Postoperative hypotension in patients recovering from noncardiac surgery: a prospective, blinded observational study.

Abstract

Postoperative complications can cause alterations in vital signs, including blood pressure. The duration and severity of postoperative hypotension, as well as its clinical relevance, remain poorly understood. In this single-centre prospective observational study, we quantified the incidence, duration, and severity of postoperative hypotension, defined as a mean arterial pressure (MAP) <65 mm Hg within the first 3 postoperative days, during recovery from noncardiac surgery. Postoperative blood pressure was monitored using blinded automated oscillometric blood pressure monitoring at 1-h intervals. On an exploratory basis, we also recorded postoperative complications within the first 7 postoperative days. Data are presented as median (25th, 75th percentile). From February 2024 to July 2025, automated blood pressure monitoring was recorded in 1002 participants (age 58 [42-72] yrs; 50% female) for 48 (24, 64) h. Postoperative hypotension was recorded in 378/1002 (37.7%) participants, with a median cumulative duration of 180 (71, 420) min, corresponding to 7.1% (3.3%, 16.3%) of their monitoring time. The median area under a MAP of 65 mm Hg was 836 (300, 2037) mm Hg x min. The median time-weighted average MAP <65 mm Hg was 0.32 (0.12, 0.73) mm Hg. The incidence of postoperative hypotension progressively decreased from 30% of participants on postoperative day 1 to 17% of participants on postoperative day 3. Participants with postoperative hypotension had higher rates of acute kidney injury and unplanned admissions to the intensive care unit. During recovery from noncardiac surgery, postoperative hypotension is common, but rarely severe or prolonged. The incidence of postoperative hypotension progressively decreases from postoperative day 1 to day 3.