Cipepofol for adjunctive sedation during neuraxial anesthesia: a study protocol for a randomized controlled trial

BACKGROUND: Cipepofol is a novel 2,6-disubstituted phenol derivative increasingly used for anesthesia and sedation during gastrointestinal endoscopy and fiberoptic bronchoscopy. This study aimed to evaluate the efficacy and safety of cipepofol for adjunctive sedation during neuraxial anesthesia, thereby providing evidence for its clinical application. METHODS: This was a randomized, double-blind, non-inferiority trial. Eligible patients were randomly assigned in a 1:1 ratio to either the cipepofol group or the propofol group using a random number table. The target sedation level was defined as a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 3-4. Patients allocated to the cipepofol group received an intravenous loading dose of 0.1 mg/kg cipepofol administered over 30 ± 10 s, followed by a continuous infusion initiated at 0.3 mg/kg/h to achieve the target sedation level. Those in the propofol group received an intravenous loading dose of 0.5 mg/kg propofol administered over 30 ± 10 s, followed by a continuous infusion initiated at 1.5 mg/kg/h. The primary outcome was the sedation success rate. Secondary outcomes included the following: the percentage of total study drug administration time during which MOAA/S scores were maintained at 3-4, 1-2, or 5, respectively; time from the start of the intravenous loading dose to the first occurrence of MOAA/S score < 4, and the proportion of subjects achieving MOAA/S score < 4 within 3 min; proportion of subjects requiring rescue sedation; the vital signs of subjects; number of dose adjustments and total sedative drug consumption; time from discontinuation of the study drug infusion to the first postoperative MOAA/S score of 5, length of stay in the post-anesthesia care unit (PACU), and recovery status at PACU discharge; satisfaction levels of the anesthesiologist, surgeon, and subjects. DISCUSSION: The purpose of this study is to evaluate the efficacy and safety of cipepofol as an adjunct sedative during neuraxial anesthesia. If cipepofol demonstrates beneficial properties comparable to propofol for adjunctive sedation during neuraxial anesthesia, it could serve as a viable clinical alternative. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2500102635. Registered on 16 May 2025, www.chictr.org.cn. Prospectively registered.