Preoperative Assessment and Perioperative Risk Management
What the exam tests
Preoperative assessment questions test risk stratification, not blanket testing. You must decide what changes management: airway, functional capacity, comorbidities, anticoagulation, fasting, and consent.
Core rules
- ASA physical status is a descriptor of disease, not a calculated surgical risk.
- RCRI predicts major adverse cardiac events: high-risk surgery, ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, creatinine >2.0 mg/dL. It does not include age.
- Functional capacity <4 METs warrants further evaluation when it changes decisions.
- Routine tests are low-yield in healthy patients; ECG, chest X-ray, and coagulation are targeted.
- Fasting: clear fluids 2 h, breast milk 4 h, infant formula 6 h, light meal 6 h. Continue most chronic drugs; hold SGLT2 inhibitors 3-4 days.
- STOP-BANG screens OSA; a high score triggers perioperative planning, not automatic cancellation.
Worked example
A 68-year-old for open colectomy has prior MI, insulin-treated diabetes, and creatinine 2.3 mg/dL. RCRI factors: high-risk surgery, ischemic heart disease, insulin-treated diabetes, renal impairment = 4. Estimated 30-day MACE risk is elevated. Reasoning: count only defined variables; age and hypertension are not RCRI items. The plan should include cardiology input if symptoms changed, optimized glucose, and postoperative monitoring.
Traps
Calling ASA IV "high risk" without defining risk; ordering tests because they are available; stopping antiplatelets without a plan; misstating fasting times; treating an OSA score as a diagnosis.