经颅多普勒超声观察甘露醇对心肺复苏后患儿脑血流的影响

Influence of mannitol on cerebral blood flow of post-resuscitation children as detected by transcranial Doppler ultrasound

目的 应用经颅多普勒超声 (TCD)观察甘露醇对复苏后患儿脑血流动力学的影响。方法 以大脑中动脉(MCA)和颈内动脉颅外段 (EICA)为靶血管,观察 21例复苏后患儿脑血流变化的趋势及应用首剂甘露醇前后各指标的变化。据舒张期血流将患儿分为 2组:Ⅰ组为舒张期血流消失或反流(9例);Ⅱ组为舒张期血流正向(12例)。结果 Ⅰ组静注甘露醇前后MCA和EICA的收缩期峰流速(Vp)、舒张期流速(Vd)、平均流速(Vm)、脉动指数(PI)无明显改变 (P>0.05), Glasgow评分最高值明显低于Ⅱ组(P<0.05 ),随病程TCD频谱形态无改善,预后极差。Ⅱ组用药后MCA的Vd、Vm、Vp增加,PI降低 (P<0 05 );EICA的Vd增加 (P<0.05 ),Vp、Vm、PI无明显变化 (P>0.05),随病程TCD频谱形态渐趋正常,患儿全部存活。结论 脑损害较轻的患儿应用甘露醇可改善脑灌注,舒张期血流消失或反向频谱提示预后不良,与严重脑损伤密切相关,甘露醇对此类患儿难以发挥调节脑血流作用。

Objective To detect the influence of mannitol on cerebral blood flow of post- resuscitation children by transcranial Doppler (TCD).Methods The blood flow changes of left side middle cerebral artery (MCA) and extracranial internal carotid artery (EICA) were monitored by TCD in 21 post-resuscitation children . TCD waveforms, peak velocity (Vp), diastolic velocity (Vd), mean velocity (Vm) and pulsitility index (PI) of MCA and EICA were monitored daily and 30 minutes before and after the first dose of mannitol. Glasgow scores were estimated in the meantime. The patients were divided into 2 groups according to the patterns of diastolic flow. Patients in group Ⅰ showed no diastolic flow or retrograde diastolic flow (n=9), and patients in groupⅡ had positive diastolic flow (n=12).Results Vp、Vd、Vm、PI of MCA and EICA in group Ⅰ patients had no significant change after the administration of mannitol and the Glasgow scores were much lower than that of groupⅡpatients (P<0.05). TCD waveforms showed no improvement in groupⅠpatients and their outcomes were poor. Vd, Vm and Vp of MCA and Vd of EICA in group Ⅱ patients increased, PI of MCA decreased (P<0.05), while Vp, Vm, PI of EICA had no significant change. TCD waveforms recovered within one week. All the patients in this group survived. Conclusions The results suggested that mannitol could improve cerebral perfusion in patients with mild brain damage. These patients usually had increased diastolic blood flow in the early stage. Lack of or retrograde diastolic flow of TCD waveforms might be associated with severe brain damage with poor outcome. Mannitol had no effect on improving cerebral blood flow in these patients.