Chapter 21: Burns

Thermal injuries result from flame or scalding with severity proportional to exposure duration, while chemical burns from alkalis cause particularly destructive liquefaction necrosis. Electrical injuries convert energy to deep tissue heat that may not be immediately visible, and inhalation injuries involve toxic gases such as carbon monoxide, which binds to hemoglobin with extraordinary affinity. Burn severity is classified by depth, ranging from superficial first-degree burns to full-thickness injuries that destroy all skin layers and require grafting. The concept of burn zones explains how tissue destruction extends beyond the initial injury site, with the zone of coagulation representing irreversible damage while the surrounding zone of stasis may be salvaged through appropriate intervention. The Rule of Nines and Lund and Browder chart provide standardized methods for estimating total body surface area involvement. Major burns trigger a severe systemic inflammatory cascade resulting in burn shock, characterized by massive fluid shifts into interstitial spaces due to increased capillary permeability. This pathophysiologic state produces profound cardiovascular compromise, marked hypermetabolism that can persist for extended periods, and multiple organ dysfunction including acute kidney injury risk and stress ulcer formation. Management occurs across three distinct temporal phases: the resuscitative phase prioritizes airway management and fluid restoration using the Parkland formula with careful titration to maintain appropriate urine output, the acute phase emphasizes wound care with topical antimicrobials and surgical grafting using autografts, and the rehabilitative phase focuses on functional restoration and psychosocial recovery. Critical collaborative interventions include pain management with intravenous morphine due to unreliable absorption through alternative routes, aggressive nutritional support to meet extreme caloric demands, meticulous infection prevention given the compromised skin barrier, and specialized procedures such as escharotomy for circumferential burns. Electrical injuries require heightened vigilance for rhabdomyolysis with aggressive urinary output monitoring.