Perioperative Management of Hypertension and Diabetes

Introduction to Perioperative Care

The British Hypertension Society and Association of Anaesthetists state that postponing surgery for assessment of cardiovascular risk may not affect the lifelong risk of mortality and morbidity, with each postponed month adding a 1% relative increase in cardiovascular risk due to patient aging 1, 2
The American College of Cardiology/American Heart Association (ACC/AHA) recommends blood pressure control to <130/80 mmHg before elective procedures, but does not mandate postponement for blood pressure 160/95 mmHg 3

The American Diabetes Association recommends a perioperative blood glucose target of 100-180 mg/dL (5.6-10.0 mmol/L) within 4 hours of surgery 4, 5
The A1C target for elective surgeries should be <8% whenever possible, although the current patient's A1C value is not available 4, 5, 6
Metformin should be held on the day of surgery, and SGLT2 inhibitors should be discontinued 3-4 days before surgery to prevent euglycemic diabetic ketoacidosis 4, 5
Other oral glucose-lowering agents should be held the morning of surgery, and 75-80% of the long-acting insulin dose or half of the NPH dose should be given based on the patient's regimen 4, 5
Blood glucose should be monitored every 2-4 hours while the patient is NPO, and short- or rapid-acting insulin should be dosed as needed 4, 5
Basal-bolus insulin coverage should be used postoperatively rather than correction-only insulin, as this improves outcomes and reduces perioperative complications 4, 5

The ACC/AHA recommends blood pressure control to <130/80 mmHg before major elective procedures when reasonable, and patients with controlled hypertension respond similarly to normotensive patients during anesthesia 3
ACE inhibitors/ARBs should be held 24 hours before surgery to reduce intraoperative hypotension and composite outcomes, although this remains somewhat controversial 3
Beta blockers and clonidine must be continued to avoid rebound hypertension, while other antihypertensives can generally be continued 3

Antihypertensive regimen should be adjusted to target blood pressure <130/80 mmHg, and diabetes medications should be optimized for the perioperative period 3, 4, 5
A1C should be obtained if not done in the past 3 months, and metformin and SGLT2 inhibitors should be held on the day of surgery or stopped 3-4 days prior, respectively 4, 5, 6
Blood glucose should be monitored every 2-4 hours while the patient is NPO, and short- or rapid-acting insulin should be dosed as needed to maintain glucose 100-180 mg/dL 4, 5
Basal-bolus insulin regimen should be implemented postoperatively rather than sliding scale alone, and home medications should be resumed when the patient is tolerating oral intake 4, 5

Correction-only (sliding scale) insulin should not be used alone postoperatively, as this approach increases complications compared to basal-bolus coverage 4, 5
Beta blockers and clonidine should not be abruptly stopped, as this causes rebound hypertension 3
SGLT2 inhibitors should not be forgotten to be held 3-4 days before surgery, as failure to do so risks euglycemic DKA 4, 5
Perioperative glucose should not be targeted to <100 mg/dL, as stricter targets increase hypoglycemia without improving outcomes 4, 5
Surgery should not be automatically canceled for blood pressure 160/95 mmHg, as this level does not mandate postponement and delay may not improve long-term outcomes 1, 2