Burn Management and Burn Reconstruction
What this domain tests
Resuscitation arithmetic, depth assessment, airway decisions, escharotomy timing, wound care and late reconstruction. Expect numerical stems and stems about timing.
Resuscitation and assessment
- Rule of Nines (adult): head 9%, each arm 9%, each leg 18%, anterior trunk 18%, posterior trunk 18%, perineum 1%. Superficial (first-degree) burns are excluded from the calculation. Children require the Lund–Browder chart because the head is proportionally larger.
- Parkland formula: 4 mL/kg/%TBSA lactated Ringer's in the first 24 hours, half in the first 8 hours timed from the moment of injury, not from arrival. Children also need maintenance fluid.
- Endpoints: urine output 0.5–1 mL/kg/h in adults and 1–2 mL/kg/h in children, plus haemodynamic and mental status. Avoid "fluid creep" from over-resuscitation.
- Jackson's zones: coagulation, stasis (salvageable if perfusion restored), hyperaemia.
Airway and escharotomy
Soot in the oropharynx, hoarseness, stridor, singed nares or a closed-space fire indicate inhalation injury - intubate early, before oedema. Carbon monoxide half-life is about 4 hours on room air and 30–60 minutes on 100% oxygen. Escharotomy is indicated for circumferential full-thickness burns with compromised distal perfusion or a rising compartment pressure, and for chest wall restriction; it is not a substitute for fasciotomy when muscle compartments are involved.
Wound care and reconstruction
- Early excision and grafting within 48–72 hours reduces mortality and blood loss.
- Silver sulfadiazine: avoid on the face, in pregnancy and in G6PD deficiency. Mafenide acetate penetrates eschar but inhibits carbonic anhydrase and causes metabolic acidosis. Silver nitrate risks hypochloraemia and staining.
- Prophylactic systemic antibiotics are not routine; they are perioperative only. Wound sepsis is suggested by counts above 10^5 organisms per gram.
- Nutrition: 1.5–2 g/kg/day protein with calculated calorie targets.
- After healing: pressure garments at 24–25 mmHg worn about 23 hours/day for 12–18 months; contracture release with Z-plasty, full-thickness grafts or dermal templates; watch for heterotopic ossification and Marjolin change.
Worked example
A 70 kg man with 30% TBSA full-thickness burns arrives 3 hours after injury. Parkland: 4 × 70 × 30 = 8400 mL over 24 hours. First 8 hours from injury = 4200 mL, so 525 mL/h; because 3 hours are already lost, deliver that 4200 mL over the remaining 5 hours, i.e. 840 mL/h. Reasoning: the clock starts at injury, and re-setting it at arrival is the classic cause of under-resuscitation.
Traps
- Counting superficial burns in TBSA.
- Using the adult Rule of Nines in an infant.
- Restarting the 8-hour clock on arrival.
- Delaying escharotomy while waiting for imaging.
- Using silver sulfadiazine on the face.