Abstract: PURPOSE: To investigate the effect of different timing of dexmedetomidine administration in children's dental caries treatment under general anesthesia. METHODS: One hundred and twenty children scheduled for caries treatment were randomly divided into group D1, group D2 and group D3 with 40 cases in each group. Sevoflurane 1.5 Mac was used to maintain anesthesia in all children. Group D1 was not given dexmedetomidine. Group D2 was given 0.5 μg/(kg·h)dexmedetomidine for 10 min after intubation. Group D3 was given 0.5 μg/(kg·h) dexmedetomidine for 10 min before the end of operation. HR and MAP at the time of entering the operation room (T0), beginning of operation(T1), HR and MAP 1 hour after beginning of operation(T2) and ending of operation(T3) were measured; extubation time and recovery time were recorded; the anesthesia recovery agitation score (PAED) and pain score (FLACC) were calculated after entering the anesthesia treatment unit (PACU). SPSS 21.0 software package was used to analyze the data. RESULTS: HR and MAP at T1, T2 and T3 were significantly lower than those at T0(P<0.05). Compared with group D1, HR and MAP at T1, T2 and T3 were significantly decreased in group D2(P<0.05). Compared with group D1, HR and MAP at T3 in group D3 decreased significantly(P<0.05). The extubation time and recovery time of group D1 and D2 were significantly shorter than those of group D3(P<0.05). Compared with group D1, PAED and FLACC in group D2 and D3 were significantly lower than those in group D1(P<0.05). CONCLUSIONS: Dexmedetomidine 0.5 μg/(kg·h) pumped for 10 min after anesthesia induction intubation can stabilize the hemodynamics during operation, reduce agitation of anesthesia recovery, and do not affect the time of anesthesia recovery and extubation, which is a more reasonable time for clinical medication.

Key words: Dexmedetomidine, Caries, Children