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).