Effective dose of ciprofol combined with low-dose sufentanil for sedation of gastroscopy: a dose-finding study using a biased coin design.

Objective: This study aimed to determine the 90% effective dose of ciprofol combined with 5 µg of sufentanil for sedation during gastroscopy.

Methods: This was a double-blind, single-center dose-finding study. The ciprofol dose was assigned using a biased coin design according to the response of the previous patient, except for the first one, for which the dose was 0.3 mg/kg. All patients received 5 µg of sufentanil. The criterion for successful sedation was gastroscope insertion without choking, coughing, or body movement. If the sedation of the previous patient was unsuccessful, the dose for the next patient was increased by 0.05 mg/kg; if the sedation of the previous patient was successful, the next dose was reduced by 0.05 mg/kg or remained the same according to the biased coin result. The 90% effective dose was obtained using isotonic regression (the 95% confidence interval was obtained using the bootstrapping method) as the primary method, and the results were obtained using probit regression as a sensitivity analysis.

Results: Fifty-three patients were included in this study. Patients were assigned to one of four dose groups using a biased coin toss: group A (0.30 mg/kg), group B (0.35 mg/kg), group C (0.40 mg/kg) or group D (0.45 mg/kg). The 90% effective dose was 0.367 (95% CI: 0.344-0.416) mg/kg according to isotonic regression and 0.368 (95% CI: 0.347-0.419) mg/kg according to probit regression. The differences in the incidence of hypotension, mean arterial pressure and heart rate among the dose groups were not statistically significant. However, there was a statistically significant decrease in the mean arterial pressure and heart rate (P < 0.05) after the administration of ciprofol.

Conclusion: The 90% effective dose of ciprofol combined with 5 µg of sufentanil for sedation during gastroscopy was determined to be 0.367 (95% CI: 0.344-0.416) mg/kg. Within the dose range of 0.3-0.45 mg/kg, ciprofol reduced the mean arterial pressure and heart rate in patients, but these effects were not dose-dependent.