Risk Factors for Intraoperative Hypotension Under General Anesthesia: Clinical Predictors and Preventive Strategies

Abstract

Background. Intraoperative hypotension (IOH) is among the most frequent hemodynamic disturbances during general anesthesia and is consistently associated, in a severity- and duration-dependent manner, with acute kidney injury, myocardial injury, major adverse cardiovascular events and mortality. Yet recent large randomized trials testing higher or individualized blood pressure targets have largely been neutral, sharpening the question of which patients are at risk, why, and which preventive measures are worth implementing.
Objective. To synthesize current evidence on patient-, medication-, anesthesia- and surgery-related risk factors for IOH; to appraise clinical and machine-learning prediction tools; to critically evaluate preventive and treatment strategies in light of trials published up to 2025; and to propose an implementable, risk-stratified framework for practice and health-system quality improvement.
Methods. Narrative review informed by the SANRA quality criteria. MEDLINE/PubMed, Embase, Web of Science and the Cochrane Library were searched for adult studies of IOH under general anesthesia, with priority given to large cohort studies, systematic reviews, consensus statements and randomized controlled trials.
Results. Consistent independent predictors of IOH include advanced age, ASA physical status III–IV, low pre-induction blood pressure, chronic hypertension, emergency surgery, renin–angiotensin system inhibitor continuation, propofol induction and higher opioid induction doses, and combined neuraxial–general anesthesia. Thresholds below a mean arterial pressure of 65 mmHg, and particularly below 55 mmHg, are associated with organ injury. Predictive algorithms can anticipate hypotension minutes in advance and reduce its depth and duration, but neither predictive monitoring nor elevated or individualized targets have yet been shown to improve hard clinical outcomes in large trials (POISE-3, Stop-or-Not, IMPROVE-multi, PRETREAT).
Conclusions. IOH is largely predictable and partly preventable. Current evidence supports avoiding sustained MAP below 65 mmHg, anticipating post-induction hypotension in high-risk patients, judicious induction dosing and continuous monitoring when risk is high, while reserving routinely elevated targets for research. The proposed PREVENT framework operationalizes these principles for clinical teams and quality systems, including those undergoing transformation under Saudi Vision 2030.