Burn injuries disrupt the skin barrier, leading to immediate tissue destruction and a complex systemic cascade. Thermal energy denatures cellular proteins, causing cell death in the zone of coagulation. Surrounding this is the zone of stasis, where tissue perfusion is compromised but potentially salvageable, and the zone of hyperaemia, which typically recovers fully.
Burns are classified by depth to guide treatment and predict healing outcomes:
Accurate calculation of Total Body Surface Area (TBSA) affected by partial and full-thickness burns is vital for fluid resuscitation formulas. The Rule of Nines provides a rapid clinical estimate for adults by dividing the body into regions roughly equivalent to 9% or multiples of 9%:
| Body Region | Adult Percentage | Description |
|---|---|---|
| Head and Neck | 9% | Entire head and neck area |
| Anterior Trunk | 18% | Chest and abdomen |
| Posterior Trunk | 18% | Upper and lower back |
| Each Upper Limb | 9% | Entire arm from shoulder to hand |
| Each Lower Limb | 18% | Entire leg from hip to foot |
| Perineum / Genitalia | 1% | Groin area |
For irregular or scattered burns, the patient's palm, including the fingers, represents approximately 1% of their TBSA and can serve as a quick gauge.
Major burns exceeding 20% TBSA trigger a massive systemic inflammatory response. Capillary permeability increases dramatically across the entire body, not just at the burn site. Fluid shifts rapidly from the intravascular space into the interstitial spaces, resulting in severe generalized edema, hypovolemia, and a distinct form of distributive and hypovolemic shock known as burn shock.
Myocardial contractility decreases early on, compounding the drop in cardiac output. Simultaneously, the metabolic rate skyrockets into a hypermetabolic state driven by stress hormone release. Renal and gastrointestinal blood flow plummets as the body prioritizes perfusion to the brain and heart, placing the patient at immediate risk for acute kidney injury and paralytic ileus.
Initial care prioritizes stopping the burning process and stabilizing life-threatening trauma following standard ABCDE protocols. First responders must remove the heat source, extinguish flames, and cool the skin with cool—never ice-cold—water to prevent further tissue damage.
Airway management is critical, especially if facial burns, singed nasal hairs, or carbonaceous sputum indicate inhalation injury. Upper airway edema can develop rapidly, requiring early endotracheal intubation. Large-bore intravenous lines are secured immediately, bypassing burned skin sites if possible, to prepare for aggressive fluid resuscitation.
Formula-driven fluid resuscitation prevents profound shock in patients with significant burns. The Parkland formula is widely utilized, calculating crystalloid requirements over the first 24 hours post-injury:
Monitoring the adequacy of resuscitation relies heavily on urine output rather than blood pressure alone. Nurses titrate the intravenous infusion rate to maintain an adult urine output between 0.5 to 1.0 mL/kg/hour, ensuring adequate organ perfusion without causing fluid overload or pulmonary edema.
Burn wound management aims to prevent infection, promote re-epithelialization, and prepare the bed for surgical closure. Regular cleansing with mild soap and water removes exudate and loose necrotic tissue. Debridement—either mechanical, enzymatic, or surgical—removes non-viable eschar that serves as a breeding ground for bacteria.
For deep partial and full-thickness burns, early excision of dead tissue followed by skin grafting is standard practice. Autografts, using the patient's own healthy skin, provide permanent closure. When donor sites are limited, temporary biological dressings or synthetic substitutes protect the wound bed and reduce systemic fluid loss until autografting is feasible.
Major burns provoke a hypermetabolic and hypercatabolic state that can persist for months, consuming lean body mass and severely delaying wound healing. Caloric and protein requirements escalate dramatically to fuel immune function and tissue regeneration.
Early enteral nutrition via a small-bore nasoenteric tube protects the gut mucosal barrier, prevents stress ulcers (Curling's ulcers), and blunts the hypermetabolic response. High-protein diets, vitamin supplementation, and blood glucose control are standard components of metabolic care designed to combat massive catabolism and muscle wasting.
Infection remains the leading cause of morbidity and mortality in severe burn survivors. Loss of the skin barrier, coupled with burn-induced immunosuppression, allows microorganisms to colonize wounds easily and progress to invasive sepsis.
除了 wound infections, circumferential burns on the limbs or chest can act like a tourniquet as edema forms underneath, compromising distal circulation or restricting chest wall expansion. Nurses monitor pulses, capillary refill, and respiratory mechanics closely, recognizing that surgical escharotomy may be required to release constrictive pressure and restore blood flow or ventilation.