Preventing intraoperative hypotension in propofol-sedated gastroenteroscopy: a randomized trial of crystalloid preloading.

BACKGROUND: Intraoperative hypotension (IOH) is common during propofol-sedated gastroenteroscopy, yet preventive strategies in outpatient settings remain limited. We evaluated whether crystalloid preloading reduces IOH. METHODS: In this prospective randomized clinical trial, 606 patients were assigned to receive crystalloid preloading (10 mL/kg lactated Ringer's over 25 min) or no preprocedural fluid. The primary outcome was the incidence of IOH. Secondary outcomes included Inferior Vena Cava Collapsibility Index (IVC-CI), vasopressor use, recovery time, and adverse events. RESULTS: Six hundred and six participants were randomized into two groups, and 522 completed the trial per protocol. IOH occurred in 14.2% (43/303) of patients in the Preload group versus 25.4% (77/303) in the Control group (risk ratio = 0.56; 95% CI 0.40-0.78; P < 0.001), corresponding to an absolute risk reduction of 11.2% (number needed to treat=9). Preloading reduced ΔIVC-CI and ephedrine use (both P < 0.05). Propofol use, recovery time, procedure duration, and adverse events were similar between groups. CONCLUSIONS: Crystalloid preloading reduces the incidence and severity of IOH during propofol-sedated gastroenteroscopy without increasing adverse events. This simple strategy may improve hemodynamic stability in outpatient anesthesia.