Low-Dose Alfentanil Effectively Reduces the ED50 of Remimazolam for Loss of Consciousness in Pediatric Patients...

To investigate the effects of low-dose alfentanil on the 50% effective dose (ED₅₀)/95% effective dose (ED₉₅) of remimazolam for successful loss of consciousness during general anesthesia in pediatric patients.

Fifty-two pediatric patients (aged 3-12, ASA I-II) scheduled for elective surgery were divided into two groups: Group A (n=24;alfentanil 5 μg kg^-1 + remimazolam 0.1 mg kg^-1) and Group C (n=28;saline + remimazolam 0.15 mg kg^-1). The MOAA/S scale was employed for assessment. To calculate the ED50, ED95 of remimazolam for inducing loss of consciousness in pediatric patients undergoing general anesthesia. Record the monitored values (MAP, HR, SpO₂) at different time points and the incidence of injection pain, hiccups, spontaneous movements, hypotension, bradycardia, respiratory depression, and overall adverse events.

In Group A, the ED₅₀ of remimazolam for loss of consciousness in pediatric patients was 0.212 mg kg^-1 (95% CI: 0.182 - 0.242 mg kg^-1), significantly lower than that in Group C (0.340 mg kg^-1, 95% CI: 0.295-0.388 mg kg^-1, P <0.001). Similarly, the ED₉₅ in Group A was 0.265 mg kg^-1 (95% CI: 0.237-0.413 mg kg^-1), significantly lower than that in Group C (0.434 mg kg^-1, 95% CI: 0.387-0.737 mg kg^-1, P <0.001). The overall incidence of adverse reactions was 8.3% in Group A, significantly lower than the 39.3% in Group C (P = 0.012). Compared with baseline values at T0, the MAP of pediatric patients in both groups decreased at T2 (P<0.05), but the reduction remained within 20% of the baseline values.

Low-dose alfentanil (5 μg kg^-1) significantly reduces the ED₅₀ and ED₉₅ of remimazolam for successful loss of consciousness during paediatric general anaesthesia induction and decreases the incidence of adverse reactions during remimazolam induced sedation.