Surgery and Allied Disciplines: assessment, fluids and the acute abdomen
Surgical items are written around decisions made under time pressure: resuscitate before operate, recognise the patient who cannot wait, and know the numbers that drive fluid and burn management. Pre-operative assessment, wound healing, hernia anatomy and the physiology of the acute abdomen recur.
Core rules
- Primary survey order in trauma is catastrophic haemorrhage control, airway, breathing, circulation, disability, exposure; a tension pneumothorax is decompressed clinically, never after a chest radiograph.
- Shock is inadequate tissue perfusion; classify by cause and treat the cause, using crystalloid cautiously in bleeding, where blood products and haemorrhage control are the priority.
- Wound healing: inflammatory, proliferative and remodelling phases; wounds gain about 20% of final tensile strength by three weeks and never exceed roughly 80% of uninjured skin.
- Hernia: indirect inguinal passes lateral to the inferior epigastric vessels through the deep ring; direct passes medial to them through Hesselbach's triangle.
Worked example
A 70 kg adult with 30% total body surface area partial and full thickness burns, injured 2 hours ago. Parkland formula gives 4 mL x body weight in kg x percentage TBSA = 4 x 70 x 30 = 8400 mL of crystalloid over 24 hours from the time of injury, half in the first 8 hours and half in the next 16. Since 2 hours have already passed, the remaining first-phase volume is given over the next 6 hours. Superficial epidermal-only erythema is excluded from the TBSA calculation.
Traps that cost marks
- Timing resuscitation from the moment of injury, not from arrival in the emergency department.
- Including simple erythema in burn surface area, which overestimates fluid needs.
- Choosing imaging before decompression in a crashing patient with a tension pneumothorax.
- Assuming all postoperative fever is infection; atelectasis and drug reactions are earlier causes.