Perioperative Management of Antihypertensive Medications
Most antihypertensive medications should be continued on the day of surgery with a small sip of water, with the notable exception of ACE inhibitors and ARBs, which should be discontinued 24 hours before surgery. 1
Medications to CONTINUE
Beta Blockers (MUST Continue)
- Beta blockers must be continued in all patients who have been taking them chronically to prevent potentially harmful rebound hypertension and cardiovascular complications 2, 1
- Abrupt preoperative discontinuation of beta blockers is classified as potentially harmful (Class III: Harm recommendation) 2
- This applies specifically to patients on chronic beta blocker therapy prescribed according to guideline-directed medical therapy 1
Clonidine (MUST Continue)
- Abrupt discontinuation of clonidine is potentially harmful due to severe rebound hypertension 2, 1
- Continue through the morning of surgery with a small sip of water 1
Other Antihypertensives (Generally Continue)
- Calcium channel blockers, alpha blockers, and other non-ACEI/ARB antihypertensives should be continued until surgery 2, 1
- These can be taken on the morning of surgery with a small sip of water 1
Diuretics (Context-Dependent)
- Diuretics for heart failure should be continued up to the day of surgery 1
- Diuretics for hypertension alone can be discontinued on the day of surgery and resumed when oral intake resumes 1
- Ensure electrolyte abnormalities (especially hypokalemia and hypomagnesemia) are corrected preoperatively 1
Medications to DISCONTINUE
ACE Inhibitors and ARBs (Consider Discontinuation)
- Discontinuation of ACE inhibitors or ARBs 24 hours before surgery may be considered (Class IIb recommendation) to reduce risk of intraoperative hypotension 2, 1
- The mechanism relates to increased risk of acute kidney injury with hemodynamic challenges during surgery 2
- Research evidence supports this approach: patients continuing ACEIs/ARBs have 41% higher risk of intraoperative hypotension (RR = 1.41,95% CI: 1.21-1.64) 3
- Multiple studies demonstrate more frequent and severe hypotensive episodes requiring vasopressor treatment when these medications are continued 4, 5
- Importantly, discontinuation does NOT increase risk of postoperative complications including myocardial infarction, stroke, acute kidney injury, or death 3, 6
Critical CONTRAINDICATIONS
Never Start Beta Blockers Perioperatively
- Beta blockers must NOT be initiated on the day of surgery in beta blocker-naive patients (Class III: Harm recommendation) 2, 1
- This increases risk of perioperative harm including stroke and death 1
Blood Pressure Thresholds for Surgery
Severe Hypertension
- Consider deferring elective major surgery if blood pressure is ≥180/110 mmHg (Class IIb recommendation) 2, 1
- Target blood pressure control to <130/80 mmHg before major elective procedures 1
Intraoperative Management
Treatment of Hypotension
- Be prepared for intraoperative hypotension, particularly in patients who continued ACEIs/ARBs 3
- Use intravenous vasopressors (ephedrine, phenylephrine, or vasopressin) as needed 5
- Some cases may require higher doses or multiple agents 3
Treatment of Hypertension
- Manage intraoperative hypertension with IV medications: clevidipine, esmolol, or nicardipine 1
- Assess contributing factors: volume status, pain control, oxygenation, bladder distention 1
- Perioperative hypertension is defined as BP ≥160/90 mmHg or SBP elevation ≥20% above baseline persisting >15 minutes 1
Common Pitfalls to Avoid
Rebound Hypertension
- Never abruptly stop beta blockers or clonidine - this can cause life-threatening rebound hypertension 2, 1
- Even if surgery is cancelled, continue these medications 1
Anesthetic Interactions
- Be aware of synergism between labetalol and halothane anesthesia, which has been associated with deaths during surgery 7
- Avoid nitrates in patients taking phosphodiesterase-5 inhibitors due to risk of profound hypotension 1