risk, and burns in children at hospitals without qualified personnel or equipment. Early transfer to a burn center optimizes outcomes for patients meeting these criteria. Panel A: Rule of Nines diagram for adults showing body region percentages with anterior and posterior views and comparison to pediatric proportions. Panel B: Lund and Browder chart demonstrating age-adjusted percentages for head and lower extremities from infant through adult. Panel C: Palm method illustration showing one percent body surface area estimation for scattered burns. Panel D: Burn severity classification table showing minor, moderate, and major criteria with corresponding disposition recommendations and burn center referral indications. --- ### III. Initial Assessment and Airway Management Initial assessment of burn patients follows standard trauma protocols with primary survey evaluation of airway, breathing, and circulation, recognizing that thermal injury may be accompanied by associated trauma particularly in explosion or motor vehicle incidents. Airway assessment assumes particular importance in burn patients due to the risk of inhalation injury causing rapid progression of upper airway edema that can render intubation impossible within hours. Clinical indicators of potential inhalation injury include burns sustained in enclosed space, facial burns with singed eyebrows or nasal hair, carbonaceous sputum, hoarseness or stridor, and hypoxia. The threshold for early intubation should be low when these findings are present. Upper airway thermal injury results from direct heat exposure and produces supraglottic edema that may progress to complete airway obstruction. The efficient heat exchange capacity of the upper airway typically protects the lower airways from direct thermal injury except with steam burns, which carry water vapor capable of delivering heat deep into the tracheobronchial tree. Lower airway and parenchymal injury result primarily from chemical irritation by combustion products including aldehydes, acrolein, and other toxic compounds that cause bronchospasm, mucosal sloughing, and inflammatory infiltrate progressing to acute respiratory distress syndrome. Carbon monoxide poisoning occurs frequently in enclosed-space fires and requires immediate recognition and treatment. Carbon monoxide binds hemoglobin with approximately 250 times the affinity of oxygen, producing carboxyhemoglobin that is incapable of oxygen transport. Standard pulse oximetry cannot distinguish carboxyhemoglobin from oxyhemoglobin, resulting in falsely normal oxygen saturation readings despite severe hypoxia. Symptoms progress from headache and confusion at carboxyhemoglobin levels of twenty to thirty percent to coma and death at higher levels. Treatment consists of immediate administration of one hundred percent oxygen, which accelerates carboxyhemoglobin dissociation, reducing half-life from approximately four hours on room air to sixty to ninety minutes. Hyperbaric oxygen therapy may be considered for severe poisoning. Cyanide toxicity should be suspected in patients with burns from synthetic materials who demonstrate lactic acidosis and altered mental status disproportionate to carboxyhemoglobin levels. Cyanide inhibits cytochrome oxidase, blocking cellular oxygen utilization and forcing anaerobic metabolism. Treatment with hydroxocobalamin, which chelates cyanide, should be administered empirically when clinical suspicion exists, as confirmatory testing is not rapidly available. The combination of carbon monoxide and cyanide poisoning creates synergistic toxicity more severe than either alone, underscoring the importance of early recognition and treatment of smoke inhalation injury. Panel A: Algorithm for airway assessment in burn patients showing clinical indicators of inhalation injury and threshold for early intubation. Panel B: Pathophysiology diagram of inhalation injury showing upper airway thermal injury, lower airway chemical injury, and parenchymal damage progression to ARDS. Panel C: Carbon monoxide poisoning mechanism showing hemoglobin binding, oxygen-hemoglobin dissociation curve shift, and treatment with supplemental oxygen. Panel D: Cyanide toxicity pathway illustrating cytochrome oxidase inhibition, lactic acidosis production, and hydroxocobalamin treatment mechanism. --- ### IV. Fluid Resuscitation Burn injuries produce profound systemic inflammatory response with massive capillary leak and fluid shifts from intravascular to interstitial compartments, resulting in hypovolemic shock if fluid losses are not replaced. The Parkland formula provides initial guidance for crystalloid resuscitation in burns greater than twenty percent total body surface area, calculating total twenty-four hour fluid requirement as four milliliters per kilogram body weight per percent total body surface area burned. Half of this calculated volume is administered in the first eight hours from the time of burn, with the remaining half over the subsequent sixteen hours. Lactated Ringer solution is the preferred crystalloid for burn resuscitation due to its physiologic electrolyte composition and reduced chloride content compared to normal saline. The formula provides a starting point for resuscitation that must be titrated to physiologic endpoints, primarily urine output of 0.5 to one milliliter per kilogram per hour in adults and one to 1.5 milliliters per kilogram per hour in children. Additional endpoints include normalizing heart rate, maintaining mean arterial pressure greater than sixty millimeters of mercury, clearing lactate, and improving base deficit. Resuscitation is an active process requiring frequent reassessment and adjustment rather than mechanical adherence to calculated volumes. Fluid creep describes the phenomenon of administering excessive crystalloid volumes beyond formula calculations, with potentially devastating consequences. Over-resuscitation leads to worsening tissue edema, impaired oxygen delivery, pulmonary edema with respiratory failure, and abdominal compartment syndrome. Modern burn resuscitation emphasizes titration to minimal effective volumes guided by physiologic endpoints. When resuscitation requirements significantly exceed formula predictions, reassessment should consider underestimation of burn extent, unrecognized associated injury, or need for colloid supplementation. Addition of albumin beginning at twelve to twenty-four hours may reduce total fluid requirements and improve resuscitation efficiency in large burns. Colloid administration typically begins on the second day of resuscitation after the initial capillary leak phase subsides. Five percent albumin at a dose of 0.3 to 0.5 milliliters per kilogram per percent total body surface area provides oncotic support and may reduce overall fluid requirements. Monitoring for adequate resuscitation extends beyond urine output to include clinical assessment of peripheral perfusion, trending of laboratory markers, and recognition of under- or over-resuscitation. The complexity of burn resuscitation underscores the importance of experienced burn center management for major injuries. Panel A: Parkland formula calculation demonstrating 4 mL x kg x %TBSA with example calculation and administration schedule over first 24 hours. Panel B: Titration endpoints including urine output targets, heart rate, mean arterial pressure, lactate, and base deficit with adjustment algorithm. Panel C: Fluid creep consequences illustrating pulmonary edema, tissue edema, and abdominal compartment syndrome from over-resuscitation. Panel D: Colloid addition timing and indications showing transition from pure crystalloid to albumin supplementation in the second resuscitation day. --- ### V. Wound Management and Escharotomy Initial wound care for burns focuses on preventing infection, protecting viable tissue, and preparing wounds for definitive management. Gentle cleaning with mild soap and water removes debris and loose tissue, with debridement of ruptured blisters while intact blisters may be left in place if not interfering with assessment or function. Cooling of acute burns with tap water provides pain relief and may limit burn progression if applied within minutes of injury, though ice should never be used due to risk of frostbite injury to compromised tissue. Tetanus prophylaxis should be updated if not current. Topical antimicrobial therapy prevents wound colonization and infection during the period before definitive wound closure. Silver sulfadiazine has been the most widely used topical agent, providing broad-spectrum coverage with good patient tolerability, though it should be avoided in patients with sulfa allergy and may cause transient leukopenia. Mafenide acetate penetrates eschar more effectively and is preferred for ear burns to prevent chondritis, but causes pain on application and systemic absorption can produce metabolic acidosis through carbonic anhydrase inhibition. Silver-impregnated dressings provide sustained antimicrobial release with less frequent dressing changes and may be preferable for outpatient management. Escharotomy is indicated for circumferential full-thickness burns of the extremities or trunk that compromise distal perfusion or ventilatory mechanics. Full-thickness burns produce inelastic eschar that cannot expand with tissue edema, creating a tourniquet effect on extremities and restrictive physiology on the chest. Assessment for extremity escharotomy includes evaluation of distal pulses, capillary refill, Doppler signals, and compartment pressures, with absent or diminished findings indicating need for release. Chest escharotomy is indicated when circumferential thoracic burns impair ventilation, manifesting as increased peak airway pressures in ventilated patients or respiratory distress in spontaneously breathing patients. Escharotomy technique involves incision through eschar into subcutaneous fat along the mid-lateral lines of extremities, avoiding major neurovascular structures. On the limb, incisions extend from proximal to distal along both medial and lateral aspects, with additional incisions across joints if needed. Digits require mid-lateral incisions on the ulnar border for the thumb and fingers two through four and the radial border of the fifth digit to avoid impairment of pinch function. Chest escharotomy employs bilateral anterior axillary line incisions connected across the upper chest and costal margins as needed. Minimal bleeding from escharotomy incisions through full-thickness burn confirms adequate depth, as viable tissue would bleed briskly. Panel A: Initial wound care protocol showing gentle cleansing, blister management, and cooling technique with contraindications for ice application. Panel B: Comparison of topical antimicrobial agents including silver sulfadiazine, mafenide acetate, and silver-impregnated dressings with advantages and disadvantages of each. Panel C: Escharotomy indications assessment showing evaluation of distal perfusion for extremity and ventilatory mechanics for chest with decision thresholds. Panel D: Escharotomy incision placement diagram demonstrating mid-lateral lines on extremities, bilateral anterior axillary chest incisions, and connecting incisions with depth through eschar to subcutaneous tissue. --- ### VI. Surgical Treatment Principles Early excision of burn eschar with immediate wound coverage has become the standard of care for deep partial-thickness and full-thickness burns, replacing the historical approach of allowing eschar separation over weeks. Studies comparing early excision within seventy-two hours to conservative management demonstrated reduced mortality, decreased hospital length of stay, and improved functional outcomes. The benefits derive from removal of devitalized tissue that serves as a culture medium for bacterial proliferation, reduction of systemic inflammatory response from the burn wound, and earlier wound closure with reduced scarring and contracture. Tangential excision involves serial shaving of thin layers of burn tissue using specialized knives until punctate bleeding indicates viable dermis or subcutaneous tissue. This technique preserves maximum viable tissue and is preferred for partial-thickness burns where dermal preservation improves cosmetic and functional outcomes. Fascial excision removes all tissue down to fascia in a single pass, providing a more reliable vascular bed for grafting but at the cost of worse cosmetic appearance. Fascial excision is reserved for very deep burns, limited resources where multiple excisional procedures are not feasible, or extensive burns where time efficiency is paramount. Blood loss during burn excision is substantial, averaging approximately one hundred milliliters per percent body surface area excised, and may be reduced through topical epinephrine application, subcutaneous injection of dilute epinephrine solution, tourniquet use on extremities, and limiting excision to ten to twenty percent total body surface area per operative session. Planning for blood product availability before excisional surgery is essential, with packed red blood cells and fresh frozen plasma typically required. Hypothermia during burn surgery poses significant risk and demands aggressive warming measures including elevated operating room temperature, warming blankets, fluid warmers, and minimizing exposure time. Skin grafting provides definitive wound coverage following excision. Split-thickness skin grafts harvested from unburned donor sites with a dermatome include epidermis and partial dermis, with typical thickness of 0.010 to 0.015 inches. Meshing the graft creates a pattern of slits allowing expansion up to three-fold, increasing coverage from limited donor sites and permitting fluid drainage from beneath the graft. Sheet grafts without meshing provide superior cosmetic results and are preferred for visible areas including the face and hands. Graft take depends on adherence to vascularized wound bed, requiring prevention of hematoma, seroma, and shear through appropriate bolster dressings and immobilization. Panel A: Early excision versus conservative management comparison showing timeline, infection risk, hospital stay, and outcome differences. Panel B: Tangential excision technique demonstrating serial passes with Goulian or Watson knife until punctate bleeding indicates viable tissue. Panel C: Blood loss management strategies including topical epinephrine, tourniquet use, and staging of extensive excisions with blood product preparation. Panel D: Split-thickness skin graft harvest showing dermatome use, meshing technique with expansion ratios, and sheet graft application for facial burns. --- ### VII. Skin Substitutes and Advanced Wound Coverage When autograft donor sites are insufficient for extensive burns, temporary wound coverage maintains wound protection and physiologic stability until donor sites regenerate for reharvest or definitive coverage becomes available. Cadaveric allograft provides excellent temporary coverage that vascularizes and adheres to the wound bed, reducing evaporative losses and pain while preventing desiccation and infection. Eventually the allograft is rejected and must be removed and replaced with autograft, but it serves as a valuable bridge in massive burns. Xenograft from porcine sources provides similar temporary coverage at lower cost but with less optimal adherence compared to allograft. Biosynthetic skin substitutes have been developed to address limitations of cadaveric allograft including availability, disease transmission risk, and eventual rejection. Biobrane consists of a nylon mesh embedded in silicone bonded to collagen and is particularly useful for superficial partial-thickness burns and donor sites, providing pain relief and promoting epithelialization without need for removal. Integra bilayer wound matrix consists of bovine collagen and glycosaminoglycan covered by temporary silicone epidermis, which integrates with the wound to form a neodermis that is subsequently covered with thin autograft after silicone removal. This approach is valuable for deep burns where dermal preservation would otherwise be impossible. Cultured epithelial autografts address the challenge of wound coverage in massive burns where donor sites are severely limited. The patient's keratinocytes are harvested from a small biopsy and expanded in tissue culture over approximately three weeks to produce sheets of epithelium that can cover extensive wounds. The cultured cells lack dermis and are fragile with high failure rates compared to conventional autograft, but provide a life-saving option when alternatives are exhausted. Newer technologies including spray-on skin cell suspensions offer faster preparation and application but similarly lack dermal components. Negative pressure wound therapy has become an important adjunct for managing complex burn wounds. Applied over skin grafts, it provides uniform contact between graft and wound bed, removes fluid collections that would prevent graft take, and reduces shear forces. For burns not ready for grafting, negative pressure therapy promotes granulation tissue formation and reduces bacterial burden. The therapy is particularly valuable for burns over irregular contours, in anatomically challenging locations, and in patients where immobilization for graft protection is difficult. Dressing changes every forty-eight to seventy-two hours allow wound assessment while maintaining therapeutic benefit. Panel A: Temporary wound coverage options comparing allograft, xenograft, and biosynthetic materials with advantages, disadvantages, and appropriate clinical scenarios. Panel B: Integra application technique showing bilayer structure, vascularization process, silicone removal timing, and thin autograft application. Panel C: Cultured epithelial autograft process from biopsy harvest through tissue culture expansion to sheet application with timeline and limitations. Panel D: Negative pressure wound therapy over skin grafts demonstrating mechanism of action, dressing components, and clinical benefits for graft take. --- ### VIII. Burn Complications and Infection Burn wound infection represents the leading cause of death in patients surviving initial resuscitation, reflecting the loss of skin barrier function and immunosuppression accompanying major thermal injury. The burn wound provides an ideal environment for bacterial proliferation with abundant devitalized tissue, warm moist conditions, and impaired local and systemic immunity. Progression from colonization to invasive infection may be rapid, with organisms penetrating through eschar into viable tissue and potentially disseminating systemically. Common pathogens include Staphylococcus aureus including methicillin-resistant strains, Pseudomonas aeruginosa, and other gram-negative organisms, with fungal infection an increasing concern in prolonged hospitalizations. Clinical signs of burn wound infection include wound discoloration with green, blue, or black changes, rapid eschar separation, conversion of partial-thickness to full-thickness injury, perilesional erythema and edema, and systemic manifestations including fever, altered mental status, and hemodynamic instability. Definitive diagnosis requires quantitative wound biopsy demonstrating greater than one hundred thousand organisms per gram of tissue or histologic evidence of microbial invasion into viable tissue. Management of burn wound infection includes systemic antibiotics guided by culture results, conversion from topical agents to mafenide acetate for better eschar penetration, and aggressive surgical excision of infected tissue. Hypertrophic scarring and contracture represent major long-term complications affecting function and appearance. Risk factors for hypertrophic scar formation include deep burns, delayed healing beyond two to three weeks, dark skin, young age, and wounds crossing joints or natural tension lines. Prevention through early wound closure remains the primary strategy, with pressure garments, silicone sheeting, and massage initiated after wound closure to modulate scar formation. Once established, hypertrophic scars may be treated with intralesional corticosteroid injection, laser therapy, or surgical revision with tissue rearrangement. Contractures limiting joint motion require surgical release with skin grafting or flap coverage. Additional complications of burn injury include Marjolin ulcer, a squamous cell carcinoma arising in chronic burn scars or unstable wounds years after injury, requiring wide excision and close follow-up. Heterotopic ossification may develop around joints, particularly the elbow, limiting range of motion and potentially requiring surgical excision if conservative management fails. Neuropathy affecting both motor and sensory function may result from direct thermal injury to nerves, compartment syndrome, or positioning injury during prolonged critical illness. Psychological sequelae including post-traumatic stress disorder, depression, anxiety, and body image disturbance affect the majority of major burn survivors and require integrated psychological support throughout the recovery process. Panel A: Burn wound infection progression from colonization through invasive infection with clinical signs at each stage and diagnostic criteria. Panel B: Management algorithm for burn wound infection showing systemic antibiotics, topical therapy changes, and surgical excision indications. Panel C: Hypertrophic scar and contracture formation with risk factors, prevention strategies, and treatment options including pressure garments and surgical release. Panel D: Long-term complications overview including Marjolin ulcer, heterotopic ossification, neuropathy, and psychological sequelae with management principles. --- ### IX. Metabolic Response and Nutritional Support Major burn injury produces the most profound hypermetabolic response of any form of trauma, with metabolic rate potentially exceeding two hundred percent of normal in extensive burns. The response begins after initial resuscitation in the ebb phase and persists for months to years, characterized by catabolism of skeletal muscle, accelerated gluconeogenesis, lipolysis, and negative nitrogen balance. This hypermetabolism contributes to muscle wasting, impaired wound healing, immune dysfunction, and multiorgan failure if not adequately supported. Understanding and modulating this response is essential for optimizing outcomes in major burn injury. Nutritional support must begin early and provide calories and protein sufficient to meet dramatically elevated demands. Calculation of caloric requirements uses predictive equations such as the Curreri formula or indirect calorimetry measurement of actual energy expenditure. Protein requirements reach 1.5 to two grams per kilogram per day to support wound healing and minimize muscle catabolism. Enteral nutrition is strongly preferred over parenteral nutrition due to maintenance of gut barrier function, reduced infectious complications, and lower cost. Feeding should begin within twenty-four hours of injury, typically through nasoenteric tube, with continuous infusion to maximize tolerance. Pharmacologic modulation of the hypermetabolic response provides additional benefit beyond nutritional support alone. Propranolol, a non-selective beta-blocker, attenuates the hyperdynamic cardiovascular response and reduces muscle protein catabolism, with pediatric studies demonstrating improved lean body mass preservation. Oxandrolone, an anabolic steroid, promotes protein synthesis and has been shown to reduce weight loss, increase lean body mass, and improve wound healing in burn patients. Insulin therapy beyond glycemic control may provide anabolic benefits, though hypoglycemia risk requires careful monitoring. Growth hormone, while anabolic, has been associated with increased mortality in critically ill patients and is not currently recommended. Thermoregulation is profoundly impaired in burn patients due to loss of skin barrier, evaporative water loss, and hypothalamic thermoregulatory dysfunction. Patients become obligate heat losers unable to maintain core temperature without environmental support. Operating room and patient care environments should be maintained at elevated temperatures of thirty to thirty-five degrees Celsius to reduce metabolic demands for thermogenesis. Warming blankets, radiant heaters, and warmed intravenous fluids help maintain normothermia. Hypothermia exacerbates coagulopathy, impairs immune function, and increases oxygen consumption through shivering, making temperature maintenance a priority throughout burn care. Panel A: Hypermetabolic response timeline showing ebb and flow phases with metabolic rate changes and clinical consequences of catabolism. Panel B: Nutritional support calculation using Curreri formula with protein requirements and preference for enteral over parenteral nutrition. Panel C: Pharmacologic modulation options including propranolol mechanism, oxandrolone anabolic effects, and insulin therapy with evidence summary. Panel D: Thermoregulation strategies showing environmental temperature targets, warming devices, and consequences of hypothermia in burn patients. --- ### X. Special Burns and Rehabilitation Electrical burns produce injury patterns distinct from thermal burns due to current passage through tissues with preferential flow along nerves and blood vessels. External wounds may dramatically underestimate internal injury, with extensive muscle necrosis beneath small entrance and exit wounds. High-voltage electrical injury, defined as greater than one thousand volts, produces the most severe injuries with risks of cardiac arrhythmia requiring monitoring, rhabdomyolysis with myoglobinuria requiring aggressive fluid resuscitation to maintain renal function, and compartment syndrome requiring early fasciotomy. Associated traumatic injuries from falls or tetanic muscle contraction must be systematically evaluated. Chemical burns require immediate copious water irrigation to dilute and remove the offending agent, with duration of at least fifteen to thirty minutes for most chemicals and continued until tissue pH normalizes. Attempts to neutralize acids with bases or vice versa are contraindicated as the exothermic neutralization reaction causes additional thermal injury. Specific antidotes exist for some chemical exposures, notably calcium gluconate gel for hydrofluoric acid burns which chelates fluoride ions and prevents systemic hypocalcemia. Alkali burns are particularly concerning as they produce liquefactive necrosis allowing deeper penetration compared to the coagulative necrosis of acid burns. Tar and asphalt burns occur in occupational settings and require specific management. The adherent material should first be cooled with water to prevent ongoing thermal injury, then removed with petroleum-based solvents that dissolve the tar without further tissue damage. Forcible removal risks additional mechanical injury to underlying tissue. Once the tar is removed, the underlying burn is managed according to standard principles based on depth assessment. Frostbite, while caused by cold rather than heat, produces similar tissue injury and is managed with rapid rewarming in warm water at approximately forty degrees Celsius, avoiding friction and preventing refreezing which causes additional damage. Burn rehabilitation begins during acute care and continues for years following injury, addressing physical function, scar management, and psychosocial adjustment. Early range of motion exercises maintain joint mobility and prevent contracture development. Positioning protocols place joints in anti-contracture positions, typically joint extension and abduction. Custom splinting maintains position during rest periods and protects healing grafts. Following wound closure, pressure garments provide continuous pressure to modulate scar maturation, worn continuously for twelve to twenty-four months until scars mature. Integration of physical therapy, occupational therapy, and psychological support optimizes functional and quality of life outcomes following burn injury. Panel A: Electrical burn pathophysiology showing current path through tissues, internal injury exceeding external wounds, and associated complications including cardiac, renal, and compartment syndrome. Panel B: Chemical burn management with irrigation protocol, pH monitoring, and specific antidotes including calcium gluconate for hydrofluoric acid. Panel C: Tar burn removal technique demonstrating cooling, petroleum-based solvent application, and subsequent depth assessment. Panel D: Rehabilitation continuum from acute range of motion through splinting, pressure garments, and long-term scar management with timeline. --- ## Summary - Burn depth classification ranges from superficial involving only epidermis through full-thickness destroying entire dermis, with depth determining healing potential and need for surgical intervention - Total body surface area assessment using Rule of Nines or Lund-Browder chart is essential for fluid resuscitation calculation and severity classification - Inhalation injury indicators including enclosed space exposure, facial burns, carbonaceous sputum, and stridor warrant low threshold for early intubation - Carbon monoxide poisoning causes falsely normal pulse oximetry with treatment being one hundred percent oxygen to accelerate carboxyhemoglobin dissociation - Parkland formula provides initial fluid resuscitation guidance of 4 mL x kg x %TBSA with half in first eight hours, titrated to urine output of 0.5 to 1 mL/kg/hr - Escharotomy is indicated for circumferential full-thickness burns compromising extremity perfusion or chest wall ventilatory mechanics - Early excision within seventy-two hours with skin grafting has replaced conservative management as standard of care for deep burns - Burn wound infection is the leading cause of death in resuscitated patients, requiring vigilant surveillance and aggressive surgical management - Hypermetabolic response reaches two hundred percent of normal requiring aggressive nutritional support with early enteral feeding - Burn center referral criteria include partial-thickness greater than ten percent, full-thickness any size, inhalation injury, and burns of face, hands, feet, or genitalia --- ## Key Terms | Term | Definition | |------|------------| | TBSA | Total body surface area involved with burn injury, assessed using Rule of Nines or Lund-Browder chart | | Parkland formula | Fluid resuscitation calculation for burns: 4 mL x kg body weight x %TBSA burned over 24 hours | | Escharotomy | Incision through burn eschar into subcutaneous tissue to release constriction from circumferential full-thickness burns | | Tangential excision | Surgical technique removing thin layers of burn tissue until punctate bleeding indicates viable dermis | | Split-thickness skin graft | Graft including epidermis and partial dermis used for burn wound coverage | | Carboxyhemoglobin | Hemoglobin bound to carbon monoxide, incapable of oxygen transport, causing tissue hypoxia | | Inhalation injury | Airway and pulmonary injury from inhaled smoke and combustion products, doubling mortality for given %TBSA | | Hypertrophic scar | Raised scar remaining within original wound boundaries, common complication of burn healing | | Fluid creep | Over-resuscitation with crystalloid leading to complications including pulmonary edema and abdominal compartment syndrome | | Integra | Bilayer dermal regeneration template consisting of bovine collagen and glycosaminoglycan with silicone epidermis | --- *This content is subject to the [MIT License](https://opensource.org/licenses/MIT). © 2024–2026 Hibbert School of Medicine.*