浅低温体外循环对心脏手术婴幼儿患者罗库溴铵药效学的影响

Effects of cardiopulmonary bypass with mild hypothermia on pharmacodynamics of rocuronium in infants undergoing cardiac surgery

目的探讨浅低温体外循环（cPB）对心脏手术婴幼儿患者罗库溴铵药效学的影响。方法择期行房间隔缺损修补术或室间隔缺损修补术的患儿50例，年龄6月-3岁，体重6—15kg，NY—HA心功能分级和AsA分级均为Ⅰ或Ⅱ级。采用随机数字表法，将患儿随机分为2组（n=25）：深低温组和浅低温组。深低温组CPB过程中将目标温度设定为28～30℃，浅低温组CBP过程中将目标温度设定为32．34℃。静脉注射咪达唑仑0．1ms／kg、异丙酚2mg／kg和芬太尼6-8μg／kg麻醉诱导，启动肌松监测，定标稳定后静脉注射罗库溴铵600μg／kg，当丑达最大抑制时行气管插管，机械通气，维持PETCO2 30～40mmHg。间断静脉注射芬太尼和咪达唑仑维持麻醉。术中当T1恢复至基础值的75％时，静脉注射罗库溴铵200μg／kg。分别于CPB前、CPB期间和CPB结束后，记录罗库溴铵起效时间、无反应期、临床作用时间和恢复指数。结果与深低温组比较，浅低温组CPB期间起效时间、无反应期和临床作用时间缩短（P〈0．05）。结论与深低温CPB相比，浅低温CPB可缩短心脏手术婴幼儿患者罗库溴铵的起效时间和作用时间。

Objective To investigate the effects of cardiopulmonary bypass （CPB） with mild hypothermia on the pharmacodynamics of rocuronium in infants undergoing cardiac surgery. Methods Fifty ASA I or II and NYHA class I or II infants, aged 6 months-3 yr, weighing 6-15 kg, undergoing repair of ventricular septal defect or atrial septal defect under CPB, were randomly divided into 2 groups （n = 25 each）： profound hypothermia group and mild hypothermia group. The target temperature was controlled at 28-30 ℃ during CPB in profound hypethermia group, and at 32-34℃ during CPB in mild hypothermia group. Neuromuscular block was assessed by TOF-stimulation of ulnar nerve using with TOF-Watch accelerometer. Anesthesia was induced with midazolam 0.1 mg/kg, propofol 2 mg/kg, fentanyl 6-8 μg/kg and rocuronium 600 μg/kg, and maintained with intermittent iv boluses of fentanyl and midazolam. The patients was tracheal intubated and mechanically ventilated when the maximal depression of T1 was achieved. PET CO2 was maintained at 30-40 mm Hg. When T1 returned to 75 % of the control twitch, rocuronium 200μg/kg was injected intravenously. The onset time, maximal N-M block time, clinical muscle relaxation time, and recovery index were recorded before CPB, during CPB and after CPB. Results Compared with profound hypothermia group, the onset time, maximal N-M block time and clinical muscle relaxation time were significantly shortened during CBP in mild hypothermia group （ P 〈 0.05）. Conclusion Compared with profound hypothermic CBP, mild hypothennic CBP can shorten the onset time and muscle relaxation time of rocuronitun in infants undergoing cardiac surgery.