不同剂量右美托咪定对室间隔缺损修补术患儿脑氧代谢的影响

Effects of different doses of dexmedetomidine on cerebral oxygen metabolism in pediatric patients with ventricular septal defect repair

目的观察不同剂量右美托咪定对室间隔缺损修补术患儿脑氧代谢的影响。方法 120例室间隔缺损修补术患儿随机分为4组,A、B、C组分别于麻醉诱导前10 min靶控输注右美托咪定0.3、0.5、0.7μg/kg,D组作为对照组,泵注等量生理盐水;泵注完毕后四组均行麻醉诱导,术中维持脑电双频指数(BIS)40~60。记录四组患者围术期不同时刻血流动力学相关指标变化,并于不同时刻抽取患者颈内静脉球部血及桡动脉血行血气分析,计算动脉-颈内静脉球部血氧差(AV-DO2)及脑氧摄取率(c O2ER)。结果 B组、C组气管插管后、开胸后5 min、转流结束时刻的MAP低于D组、A组(P<0.05)。A组、B组、C组气管插管后、开胸后5 min、转流5 min、转流结束时刻及手术结束即刻AV-DO2及c O2ER均低于D组(P<0.05)。B组非转流期间不良反应低于C组、D组(P<0.05),不良反应发生率更低。结论右美托咪定可降低室间隔缺损修补术患儿AV-DO2及c O2ER,且其作用在一定范围内随着剂量增加而降低,但泵注0.5μg/kg右美托咪定血流动力学更稳定,且不良反应较少。

Objective To observe the effects of different doses of dexmedetomidine on cerebral oxygen metabolism of children with ventricular septal defect repair. Methods Totally 120 pediatric patients with ventricular septal defect repair were enrolled in the study. They were divided into 4 groups randomly. Patients in group A,group B and group C were given target controlled infusion of 0. 3,0. 5 and 0. 7 μg/kg of dexmedetomidine respectively at 10 min before induction of anesthesia; group D（ control group） received infusion of saline. All the patients received anesthesia induction,and the bispectral index（ BIS） was maintained in the range of 40 ~ 60 during operation. The changes in hemodynamic indexes were recorded during perioperative period. The cerebral arteriovenous oxygen content difference（ AV-DO2） and cerebral oxygen extraction ratio（ c O2ER） were calculated by analyzing the radial arterial and jugular venous bulb blood samples. Results The MAP in group B and group C after tracheal intubation,at 5 min after cutting breast bone and after flowwas lower than that of group D and group A,and the HR in group B and group C was lower than that of group D（ P〈0. 05）; the AV-DO2 and c O2 ER after tracheal intubation,at 5 min after cutting breast bone and immediately after flowand surgery in group D were higher than those of the other groups（ P〈0. 05）. The adverse reaction rate in group B was lower than that of group C and group D（ P〈0. 05）. Conclusion Dexmedetomidine can decrease the AV-DO2 and c O2 ER of pediatric patients with ventricular septal defect repair,which is reduced with the increase of dose within a certain range. Infusion of 0. 5 μg/kg of dexmedetomidine has more stable hemodynamics and lower adverse reaction rate.