七氟烷吸入麻醉诱导期间潮气末二氧化碳分压对室间隔缺损婴儿脑血流动力学的影响

Effect of end-tidal carbon dioxide on cerebral dynamics in infants with ventricular septal defect during inhalational sevoflurane anesthesia induction

目的:比较不同浓度七氟烷吸入麻醉诱导期间,潮气末二氧化碳分压(PETCO_(2))对室间隔缺损(VSD)婴儿局部脑氧饱和度(rScO_(2))和大脑中动脉脑血流速度(CBFV)的影响。方法:本研究共纳入1岁以内VSD患儿52例,其中七氟烷高浓度(SH)组和七氟烷低浓度(SL)组各26例。分别采用1.5MAC和1.0MAC七氟烷吸入麻醉诱导插管,通过MostCare分析动脉压力波形,同时监测rScO_(2)和CBFV。调整通气参数使PETCO_(2)依次维持在30(T1)、35(T2)、40(T3)、45(T4)mmHg(1mmHg=0.133kPa)。记录各时点rScO_(2)、CBFV、搏动指数(PI)、阻力指数(RI)。结果:SH组rScO_(2)、CBFV舒张期、CBFV平均值显著高于SL组,PI、RI显著低于SL组(P<0.05)。两组患儿rScO_(2)、CBFV收缩期、CBFV舒张期、CBFV平均值均随PETCO_(2)的升高而显著增加,PI、RI显著减小(P<0.001)。PETCO_(2)与rScO_(2)、CBFV收缩期、CBFV舒张期、CBFV平均值均呈明显正相关(P<0.001),与PI、RI呈明显负相关(P<0.001)。结论:VSD患儿七氟烷吸入麻醉诱导期间,随着PETCO_(2)升高脑血流动力学有明显改善。1.0MAC和1.5MAC七氟烷吸入都可满足VSD患儿麻醉诱导,1.5MAC脑血流动力学改善更明显。

Objective:To compare the effects of end-tidal carbon dioxide partial pressure(PETCO_(2))on regional cerebral oxygen saturation(rScO_(2))and cerebral blood flow velocity(CBFV)in infants with ventricular septal defect(VSD)during inhalation induction of anesthesia with different concentrations of sevoflurane.Methods:Fifty-two infants with VSD less than 1 year old were enrolled and divided into high initial concentration sevoflurane group(SH group)and low initial concentration sevoflurane group(SL group).Each group included 26 cases.SH group was induced with 1.5 MAC sevoflurane and SL group was induced with 1.0 MAC sevoflurane.Arterial pressure waveforms were analyzed by MostCare,while rScO_(2) and CBFV were monitored in both groups.By adjusting the tidal volume(Vt)and respiratory rate(RR),PETCO_(2) was maintained at the level of 30mmHg(T1),35mmHg(T2),40mmHg(T3),or 45mmHg(T4),rScO_(2)、CBFV、PI、RI values at T1,T2,T3,and T4 were recorded respectively.Results:rScO_(2),CBFVdiastolic,and CBFVmean in the SH group were significantly higher than those in the SL group,and PI and RI were significantly lower than those in the SL group(P<0.05).In both groups,rScO_(2),CBFVsystole,CBFVdiastole,and CBFVmean value increased significantly,and PI and RI decreased significantly from T1 to T4(P<0.001).PETCO_(2) was significantly positively correlated with rScO_(2),CBFVsystole,CBFVdiastole,and CBFVmean(P<0.001),significantly negatively correlated with PI and RI(P<0.001).Conclusions:During the induction of sevoflurane inhalation anesthesia in infants with VSD,cerebral hemodynamics improved significantly as PETCO_(2) increased.Both 1.0MAC and 1.5MAC sevoflurane inhalation can satisfy the need of anesthesia induction in children with VSD,and the improvement of cerebral hemodynamics in 1.5MAC is more obvious.