Surgery and Allied Specialties: Trauma, Burns and Perioperative Care
Surgery questions favour resuscitation physiology, decision thresholds and complications. Trauma, burns, compartment syndrome, hernia, thyroid and breast disease, orthopaedic emergencies, anaesthetic crises and the red eye are the dependable areas.
Core rules
- ATLS sequence is airway, breathing, circulation, disability, exposure; permissive hypotension applies to penetrating trauma without head injury.
- Parkland formula: 4 mL x body weight in kg x percentage TBSA in the first 24 hours, half in the first 8 hours from the time of the burn.
- Compartment syndrome: pain out of proportion, pain on passive stretch; fasciotomy when compartment pressure exceeds 30 mmHg or is within 30 mmHg of diastolic pressure.
- Malignant hyperthermia: stop the trigger, hyperventilate with 100 percent oxygen, give dantrolene 2.5 mg/kg.
Worked example
A 70 kg man has 40 percent TBSA partial-thickness burns and arrives 4 hours after injury. Total fluid = 4 x 70 x 40 = 11,200 mL in 24 hours. Half, 5600 mL, is due in the first 8 hours from the burn, of which 4 hours have already elapsed, so 5600 mL must be given over the next 4 hours, and the remaining 5600 mL over the following 16 hours. Urine output of 0.5 mL/kg/h guides titration.
Traps
- Timing the Parkland clock from hospital arrival rather than from the burn.
- Choosing escharotomy when the problem is a deep compartment requiring fasciotomy.
- Using nitrous oxide in bowel obstruction or pneumothorax.