What are the guidelines for adjusting non-insulin medications, such as anticoagulants (e.g. warfarin), antiplatelet agents (e.g. aspirin), and medications for hypertension (e.g. beta-blockers, ACE inhibitors), before surgery?

Preoperative Management of Non-Insulin Medications

For most non-insulin medications, continue chronic therapy perioperatively with specific exceptions: hold metformin and oral hypoglycemics on the day of surgery, discontinue SGLT2 inhibitors 3-4 days before surgery, stop ARBs 24 hours preoperatively, and manage anticoagulants based on bleeding versus thrombotic risk.

Antihypertensive Medications

Beta-Blockers

• Continue beta-blockers in all patients currently taking them chronically, particularly when prescribed for guideline-directed medical therapy (e.g., post-MI) 1.
• Never initiate beta-blockers on the day of surgery in beta-blocker-naïve patients—this increases harm 1.
• If starting beta-blockers perioperatively is deemed necessary (patients with ≥3 Revised Cardiac Risk Index factors or intermediate/high-risk preoperative tests), begin >1 day before surgery to assess safety and tolerability 1.

ACE Inhibitors and ARBs

• Discontinue ARBs 24 hours before major surgery to reduce intraoperative hypotension risk 2.
• Recent cohort evidence demonstrates that stopping ARBs 24 hours preoperatively reduces both composite adverse outcomes and intraoperative hypotension compared to continuation 2.
• Continuation of ACE inhibitors or ARBs is reasonable perioperatively, though this remains controversial 1.
• Restart ARBs/ACE inhibitors as soon as clinically feasible postoperatively once hemodynamic stability and adequate volume status are confirmed 1, 2.
• Exception: For patients with left ventricular systolic dysfunction, consider continuing ARBs under close monitoring 2.

Calcium Channel Blockers

• Continue calcium channel blockers throughout the perioperative period 2.
• Unlike ARBs, CCBs do not typically cause significant intraoperative hypotension warranting discontinuation 2.
• CCBs reduce perioperative ischemia and supraventricular tachycardia 2.

Diuretics

• Discontinue diuretics on the day of surgery and resume postoperatively 3.

Alpha-2 Agonists

• Do not use alpha-2 agonists for prevention of cardiac events 1.

Statin Therapy

• Continue statins in all patients currently taking them throughout the perioperative period 1, 4.
• Statins reduce perioperative mortality (59% reduction in vascular surgery, 44% reduction overall) and major adverse cardiovascular events through pleiotropic effects including plaque stabilization and decreased vascular inflammation 4.
• Discontinuation may cause rebound effects that increase cardiovascular risk 4.
• If oral administration is temporarily impossible, resume as soon as the patient can take oral medications 4.
• Prefer long half-life statins (atorvastatin, rosuvastatin) to bridge periods when oral administration may not be possible 4.

Diabetes Medications

Oral Hypoglycemic Agents

• Hold metformin on the day of surgery 1.
• Discontinue SGLT2 inhibitors 3-4 days before surgery 1.
• Withhold all other oral glucose-lowering agents the morning of surgery 1.
• Recent evidence suggests continuing oral hypoglycemics preoperatively results in lower perioperative blood glucose (138 mg/dL vs 156 mg/dL) without increased hypoglycemia risk 5, though current guidelines still recommend holding them 1.

GLP-1 Receptor Agonists

• Little data exists on safe use and influence on glycemia and delayed gastric emptying perioperatively 1.
• Exercise caution given potential for delayed gastric emptying 1.

Insulin Management

• Give 50% of NPH dose or 75-80% of long-acting analog insulin the morning of surgery 1.
• Reducing basal insulin by 25% the evening before surgery achieves perioperative glucose goals with lower hypoglycemia risk 1.
• Target perioperative blood glucose: 100-180 mg/dL (5.6-10.0 mmol/L) within 4 hours of surgery 1.
• Monitor blood glucose every 2-4 hours while NPO and dose with short/rapid-acting insulin as needed 1.
• Do not use CGM alone for glucose monitoring during surgery 1.

Anticoagulant and Antiplatelet Therapy

Warfarin

• Discontinue warfarin before surgery with timing based on bleeding versus thrombotic risk 6.
• The anticoagulant effect persists beyond 24 hours 6.
• Obtain PT/INR just prior to any dental or surgical procedure 6.
• For minimal invasive procedures, adjust warfarin to maintain PT/INR at the low end of therapeutic range 6.
• When interrupting warfarin, strongly consider benefits versus risks even for short periods 6.

Antiplatelet Agents

• Continue dual antiplatelet therapy (DAPT) in patients undergoing urgent surgery within 4-6 weeks after stent placement, unless bleeding risk outweighs stent thrombosis prevention 1.
• If P2Y12 inhibitors must be discontinued, continue aspirin and restart P2Y12 inhibitor as soon as possible postoperatively 1.
• For patients without prior stenting undergoing non-cardiac/non-carotid surgery, continuing aspirin may be reasonable only when cardiac event risk outweighs bleeding risk 1.
• Aspirin is not beneficial in elective non-cardiac non-carotid surgery without previous coronary stenting 1.
• Management decisions should involve consensus between treating clinicians and patient 1.

Heparin Bridging

• For chronic atrial fibrillation patients, 72% of anesthesiologists favor heparin bridging preoperatively 7.
• When converting from heparin to warfarin postoperatively, overlap for 4-5 days until therapeutic PT/INR is achieved 6.

Glucocorticoid Considerations

• For patients on daily intermediate-acting glucocorticoids (prednisone), administer NPH insulin concomitantly with steroids to cover disproportionate daytime hyperglycemia 1.
• Glucocorticoid-induced hyperglycemia occurs in 56-86% of hospitalized patients and increases mortality and morbidity if untreated 1.
• Adjust insulin based on anticipated glucocorticoid dosing changes and point-of-care glucose monitoring 1.

Key Perioperative Principles

• Obtain PT/INR determination just prior to any dental or surgical procedure in anticoagulated patients 6.
• For patients with intraoperative hypertension, manage with intravenous medications until oral medications can be resumed 1.
• Target blood pressure <130/80 mm Hg before elective major procedures when possible 1.
• Consider deferring elective major surgery in patients with poorly controlled hypertension 2.