Does Lisinopril Cause Hypotension with Anesthesia?
Yes, lisinopril significantly increases the risk of perioperative hypotension during anesthesia, and current guidelines recommend withholding it on the day of surgery to reduce severe hemodynamic fluctuations.
Mechanism of Perioperative Hypotension
Lisinopril blocks angiotensin II formation, which is the body's compensatory mechanism for maintaining blood pressure during anesthesia 1. When anesthetic agents produce vasodilation and reduce sympathetic tone, patients on ACE inhibitors cannot mount an adequate compensatory response through the renin-angiotensin system 2, 1. This creates a "double hit" scenario where both the anesthetic and the ACE inhibitor work synergistically to lower blood pressure 3.
The FDA drug label explicitly warns that "in patients undergoing major surgery or during anesthesia with agents that produce hypotension, lisinopril may block angiotensin II formation secondary to compensatory renin release" 1. This hypotension can be severe enough to cause oliguria, progressive azotemia, acute renal failure, or death 1.
Evidence-Based Perioperative Management
Preoperative Discontinuation Strategy
The 2017 ACC/AHA guidelines and 2009 European Society of Cardiology guidelines both recommend transient discontinuation of ACE inhibitors before non-cardiac surgery 2. The American Heart Association specifically states that ACE inhibitors should be omitted on the day of surgery to reduce significant perioperative hemodynamic fluctuations 4.
The European guidelines note that "perioperative use of ACE inhibitors carries a risk of severe hypotension under anaesthesia, in particular following induction and concomitant β-blocker use" and that "hypotension is less frequent when ACE inhibitors are discontinued the day before surgery" 2.
Timing of Discontinuation
Research demonstrates that stopping lisinopril at least 10 hours before surgery reduces the risk of postinduction hypotension 5. In a study of 267 patients, those who took their last ACE inhibitor dose less than 10 hours before surgery had a 60% incidence of moderate hypotension compared to 46% in those who stopped it 10 or more hours prior (adjusted odds ratio 1.74, p=0.04) 5.
However, some cases show that even 24-hour discontinuation may be insufficient for preventing refractory hypotension, particularly with longer-acting agents 6, 7.
Clinical Presentation and Severity
Induction Period Risk
The highest risk period is during anesthetic induction and the first 30 minutes thereafter 5. The 2003 JNC-7 guidelines note that patients receiving antihypertensive drugs face particular risk of hypotension when general anesthesia is administered, as blood pressure should be monitored closely due to potential wide fluctuations 2.
Refractory Hypotension
When ACE inhibitor-associated hypotension occurs, it can be refractory to traditional vasopressors like ephedrine and phenylephrine 3. This occurs because ACE inhibitors deplete angiotensin II, which is necessary for these agents to work effectively 3. In such cases, vasopressin or methylene blue may be required as rescue therapy 3.
Special Populations Requiring Continued Therapy
Heart Failure Patients
The major exception to discontinuation is patients with left ventricular systolic dysfunction in stable clinical condition 2, 4. The European guidelines state "it is recommended that ACE inhibitors be continued during non-cardiac surgery in stable patients with LV systolic dysfunction" (Class I recommendation) 2. The American Heart Association similarly recommends continuing ACE inhibitors in cardiac-stable patients with LV systolic dysfunction scheduled for high-risk surgery 4.
For these patients, the benefits of maintaining cardiac function outweigh the hypotension risk, but they require close hemodynamic monitoring 2.
Practical Management Algorithm
For Hypertension Without Heart Failure:
- Stop lisinopril 24 hours before surgery 2, 4
- Ensure adequate hydration status preoperatively 1
- Have vasopressin available for potential refractory hypotension 3
- Resume therapy postoperatively once oral intake is established and volume status is stable 2, 4
For Heart Failure With Preserved Function:
- Continue lisinopril through the perioperative period 2, 4
- Implement intensive hemodynamic monitoring 2
- Prepare for aggressive fluid and vasopressor management 1
- Avoid hypovolemia and correct electrolyte abnormalities preoperatively 2
Critical Pitfalls to Avoid
Never abruptly discontinue ACE inhibitors in heart failure patients, as this can precipitate acute decompensation 2. The risk-benefit calculation differs fundamentally between hypertension management (where discontinuation is preferred) versus heart failure management (where continuation is essential) 2, 4.
Do not assume 24-hour discontinuation is always sufficient 6, 7. Individual patient factors including renal function, volume status, and concurrent medications (especially diuretics and beta-blockers) can prolong the hypotensive risk 2, 1.
Recognize that standard vasopressors may be inadequate 3. If hypotension persists despite phenylephrine and fluid administration, consider vasopressin as the definitive treatment for ACE inhibitor-induced refractory hypotension 3.