Purpose  The objective of this study was to evaluate the efficacy and safety of buccal dexmedetomidine as a preanesthetic in children, to compare it with diazepam, and to investigate the optimal dosage for buccal dexmedetomidine administration by measuring its serum concentration.

Methods  We performed a prospective study with 40 children who were assigned to two groups. The patients underwent an operation for inguinal or umbilical hernia. Twenty children received dexmedetomidine buccally at 3–4 μg/kg (Dex Group) and 20 received a diazepam suppository at 0.7 mg/kg (Diazepam Group) as preanesthetics 1 h before the operation. Heart rate, systolic blood pressure, SpO₂, and respiratory rate were measured 1 h after premedication in all children. Sedation level was preoperatively evaluated, and compared with the Ramsay score, in the ward, at the entrance to the main operating rooms, and at anesthesia induction between the two groups. To investigate the optimal dosage of buccal dexmedetomidine, we compared the mean serum concentration of dexmedetomidine at induction between patients with a Ramsay score of 5 or greater and those with a Ramsay score less than 5. The Mann–Whitney U test was used for statistical analysis.

Results  There was no significant difference between the two groups in age or body weight. Furthermore, there was no significant difference between the two groups in heart rate, systolic blood pressure, SpO₂, or respiratory rate after administration of either medication. The Ramsay score of the Dex Group was significantly higher than that of the Diazepam Group at all times. The mean serum dexmedetomidine concentration at induction in patients with a Ramsay score of 5 or greater (75 ± 50 pg/ml) was significantly higher than in those with a Ramsay score less than 5 (34 ± 36 pg/ml, P < 0.05).

Conclusion  These results suggest that the buccal administration of dexmedetomidine (3–4 μg/kg) 1 h before the operation can be safely and effectively applied as a preanesthetic in children.