Purpose: To compare the efficacy of intranasal dexmedetomidine and dexmedetomidine-ketamine premedication in preschool children undergoing tonsillectomy.
Patients and Methods: We enrolled 66 children with American Society of Anesthesiologists physical status I or II, aged 3– 7 years undergoing tonsillectomy. Patients were randomly allocated to receive intranasal premedication with either dexmedetomidine 2 μg kg^{− 1} (Group D) or dexmedetomidine 2 μg kg^{− 1} and ketamine 2 mg kg^{− 1} (Group DK). The primary outcome was the sedation level assessed by the Modified Observer’s Assessment of Alertness/Sedation Scale (MOAA/S) 30 min after intervention. The minimal clinically relevant difference in the MOAA/S score was 0.5. Secondary outcomes included sedation onset time, parental separation anxiety, acceptance of mask induction, emergence time, emergence delirium, postoperative pain intensity, length of stay in the post-anesthesia care unit (PACU), and adverse effects.
Results: At 30 min after premedication, the MOAA/S score was lower in Group DK than in Group D patients (median: 1.0, interquartile range [IQR]: 1.0– 2.0 vs median: 3.0, IQR: 2.0– 3.0; P < 0.001), with a median difference of 1.0 (95% confidence interval [CI]: 1.0– 2.0, P < 0.001). Patients in Group DK showed considerably faster onset of sedation (15 min, 95% CI: 14.2– 15.8 min) than Group D (24 min, 95% CI: 23.2– 24.8 min), with a median difference of 8.0 min (95% CI: 7.0– 9.0 min, P < 0.001). Both parental separation and facemask acceptance scores were lower in Group DK than in Group D patients (P =0.012 and P =0.001, respectively). There was no significant difference in emergence time, incidence of emergence delirium, postoperative pain scores, and length of stay in the PACU between the two groups.
Conclusion: Intranasal premedication with a combination of dexmedetomidine and ketamine produced better sedation for pediatric tonsillectomy than dexmedetomidine alone.
Keywords: preoperative sedation, mask induction, pediatric anesthesia