Preoperative Assessment and Preparation
Core concepts
Preoperative assessment is risk stratification, not a ritual checklist. Focus on the three questions every exam item circles: What is the patient's baseline physiologic reserve? What is the surgical stress (urgency, duration, blood loss, position, airway)? What modifiable factors can be optimized before induction?
Key areas: cardiovascular risk indices (revised cardiac risk index, functional capacity in METs, the role of stress testing only when it changes management), pulmonary risk (smoking cessation timing, obstructive sleep apnea screening with STOP-BANG, COPD optimization), endocrine disease (diabetes glucose targets, thyroid, adrenal insufficiency and steroid coverage), anticoagulation and antiplatelet management with neuraxial timing, NPO intervals for clear liquids, breast milk, and solids, and premedication decisions.
Traps
- Confusing which patients benefit from stress testing: stable patients undergoing low-risk surgery generally do not.
- Applying adult NPO rules to infants or forgetting that clear liquids have a shorter fasting interval than solids.
- Assuming all anticoagulants have the same neuraxial hold time; direct oral anticoagulants differ by agent and renal function.
- Missing that a patient's functional capacity (can they climb stairs?) may matter more than a resting ECG.
Rule of thumb
If a test result would not change your anesthetic plan or delay surgery for a fixable problem, it probably is not indicated. Optimize what is modifiable (glucose, electrolytes, anemia, infection, smoking) and document informed consent and airway risk.
Worked example
A 68-year-old with well-controlled hypertension and no symptoms, scheduled for a low-risk outpatient procedure, has an ECG showing an old minor change. Functional capacity is excellent. The correct approach is to proceed; further cardiac testing is not indicated because it would not alter management.