Continuing versus Withholding renin angiotensin aldosterone system antagonists before non-cardiac surgery: A protocol...

Perioperative use of ACE inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) has been linked to early postinduction hypotension requiring vasopressor use under general anesthesia, potentially leading to complications like acute renal injury, myocardial injury, or stroke. However, the relationship between perioperative ACEI/ARB use and major morbidity remains uncertain.

This meta-analysis assessed the differences between the continuation or discontinuation of ACE inhibitor (ACE-I) or angiotensin II receptor blocker (ARB) therapy during the perioperative period and hemodynamical instability, mortality, and major morbidity outcomes.

The protocol was registered in the PROSPERO database (ID: CRD42024519162). Literature searches of electronic databases and manual searches on the Medline, Embase, Scopus, and Web of Science databases up to August 30, 2024, will be performed. Case-control studies, cohort studies, non-randomized controlled trials, and randomized controlled trials (RCTs) involving adult patients aged over 18 years, who were chronically using ACEIs or ARBs due to chronic hypertension, undergoing non-cardiac surgery, where ACEIs or ARB therapy was either withheld or continued less than 10 hours before surgery will be included. The primary outcome will be the incidence of intraoperative hypotension. Secondary outcomes will be the intraoperative use of vasoactive agent (incidence, dose of ephedrine (mg) and dose of phenylephrine (ng)), the incidence of severe hypotension, hospital length of stay, intraoperative and postoperative hypertension, the incidence of acute kidney injury, 30-day postoperative all-cause mortality and incidence of major cardio-cerebral events.

The results of this systematic review and meta-analysis should provide evidence for withholding or continuing perioperative ACE-I or ARB in noncardiac surgery.