Objective To investigate the effect of dexmedetomidine(Dex) on arterial baroreflex function in pediatric patients undergoing general anesthesia.Methods 60 children scheduled for concealed penis correction surgery under general anesthesia were enrolled in this study.These children were randomly divided into two groups (n=30), dexmedetomidine group (group Dex) with Dex 0.5 μg/kg, then 0.4 μg/(kg·h) after 10 min until the end of surgery,and Control group (group Con) with an equal volume of saline.Baroreflex sensitivity (BRS) and hemodynamic parameters(MAP and HR)were obtained at the five periods: when patients were calmed down(T1), after the 10 minutes Dex or saline bolus infusion(T2), 5 min after placing the laryngeal mask(T3), 5 min after the start of operation(T4) and recovery end of operation (T5).Results Compared with T1, BRS had no significant difference at T2, decreased at T3~T5 in group Con(P<0.05).While BRS were significantly higher at T2 (P<0.05), decreased at T3(P<0.05) and had no significant difference at T4 and T5 in group Dex.Compared with group Con, BRS were significantly higher in group Dex at T2~T5(P<0.05).Compared with T1, MAP had no significant difference at T2, decreased at T3 and T4(P<0.05), had no significant difference at T5 in both groups.MAP had no significant difference between group Con and Dex.Compared with T1, HR had no significant difference at T2, droped at T3 and T4(P<0.05), increased at T5(P<0.05) in group Con.And HR droped at T2~T4(P<0.05), increased at T5(P<0.05) in group Dex.Compared with group Con, HR were significantly decreased in group Dex at T2~T5(P<0.05).Conclusion The results indicate that arterial baroreflex function is significantly depressed during anaesthesia in healthy surgical pediatric.Dex may improve the depressed baroreflex function throughout anaesthesia procedure, and Dex have contribute to maintain the hemodynamic stability.%目的 观察右美托咪定(Dex)对小儿全身麻醉后动脉压力感受性反射功能的影响.方法 选择60例择期全麻下行隐匿性阴茎矫治术的患儿,随机分为2组(n=30).Dex组入室后静脉泵注Dex 0.5 μg/kg,10 min后改为0.4 μg/(kg·h)维持至术毕;对照组,泵注等容量的生理盐水,其余麻醉用药相同.选择入室平静后(T1)、Dex或生理盐水负荷量泵注后即刻(T2)、置入喉罩后5 min(T3)、手术开始后5 min(T4)、术毕清醒(T5)5个时点,采集测量压力感受性反射敏感性(BRS)值和血流动力学指标(MAP和HR).结果 与T1时点相比,对照组T2时点BRS值差异无统计学意义,T3~T5时点的BRS值均降低(P<0.05);Dex组T2时点BRS值显著升高(P<0.05),T3时点BRS值降低(P<0.05),而T4、T5时点差异无统计学意义.与对照组相比,Dex组在T2~T5各时点BRS值均较高,差异有统计学意义(P<0.05).与T1相比,两组患儿的MAP在T2时点差异无统计学意义,T3、T4时间点均降低(P<0.05),T5时点差异无统计学意义;在T2~T5时点两组之间差异无统计学意义.与T1相比,对照组T2时点HR差异无统计学意义,T3, T4时点HR减慢(P<0.05),T5时点HR加快(P<0.05);Dex组T2~T4时点HR均减慢(P<0.05),T5时点HR加快(P<0.05);与对照组相比,Dex组T2~T5时点HR均降低(P<0.05).结论 全麻药物降低小儿动脉压力感受性反射功能,Dex可改善全麻药物对小儿BRS的抑制作用,有利于维持血流动力学稳定.
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