机械通气对室间隔缺损修补术婴儿血流动力学的影响

Effect of mechanical ventilation on hemodynamics of infants undergoing ventricular septal defect repair

目的分析婴儿室间隔缺损术中,不同机械通气下,脑血流动力学与体循环血流动力学的变化及其关系。方法择期行室间隔缺损修补术婴儿83例,随机分为传统组(T组,34例)和调控组(C组,49例)。诱导插管后维持T组呼气末二氧化碳分压(PetCO2)于30～35 mmHg,C组40～45 mmHg。应用血流动力学监测仪(Mostcare)监测体循环,应用经颅多普勒超声(TCD)监测脑循环,于麻醉诱导后(T1)、开心包(T2)、体外循环结束(T3)、改良超滤结束(T4)、术毕(T5)分别记录右侧大脑中动脉脑血流速度(CBFV)及搏动指数(PI)、阻力指数(RI)并记录收缩压(Psys)、舒张压(Pdia)、重脉压(Pdic)、心率(HR)、心指数(CI)、全身血管阻力指数(SVRI)、脉压变异度(PPV)、心脏循环效率(CCE)和最大压力梯度(dp/dt)。根据潮气量(Vt/kg)和呼吸频率(F),计算每分钟通气量(Mv/kg)。结果组间比较,除T3点外,C组脑血流速度平均值(Vmean)明显高于传统组(P <0.05)。组内比较,两组患儿CBFV、Psys、Pdia、Pdic、CI在T3点明显低于其他各点,PI、RI、SVRI、PPV在T3点明显高于其他各点(P <0.05)。结论在婴儿室间隔缺损修补术中,与体循环血流动力学相比,机械通气的变化对脑血流速度的影响更为明显,调控组脑血流动力学优于传统组。

Objective To analyze the changes of cerebral hemodynamics and systemic hemodynamics in infants with ventricular septal defect during operation under different mechanical ventilation. Methods 83 infants undergoing ventricular septal defect repair were randomly divided into traditional group(group T,34 cases) and control group(group C,49 cases). End expiratory partial pressure of carbon dioxide(PetCO2)was maintained at 30 35 mmHg in group T and 40-45 mmHg in group C after induction and intubation. Hemodynamic monitor(Mostcare) was used to monitor systemic circulation and transcranial Doppler ultrasound(TCD) was used to monitor ce rebral circulation. After anesthesia induction(T1), pericardium(T2), end of cardiopulmonary bypass(T3), modified ultrafiltration(T4) and end of operation(T5), cerebral blood flow velocity(CBFV), pulsatility index (PI), resistance index(RI) of right middle cerebral artery were recorded. Recorded systolic pressure( Psys), dia stolic pressure( Pdia), severe pulse pressure( Pdic), heart rate(HR), cardiac index( CI), systemic vascular re sistance index(SVRI), pulse pressure variability(PPV), cardiac circulation efficiency(CCE) and maximum pressure gradient(dp/dt). According to tidal volume(V t/kg) and respiratory frequency(F), the ventilation vol ume per minute( Mv/kg) was calculated. Results The mean value of cerebral blood flow velocity(V mean) in group C was significantly higher than that in traditional group except T3(P<0.05). Compared with other points,CBFV, Psys,Pdia,Pdic and CI of the two groups were significantly lower at T3,PI,RI,SVRI and PPV were significant ly higher at T3 than other points(P<0.05). Conclusion Compared with systemic hemodynamics,m echanical ventilation has a more significant effect on cerebral blood flow velocity in infant ventricular septal defect repair. The cerebral hemodynamics in the control group is better than that in the traditional group.