Abstract
BACKGROUND: Hemodynamic instability during colonoscopy sedation remains a significant clinical concern. Esketamine's sympathomimetic properties may protect against these risks while reducing sedative requirements. Hence, we aim to evaluate the efficacy and safety of esketamine in improving intraprocedural sedation during colonoscopy. METHODS: We systematically searched PubMed, Scopus, CENTRAL, and Web of Science until June 2025 for randomized controlled trials. The primary outcome was the incidence of intraprocedural hypotension; secondary outcomes included bradycardia, hypoxemia, and recovery parameters. Dichotomous outcomes were pooled using risk ratios (RR) and continuous outcomes using standardized mean differences (SMD), with heterogeneity assessed via I² statistics. PROSPERO ID: CRD420251105691. RESULTS: Five randomized controlled trials comprising 858 patients were included in our analysis. Esketamine significantly reduced the risk of intraprocedural hypotension (RR: 0.34, 95% CI 0.22-0.53; I²=58%) and the incidence of hypoxemia (RR: 0.38, 95% CI 0.19-0.73; I²=0%). A reduction in injection pain was also observed (RR: 0.42, 95% CI 0.19-0.97; I²=80.5%), though this finding showed sensitivity in leave-one-out analysis. No significant differences were found between groups in bradycardia risk (RR: 0.51, 95% CI 0.23-1.14), total propofol requirement (SMD: -0.23, 95% CI -0.50 to 0.04), induction time, or procedure duration. The reduction in hypotension remained robust in sensitivity analyses. CONCLUSION: Esketamine significantly enhanced hemodynamic stability and reduced sedative demand during colonoscopy without delaying recovery, supporting its use in high-risk patients.