Anaesthesia & Peri-operative Medicine
Anaesthesia and peri-operative medicine tests preoperative risk stratification, medication management and recognition of rare anaesthetic crises.
Core rules
- Revised Cardiac Risk Index (RCRI): ischaemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, creatinine >177 µmol/L, high-risk surgery. Two or more predictors indicate elevated major cardiac event risk.
- Functional capacity ≥4 METs generally permits major surgery without further cardiac testing.
- Continue beta-blockers and statins; do not start beta-blockers on the day of surgery. Manage anticoagulants according to procedure bleed risk and thrombotic risk.
- Malignant hyperthermia: volatile agents and succinylcholine trigger it; stop triggers, hyperventilate, cool, give dantrolene 2.5 mg/kg IV.
- Local anaesthetic systemic toxicity: stop injection, secure airway, give 20% lipid emulsion 1.5 mL/kg bolus then infusion.
Worked example
A man for elective open colectomy has prior myocardial infarction, insulin-treated diabetes and creatinine 200 µmol/L. RCRI = 3 (ischaemic heart disease, insulin diabetes, creatinine >177), indicating elevated risk. Consider cardiology review and avoid dehydration, but routine preoperative revascularisation is not indicated.
Traps
- RCRI is not validated for emergency surgery.
- METs are often overestimated; ask specifically about stair climbing.
- Bridging anticoagulation increases bleeding without clear benefit in most patients.
- Neuraxial haematoma after anticoagulation is time-critical.