The median effective dose of ciprofol combined with sufentanil in suppressing the laryngeal mask airway insertion response in both young and older adult patients.

Background: Ciprofol, a novel intravenous anesthetic, exhibits similar sedation mechanisms and pharmacokinetic properties to propofol. However, ciprofol demonstrates greater potency and is associated with reduced injection pain compared to propofol. Given the varying sensitivities to anesthetic agents across different age groups, this study aims to determine the median effective dose (ED₅₀) of ciprofol required to suppress the laryngeal mask airway (LMA) insertion response in both young and older adult patients, as well as to assess its potential adverse reactions.

Methods: In this study, 46 patients scheduled for surgery under general anesthesia with LMA insertion were recruited. Upon entering the operating room, patients were intravenously administered ciprofol (0.4 mg·kg^- 1) and sufentanil (0.3 µg·kg^- 1), followed by LMA insertion after three minutes. To derive robust confidence intervals for both ED₅₀ and ED₉₅, we performed an analysis using a logistic regression model combined with bootstrap resampling.

Results: In the young adult group, the ED₅₀ and ED₉₅ of ciprofol for suppressing the LMA insertion response were 0.38 mg·kg^- 1 (95% CI, 0.35-0.41) and 0.46 mg·kg^- 1 (95%CI, 0.40-0.56), respectively. In the older adult group, the respective ED₅₀ and ED₉₅ were 0.29 mg·kg^- 1 (95% CI, 0.26-0.32) and 0.37 mg·kg^- 1 (95% CI, 0.30-0.78). Regarding adverse reactions, although there were differences in the incidence of injection pain, hypotension, and bradycardia between the young and older groups, no statistically significant differences were observed between the two groups.

Conclusion: In this study, significant differences were observed in the ED₅₀ of ciprofol for suppressing the LMA insertion response between young and older adult patients. The ED₅₀ of ciprofol for young adult patients was 0.38 mg·kg^- 1 (95% CI, 0.35-0.41), while for older adult patients it was0.29 mg·kg^- 1 (95% CI, 0.26-0.32).

Trial registration: This study was registered on February 17, 2024, with the China Clinical Trial Registration Center ( www.chictr.org.cn ; Registration Number: ChiCTR2400080891).