Obesity Reduces the Median Effective Dose of Remimazolam in Aged 6–18 Pediatric Patients for Procedural Sedation

Background: Remimazolam, a relatively newly developed ultrashort-acting benzodiazepine agent, is utilized for procedural sedation and general anesthesia, and was recently widely used in school-aged pediatric patients. However, few data could be available in obese pediatric patients. We compared the median effective dose (ED50) of remimazolam for procedural sedation in pediatric obese and normal weight patients based on the hypothesis that obese pediatric patients require a lower dose per body weight. Methods: Sixty pediatric patients were enrolled and allocated into the normal weight group (Group N) and the obese group (Group O). For the first pediatric patient, remimazolam was administered at an initial dose of 0.2 mg/kg. Subsequent doses were adjusted in increments of ± 0.02 mg/kg, with an increase if the preceding dose was ineffective or a decrease if it achieved the desired effect, following a sequential up-and-down design. ED50 was estimated and compared using this approach. Results: The ED50 of remimazolam was significantly lower in Group O 0.17 mg/kg (95% CI: 0.14– 0.19 mg/kg) than in Group N 0.23 mg/kg (95% CI: 0.19– 0.24 mg/kg) ( P < 0.001). The estimated relative median potency was 0.74 (95% CI: 0.41– 0.91) via probit analysis. Conclusion: In summary, when administered in combination with remifentanil at a dosage of 2 μg/kg, the ED50 value for inducing sedation with remimazolam is reduced by approximately 26% in obese paediatric patients compared to normal-weight children.