Thermal Burns

1. THE 2-MINUTE PHYSIOLOGY (Rapid Pathophysiology)

• The Inflammatory Cascade & Burn Shock: The systemic impact of a major thermal injury is directly linked to the massive inflammatory response it triggers. Heat denatures proteins, causing immediate coagulative necrosis, but the ensuing profound inflammatory cascade develops gradually over the hours immediately following the injury.
• Capillary Leak & Hypoperfusion: This inflammatory storm drastically increases capillary permeability, leading to massive intravascular fluid extravasation into the interstitial space. Without immediate and aggressive volume replacement, this progresses rapidly to "burn shock"—a distributive and hypovolemic state resulting in multiorgan failure and death.
• Mechanical Compromise: Severe thermal injuries cause eschar formation. When these burns are circumferential around an extremity or the thorax, the rigid eschar cannot expand with the developing edema, creating a mechanical tourniquet that rapidly severely restricts distal tissue perfusion or prevents adequate respiratory chest excursion.

2. THE BEDSIDE ACTION PLAN (Rapid ER Management)

• Immediate Stabilization (Stop & Warm): You must immediately stop the burning process by quickly removing all involved or wet clothing. Because burn patients rapidly lose thermoregulation, you must actively mitigate hypothermia by minimizing exposure time, using active warming measures, and quickly applying warm blankets after assessment.
• Airway & Breathing: Maintain a remarkably low threshold for emergent airway control (endotracheal intubation or cricothyroidotomy) before progressive airway edema obscures landmarks. Utilize warmed ventilator circuits. For circumferential chest burns limiting ventilation, immediate escharotomies are required.
• Fluid Resuscitation:
• Primary Survey: Initiate fluid resuscitation immediately using warmed Lactated Ringer's at fixed rates based purely on the patient's age.
• Secondary Survey: Transition to adjusted fluid rates calculated based on the precise burn size (% Total Body Surface Area [TBSA]) and the patient's weight.
• Critical Titration: You must adjust the IV fluid rates hourly based strictly on the patient’s physiologic response (e.g., urine output), beginning at hour 1.
• Minor Burns: For minor thermal burns presenting early, run cool water over the burned area for 20 minutes (if within 3 hours of injury).

3. THE DIAGNOSTIC GRID (Differential Diagnosis & Workup)

• Critical "Can't-Miss" Concomitant Pathologies:
• Carbon Monoxide (CO) Poisoning & Cyanide Toxicity: Must be suspected in any patient injured in an enclosed space fire (burning plastics release cyanide).
• Concomitant Trauma: Always investigate if the patient fell, jumped to escape the fire, or was involved in an explosion (blast injuries).
• Non-Accidental Trauma: Thermal injuries can be a primary manifestation of child abuse or elder abuse.
• Prioritized Diagnostic Workup:
• Co-Oximetry / Arterial Blood Gas: Mandatory to screen for elevated carboxyhemoglobin (CO poisoning) and profound acidosis/hyperlactatemia (suggesting cyanide toxicity).
• Burn Size & Depth Calculation: Accurately estimate the size (% TBSA) and depth (partial vs. full thickness) of the burn to guide exact fluid resuscitation needs.
• Trauma Panels: CBC, comprehensive metabolic panel, coagulation studies, and baseline CK/urinalysis to establish end-organ function and detect rhabdomyolysis.
• Imaging: Obtain a chest X-ray to evaluate for concomitant pulmonary blast injury, ARDS, or pneumonia, and targeted X-rays to rule out fractures if a fall or jump occurred.

4. THE VISUAL BOARD (ECG / POCUS / Imaging)

• The Clinical Exam (Pattern Recognition):
• Airway Exam: Explicitly look for singed facial hair, soot in the oropharynx, hoarseness, stridor, dysphagia, or facial flash burns. These are the visual and auditory hallmarks of impending airway disaster.
• The Extremities: Evaluate for circumferential burns. Palpate compartments and use a Doppler to assess distal pulses to rule out impending compartment syndrome.
• Abuse Patterns: Look for circumferential immersion burns with explicit "sparing over the flexor areas." This indicates the hand or limb was forcibly held clenched in a boiling liquid, a classic sign of elder or child abuse.

5. THE SCORING MATRIX (Risk Stratification & Guidelines)

• American Burn Association (ABA) Burn Center Transfer Criteria (2022): You must consult and transfer patients to a specialized Burn Center if they meet any of the following definitive criteria:
• Full thickness burns of any size.
• Partial thickness burns > 10% of the total body surface area.
• Any deep partial or full thickness burns involving the face, hands, feet, genitalia, perineum, or over any joints.
• Patients with suspected inhalation injury (e.g., facial flash burns, singed hair, smoke exposure).
• Patients with significant preexisting medical comorbidities or concomitant traumatic injuries.

6. THE DANGER ZONE (Pitfalls & Critical Actions)

• Pitfall (The "Wait and See" Airway): Failing to secure the airway early in a patient with facial burns or hoarseness. Burn inflammation and edema are progressive; waiting until the patient is in extremis will result in a catastrophic loss of the airway.
• Pitfall (The Hypothermia Trap): Forgetting that a burn patient has lost their primary barrier for thermoregulation. Leaving them exposed on a cold spine board or in wet clothing is a deadly error that rapidly induces coagulopathy and hypothermia.
• Pitfall (Blind Fluid Administration): Calculating the Parkland or ATLS fluid formula and leaving the rate static. Fluids must be actively and frequently adjusted hourly based on the patient's physiologic response. Conversely, initiating massive formulaic fluid resuscitation for isolated minor burns (e.g., <10% TBSA hand burn) is not indicated and causes dangerous fluid overload.
• CRITICAL ACTION: You must actively search for signs of elder or child abuse. Circumferential hand burns with spared flexor creases mandate contacting Adult or Child Protective Services and admitting the patient for safety, regardless of the % TBSA.

7. MCQ MASTERCLASS (Written Exam Tips)

• Buzzwords: "Enclosed space fire," "burning plastics," "unexplained profound lactic acidosis" $\rightarrow$ Suspect concomitant Cyanide toxicity alongside Carbon Monoxide poisoning.
• Buzzwords: "Hoarseness, dysphagia, stridor, singed facial hair" $\rightarrow$ Indicates inhalation injury. The correct answer is always early, prophylactic endotracheal intubation.
• Common Distractor: A question stem presents a patient with a 5% TBSA isolated thermal burn to the forearm and asks for the initial fluid management. Distractor options will list complex Parkland/ATLS fluid calculations. The correct answer is that fluid formulas are generally reserved for major burns (>10-15% TBSA); isolated minor burns do not require massive IV fluid protocols.
• Common Distractor: A severe burn patient arrives with an oxygen saturation of 100% on a standard pulse oximeter but is confused after a house fire. Do not be tricked into discharging or observing; standard pulse oximetry cannot distinguish oxyhemoglobin from carboxyhemoglobin. You must obtain a co-oximetry panel.

8. THE BOARDROOM SCRIPT (OSCE & Oral Board Tips)

• High-Stress Articulation: "This patient presents with a major thermal burn sustained in an enclosed space fire. I will immediately assess the airway for signs of thermal injury. Given his hoarseness and singed facial hair, I am preparing for rapid sequence intubation with a warmed ventilator circuit before progressive edema obliterates the airway."
• Mandatory Physical Exam Maneuvers: "I am fully undressing the patient to stop the burning process, but will rapidly cover him with warm blankets to prevent hypothermia. I will systematically calculate the % TBSA and burn depth. I am explicitly examining his chest and extremities for circumferential burns that would necessitate an emergent escharotomy."
• Communication Pearl (Disposition & Resuscitation): "Nurse, please establish two large-bore IVs and initiate warmed Lactated Ringer's at the fixed age-based rate, while I calculate our exact secondary fluid requirements based on his weight and burn size. We will titrate these fluids hourly to his urine output. I am also calling the regional Burn Center now to arrange for emergent transfer as his injuries involve greater than 10% TBSA and cross major joints."