小儿心内直视手术中心肺转流对雷米芬太尼药代动力学的影响

目的探讨心内直视手术中心肺转流(CPB)对雷米芬太尼药代动力学的影响。方法择期CPB下行心内直视手术的患儿40例,静脉注射雷米芬太尼后1、2、3、4、5、10、15、20、25、30、45、60、90、120、180min及其后每隔3h直至24h各抽取桡动脉血测定血浆雷米芬太尼浓度。同时,分别在CPB前、CPB后、开放升主动脉时及拔除主动脉插管时各采取动脉血测定血浆雷米芬太尼、白蛋白、总蛋白浓度和血细胞比容(Hct)。应用NONLIN软件分析药代动力学参数。结果CPB前血浆雷米芬太尼浓度-时间衰减曲线可用三室开放模型表示,血药浓度-时间曲线拟合非常满意(r=0.9947,P<0.01)。CPB后雷米芬太尼的血药浓度显著降低(P<0.01),血药浓度-时间曲线也拟合良好(r=0.9905,P<0.01)。CPB前后药代动力学参数比较差异无统计学意义。CPB后白蛋白、总蛋白浓度和Hct均显著降低(P<0.01)。结论CPB时雷米芬太尼的血药浓度下降,但是药代动力学参数无明显改变。血液稀释是雷米芬太尼血药浓度改变的原因之一。

Effects of cardiopulmonary bypass on pharmacokinetics of remifentanil in children

Objective To study the effects of cardiopulmonary bypass on the pharmacokinetics of remifentanil in children. Methods Forty patients undergoing open-heart surgery under CPB were included in this study. Arterial blood samples were taken for detecting the concentration at 1,2,3,4,5,10,15,20,25,30,45,60,90,120,180min and every 3hours during first 24hours after injection of remifentanil. Plasma concentration of remifentanil,albumentotal protein,total protein and hematocrit were measured with NONLIN before CPB,at the termination of CPB,opening of ascending aorta,exelcymosis of aortic cannula was used to analyze the pharmacokinetic parameters. Results The plasma remifentanil concentration-time attenuation curve before CPB showed as the three-compartment open pharmacokinetics model (r=0.9947,P<0.01). The plasma concentration of remifentanil was significantly reduced after CPB,and the plasma remifentanil concentration-time attenuation curve fit well too (r=0.9905,P<0.01). There were no significant differences in pharmacokinetic parameters between before and after CPB. The plasma concentration of albumentotal protein,total protein and hematocrit were all significantly reduced after CPB(P<0.01). ConclusionThe plasma concentration of remifentanil during CPB was reduced secondary to blood dilution.,but pharmacokinetic parameters were not significantly changed.