Postoperative sedative management with dexmedetomidine after pediatric anesthesia

Objectives: Sevoflurane is widely used in pediatric anesthesia because of rapid emergence from anesthesia. However, the occurrence of emergence agitation is recognized as a common side effect after sevoflurane anesthesia in children. On the other hand, dexmedetomidine (Dex) has been used not only for postoperative sedation but also as an adjuvant in general anesthesia. We assessed an influence on respiration and circulation, and a reduction in the incidence of emergence agitation after sevoflurane anesthesia in children.

Methods: 20 pediatric patients participated in this study. General anesthesia was induced with 66% nitrous oxide in oxygen and 5% sevoflurane, and managed with 66% nitrous oxide in oxygen and 1.5~3% sevoflurane. Dex was continuously administered with 0.4 mcg/kg/h from approximate 30 minutes before the end of operations to 120 minutes after the end of operations. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), respiratory rate (RR), SpO2, Ramsay score (RS) and Richmond Agitation-Sedation score (RAS) were monitored at pre-operation (control), 30, 60, 90, 120, 150, 180, 210, 300 minutes after the end of operations. On the next day of the operation, the questionnaire from each guardian was gathered. As the statistical analysis, Friedman's test and Wilcoxon t-test were applied.

Results: There were no significant changes in SBP, DBP, HR and RR. SpO2 decreased significantly at 180 minutes after the end of operation. RS and RAS indicated significant changes from 30 minutes to 150 minutes after the end of operation.

Conclusions: Dex hardly influences respiration or circulation, however, oxygen administration should supply more than at least 30 minutes after the stop of Dex administration. It is suggested that Dex reduces the incidence of emergence agitation after sevoflurane anesthesia, because RS and RAS were in the optimal sedative range from 30 to 150 minutes after the end of operation.