Estimation of ED50 and ED95 of oliceridine required to suppress bronchoscopic responses during remimazolam sedation: study protocol for an up-and-down sequential allocation trial.

backgroundFlexible bronchoscopy frequently provokes airway reflexes that impair patient comfort and procedural quality. Remimazolam provides effective sedation but often requires adjunctive opioids to suppress coughing and movement. Oliceridine is a G-protein-biased μ-opioid receptor agonist that may provide effective pain relief while minimising respiratory and haemodynamic side effects. However, the optimal dose of oliceridine combined with remimazolam for bronchoscopy remains unknown. METHODS AND ANALYSIS: This is a prospective, single-centre, sex-stratified, up-and-down sequential allocation trial. Adult patients (18-65 years, American Society of Anesthesiologists I-III) undergoing painless flexible bronchoscopy will receive intravenous oliceridine followed by remimazolam (0.3 mg/kg). The initial oliceridine dose is 40 µg/kg and is adjusted in 10 µg/kg steps according to the Dixon method based on bronchoscopic response. The primary outcome is the ED50 and ED95 of oliceridine for suppressing bronchoscopic responses during remimazolam sedation in male and female patients. ED50 and ED95 values with 95% CIs will be estimated using probit regression. Secondary outcomes include respiratory and haemodynamic events, rescue medication use, recovery characteristics and satisfaction scores. ETHICS AND DISSEMINATION: Approval for the study has been granted by the Ethics Committee of Guiyang First People's Hospital. Written informed consent will be obtained from each participant. The findings will be shared through peer-reviewed journals and academic conferences.

trial registrationChiCTR2500114090.