浅低温体外循环中搏动灌注对儿童脑血流的影响

目的评价浅低温体外循环中搏动灌注对儿童脑血流的影响。方法 30例儿童随机分为搏动组(P组,15例)和非搏动组(NP组,15例)。主动脉阻断期间,P组给予搏动灌注,NP组给予非搏动灌注;主动脉开放期间,两组均予以非搏动灌注。采用经颅多普勒检测麻醉后(T1)、体外循环开始(T2)、主动脉阻断后10 min(T3)、主动脉开放后3 min(T4)、体外循环结束(T5)、手术结束(T6)时大脑中动脉收缩期峰值流速(Vs)、舒张期末流速(Vd)、平均流速(Vm),记录搏动指数(PI)和阻力指数(RI)。结果在T3和T4,P组Vs、PI、RI显著高于NP组(P0.05),两组Vd与Vm没有显著差异。在T5,P组Vd与Vm显著高于NP组(P0.05),而PI与RI显著低于NP组(P0.05),两组Vs没有显著差异。在T6,两组脑血流流速、PI、RI均没有显著差异。结论搏动灌注增加浅低温体外循环后短期内脑血流量,维持脑血管顺应性,可能具有脑保护作用。

The effect of pulsatile perfusion on cerebral blood flow in pediatric cardiac surgery

OBJECTIVE To evaluate the pulsatile flow effect on cerebral blood flow in infants undergoing cardiac surgery with mild hypothermic cardiopulmonary bypass（CPB）.METHODS Thirty infants scheduled for open-heart surgery were divided randomly into pulsatile group（Group P,n=15） and non-pulsatile group（Group NP,n = 15）.In Group P,pulsatile perfusion was applied during aortic cross-clamping period,whereas non-pulsatile perfusion was used in Group NP.Systolic peak velocity（Vs）,end of diastolic velocity（Vd）,mean velocity（Vm） as well as pulsatility index（PI） and resistance index（RI） of the middle cerebral artery were measured by transcranial doppler（TCD） after anesthesia（T1）（baseline）,at the beginning of CPB（T2）,10 minutes after aortic cross-clamping（T3）,3 minutes after declamping（T4）,at the cessation of CPB（T5）,and at the end of the operation（T6）.RESULTS At T3 and T4,Vs in Group P was significantly higher than that in Group NP.However,Vd and Vm did not show any statistical differences.PI and RI in Group P were also higher than those in Group NP（both P0.05）.At T5,Vd and Vm were significantly higher in Group P（P0.05）,whereas Vs did not show significant difference between two groups.Additionally,PI and RI in Group P were significantly lower than those in Group NP（P0.05）.However,at T6,none of cerebral blood velocities,PI and RI were different in both groups.CONCLUSION Pusatile perfusion could increase cerebral blood flow and decrease cerebral vascular resistance in early period after mild hypothermic CPB,and may be useful for cerebral protection.