A 32-year-old man is brought to the emergency department 2 hours after sustaining a 40% total body surface area (TBSA) deep partial-thickness burn to his trunk and bilateral lower limbs from a house fire. He is alert, breathing spontaneously at 24/min, and has singed nasal hairs. His radial pulse is 118/min and blood pressure is 110/70 mmHg. Urine output is not yet documented. What is the most appropriate immediate next step in management?

Explanation

## Clinical Context This patient has a significant thermal injury (40% TBSA, deep partial-thickness) with signs of inhalation injury (singed nasal hairs, tachypnea). He is currently hemodynamically stable but at imminent risk of hypovolemic shock from massive fluid shifts into the interstitium. ## Pathophysiology of Burn Shock **Key Point:** Burn shock develops within minutes to hours of injury due to: 1. Increased capillary permeability from inflammatory mediators (histamine, prostaglandins, cytokines) 2. Massive fluid extravasation into the interstitium ("third space") 3. Loss of plasma volume without proportional loss of RBCs → hemoconcentration 4. This occurs even before significant evaporative losses ## Why Parkland Formula Now? **High-Yield:** The Parkland formula is the gold standard for initial fluid resuscitation in burns ≥20% TBSA: $$\text{Fluid (mL)} = 4 \times \text{TBSA (\%)} \times \text{Body weight (kg)}$$ - **Half given in first 8 hours** from time of injury - **Half given over next 16 hours** - Uses **Lactated Ringer's solution** (not normal saline — avoids hyperchloremic acidosis) - Goal: urine output 0.5 mL/kg/hr (1 mL/kg/hr for electrical burns) - Titrate based on urine output, not formula alone **Clinical Pearl:** This patient is only 2 hours post-injury and has not yet received resuscitation fluids. His current BP and HR suggest he is still in the compensatory phase; without immediate fluid resuscitation, he will decompensate into irreversible shock within the next 4–6 hours. ## Timing and Sequence | Phase | Timing | Priority | |-------|--------|----------| | **Immediate (0–2 hrs)** | Airway, breathing, circulation; fluid resuscitation initiation | Parkland formula START | | **Early (2–8 hrs)** | Continue Parkland; monitor urine output; prepare for intubation if needed | Titrate fluids | | **Inhalation injury management** | Assess, intubate if stridor/respiratory distress; bronchoscopy if soot in airway | Parallel to resuscitation | | **Wound care** | After resuscitation is underway; topical agents, escharotomy if needed | Secondary priority | ## Why Not the Other Options? **Mnemonic: ABCDE of Burn Management** - **A**irway (assess for inhalation injury) - **B**reathing (supplemental O₂, intubate if needed) - **C**irculation (fluid resuscitation — THIS IS FIRST) - **D**isposition (transfer to burn center) - **E**xcision and grafting (later) While this patient has signs of inhalation injury, his airway is currently patent and he is oxygenating adequately. Intubation is indicated only if there is stridor, respiratory distress, or inability to protect airway — **not prophylactically**. Topical agents and escharotomy are important but come **after** resuscitation is established and the patient is stabilized.