Abstract
OBJECTIVE: Evaluate the feasibility of a trial of perioperative hypotension and serious complications. DESIGN: A patient and assessor-blinded randomised feasibility trial. SETTING: We included patients in a tertiary university hospital. PARTICIPANTS: We enrolled 80 adults scheduled for major non-cardiac surgery. INTERVENTIONS: In patients randomised to tight blood pressure control, intraoperative mean arterial pressure (MAP) was targeted to ≥85 mm Hg maintained with norepinephrine infusion, and restarting chronic antihypertensive medications was delayed until the third postoperative day. In the reference group, intraoperative blood pressure was managed per routine and antihypertensive medications were restarted immediately after surgery. PRIMARY AND SECONDARY OUTCOME MEASURES: Our first co-primary outcome was the fraction of time when intraoperative MAP was >85 mm Hg, intraoperative area (time integral) of MAP >85 mm Hg and MAP <65 mm Hg. The second co-primary outcome was time until antihypertensive medications were restarted after surgery. Secondary outcomes were time-weighted average intraoperative MAP, cumulative minimum MAP for 10 min, average postoperative systolic blood pressure (SBP) and mean of the lowest three postoperative SBPs. RESULTS: Forty patients in each group were analysed. The median for intraoperative area of MAP >85 mm Hg was 1303 (772-2419) mm Hg*min in routine blood pressure (BP) cases and 2425 (1926-3545) mm Hg*min in tight BP control. The area for intraoperative MAP <65 mm Hg was 7 (0-40) mm Hg*min with routine BP management, and 0 (0-0) mm Hg*min with tight BP control. The fraction of time with MAP >85 mm Hg was 0.52 (0.25) and 0.87 (0.15). Antihypertensive medications were restarted 2 (1-3) days later in tight BP control cases. However, postoperative SBPs were similar. CONCLUSIONS: Tight BP management markedly increased intraoperative MAP and reduced the amount of hypotension. In contrast, delaying chronic antihypertensive medications had little effect on postoperative SBP. The full trial appears feasible and remains necessary but should not include postoperative antihypertensive management. TRIAL REGISTRATION: NCT04789733.