Incidence and risk factors for perioperative hypotension during noncardiac surgery: A retrospective cohort study

Perioperative hypotension (POH) is frequent in noncardiac surgery and is linked to acute kidney injury (AKI), myocardial injury after noncardiac surgery (MINS), and increased postoperative resource use. Previous studies have applied inconsistent POH definitions and risk models. This study aimed to determine the incidence of POH and identify independent risk factors, while assessing the robustness of findings across alternative thresholds. In this single-center retrospective cohort, 3000 adults (≥18 years) undergoing noncardiac surgery between April 2023 and December 2024 were analyzed using data from electronic medical and anesthesia information systems. POH was defined as intraoperative mean arterial pressure (MAP) <65 mm Hg lasting ≥5 minutes. Multivariable logistic regression identified independent predictors among prespecified covariates: American Society of Anesthesiologists (ASA) physical status, baseline MAP, surgical risk, emergency status, continuation of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) on the day of surgery, operative duration, intraoperative vasoactive use, and anesthesia modality. Sensitivity analyses tested alternative MAP thresholds (<60, <65, and <70 mm Hg). POH occurred in 775 patients (25.8%). Incidence varied by anesthesia technique-76.6% for general, 75.4% for neuraxial, and 68.7% for peripheral nerve block-and by surgical risk: 70.3% (low), 75.0% (intermediate), and 79.4% (high). Independent predictors included ASA III-IV (odds ratio [OR] 1.71, 95% confidence interval 1.44-2.02), lower baseline MAP per 10-mm Hg decrease (OR 1.19, 1.10-1.28), high- (OR 1.65, 1.30-2.11) and intermediate-risk surgery (OR 1.30, 1.08-1.56), emergency surgery (OR 1.65, 1.30-2.08), continuation of ACEI/ARB (OR 1.33, 1.10-1.60), longer operative duration (per hour: OR 1.11, 1.04-1.19), and intraoperative vasoactive use (OR 1.26, 1.07-1.49). Neuraxial anesthesia versus general anesthesia was protective (OR 0.71, 0.58-0.87). POH was associated with higher incidences of AKI (30.2% vs 2.2%), MINS (27.6% vs 1.9%), and intensive care unit admission (52.9% vs 3.0%) (all P < .001). Sensitivity analyses across MAP <60/65/70 mm Hg confirmed consistent predictors. POH is common during noncardiac surgery and strongly associated with postoperative AKI, MINS, and intensive care unit admission. Major risk factors include higher ASA class, lower baseline MAP, higher surgical risk, emergency surgery, perioperative ACEI/ARB continuation, longer duration, and vasoactive use, while neuraxial anesthesia may reduce risk. These results support individualized hemodynamic optimization to mitigate POH and its adverse outcomes.