Low-Dose Esketamine as an Adjuvant to Propofol Sedation for Same-Visit Bidirectional Endoscopy: Protocol for a Multicenter Randomized Controlled Trial

BACKGROUND: Same-visit bidirectional endoscopy (esophagogastroduodenoscopy and colonoscopy) is widely performed under sedation. At present, the optimal sedation regimen remains unclear. This study aims to test the hypothesis that a low-dose esketamine added to propofol sedation reduces hemodynamic and respiratory adverse events in these procedures. METHODS: In this multicenter, randomized, double-blind, placebo-controlled trial, 660 adult patients scheduled for same-visit bidirectional endoscopy under sedation from 3 teaching hospitals in China will be recruited. Patients will be randomly allocated, in a 1:1 ratio, to an esketamine group or a normal saline group (n = 330 in each group), stratified by study center. All patients will receive intravenous propofol 0.5 mg/kg and sufentanil 0.1 μg/mL for induction of sedation, followed by intravenous esketamine 0.15 mg/kg or the same volume of normal saline. Propofol will be titrated to the target sedation levels during the procedures. The primary endpoint is a composite of desaturation (peripheral oxygen saturation < 90%) and hypotension (systolic blood pressure <80 mmHg or decrease >30% of baseline). Secondary endpoints include desaturation, hypotension, total dose of propofol, pain scores and fatigue scores on the 0–10 numerical rating scale, dizziness or headache, hallucination or nightmare, nausea or vomiting, endoscopist satisfaction, and patient satisfaction. All analyses will be intention-to-treat. DISCUSSION: We expect that a low-dose esketamine adjunct to propofol-based sedation will improve cardiorespiratory stability in patients undergoing same-visit bidirectional endoscopy, providing reference for clinical sedation practice during these procedures. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Identifier: ChiCTR-ChiCTR2200055938).