Medical Comorbidity Management and Pharmacology
What this domain tests
Perioperative management of diabetes, hypertension, sleep apnea, and anticoagulation, plus the pharmacology that changes once anatomy is rearranged.
Diabetes
- Stop sulfonylureas and mealtime insulin before surgery; reduce basal insulin and use a sliding scale.
- Hold SGLT2 inhibitors 3–4 days preoperatively to avoid euglycemic ketoacidosis.
- Metformin may usually continue.
- An A1C above roughly 8% is a delay-and-optimize trigger at most programs.
Other comorbidities
- Continue CPAP through the perioperative period; undiagnosed OSA is a screening target (STOP-BANG).
- Hold ACE inhibitors and ARBs on the morning of surgery per ERAS protocols.
- Anticoagulation follows procedure-specific interruption and bridging rules.
Absorption changes
- Avoid NSAIDs after RYGB because of marginal ulcer risk.
- Extended-release and enteric-coated drugs may absorb unpredictably; use immediate-release alternatives and monitor levels for levothyroxine, warfarin, phenytoin, and levodopa.
Worked example
A 58-year-old on insulin glargine 40 units and glyburide is scheduled for bypass. Reasoning: stop glyburide 24–48 hours before surgery because fasting plus a sulfonylurea causes hypoglycemia, reduce glargine to roughly 20 units or hold per protocol, and monitor glucose in recovery. Continuing both unchanged is the classic error that produces preoperative or postinduction hypoglycemia.
Traps
- Continuing glyburide on the day of surgery.
- Missing the SGLT2 inhibitor hold and mistaking normal glucose for safety.
- Assuming every medication absorbs the same after bypass.
- Forgetting that CPAP must continue postoperatively and through the night after discharge.