Should lisinopril and hydrochlorothiazide be held on the day of surgery?

Should Lisinopril and HCTZ Be Held Before Surgery?

For lisinopril (ACE inhibitor): Consider holding it 24 hours before major surgery in patients with controlled hypertension to reduce intraoperative hypotension, but continue it in patients with heart failure with reduced ejection fraction (HFrEF). For hydrochlorothiazide (HCTZ): Hold it on the day of surgery and resume when oral intake is possible 1, 2.

ACE Inhibitor (Lisinopril) Management

The Evidence Landscape

The most recent 2025 AHA/ACC hypertension guideline provides nuanced recommendations that supersede older blanket approaches 1. The key distinction is why the patient is taking the ACE inhibitor:

For patients taking lisinopril for hypertension:

• Discontinuation 24 hours preoperatively may be considered (Class 2b, Level B-R evidence) 1
• This reduces intraoperative hypotension risk without increasing major adverse cardiovascular events
• The 2024 perioperative guideline specifically states omission 24 hours before surgery "may be beneficial to limit intraoperative hypotension" in select patients with controlled BP undergoing elevated-risk surgery 2

For patients taking lisinopril for heart failure:

• Perioperative continuation is reasonable (Class 2a, Level C-EO evidence) 1, 2
• The 2009 European guidelines recommend continuation in stable patients with LV systolic dysfunction (Class I, Level C) 3
• These patients depend on RAAS inhibition for cardiac protection

The Hypotension Trade-off

Multiple guidelines acknowledge that continuing ACE inhibitors increases intraoperative hypotension risk 4, 3, 5. The 2009 ACC/AHA guideline notes "intraoperative hypotension was associated with a greater incidence of perioperative cardiac and renal complications" and suggests "withholding ACE inhibitors and angiotensin receptor antagonists the morning of surgery" 4. However, recent evidence from the SPACE trial (2024) found no increase in myocardial injury when ACE inhibitors were continued, and patients who stopped them experienced more postoperative hypertension 6.

The practical algorithm:

1. If lisinopril is for hypertension alone AND BP is controlled → Hold 24 hours before surgery
2. If lisinopril is for heart failure (HFrEF) → Continue with close monitoring
3. If severe uncontrolled hypertension (SBP ≥180 or DBP ≥110) → Consider deferring elective surgery 1

Hydrochlorothiazide (HCTZ) Management

Hold HCTZ on the day of surgery - this recommendation is more straightforward 3.

The 2009 European guideline states: "It is recommended that hypertensive patients discontinue low-dose diuretics on the day of surgery and resume orally when possible" (Class I, Level C) 3. The rationale includes:

• Risk of hypovolemia and hypotension during anesthesia induction
• Electrolyte disturbances (hypokalemia, hypomagnesemia) that increase arrhythmia risk
• Additive hypotensive effects with anesthetic agents

Electrolyte Considerations

Before holding HCTZ, verify potassium and magnesium levels 3. Hypokalaemia occurs in up to 34% of surgical patients and is "independently associated with perioperative mortality" in cardiac disease patients 3. Correct any electrolyte abnormalities before proceeding with surgery.

Resume HCTZ postoperatively when:

• Oral intake is established
• Volume status is stable
• Electrolytes are within normal range

Common Pitfalls to Avoid

1. Don't abruptly stop both medications simultaneously - The ACE inhibitor can be held 24 hours before, but don't create a medication-free period that destabilizes BP control

2. Don't confuse heart failure patients with hypertension-only patients - Heart failure patients need their ACE inhibitor continued; stopping it risks decompensation

3. Don't forget to check electrolytes - HCTZ-induced hypokalemia must be corrected preoperatively to prevent perioperative arrhythmias

4. Don't restart ACE inhibitors before euvolemia - The 2009 ACC/AHA guideline specifically warns to "restart ACE inhibitors in the postoperative period only after the patient is euvolemic, to decrease the risk of perioperative renal dysfunction" 4

5. Don't hold medications without a plan for intraoperative BP management - Have IV antihypertensives available if needed

The Bottom Line Algorithm

Day Before Surgery:

• Hold HCTZ
• Hold lisinopril (if for hypertension only)
• Continue lisinopril (if for heart failure)
• Verify electrolytes are corrected

Day of Surgery:

• Confirm medications held as planned
• Monitor for rebound hypertension
• Have IV antihypertensives available

Postoperatively:

• Resume HCTZ when oral intake established and patient euvolemic
• Resume lisinopril when hemodynamically stable and euvolemic
• Monitor renal function and electrolytes

This approach balances the risk of intraoperative hypotension against the need for cardiovascular protection, with the patient's underlying indication for therapy being the primary decision driver.