经颅多普勒超声在早期诊断脓毒症相关性脑病中的临床意义

The clinical significance of transcranial Doppler in early diagnosis of sepsis-associated encephalopathy

目的探索经颅多普勒超声(TCD)在早期诊断脓毒症相关性脑病(SAE)的临床意义。方法选2015年7月至2016年3月中南大学湘雅医院重症医学科的脓毒症患者,收集患者入ICU24 h内的一般临床资料,每日对患者进行2次谵妄评估,以ICU谵妄评估量表(CAM-ICU)作为临床诊断SAE金标准,将患者分为SAE组和脓毒症未合并脑病组。采用TCD监测2组患者大脑中动脉收缩期峰值血流速度(Vs)、舒张末期血流速度(Vd)、平均血流速度(Vm)、搏动指数(PI)和阻力指数(RI)。分析上述各参数诊断SAE的界值、敏感度和特异度。结果43例脓毒症患者纳入本研究,其中SAE组12例,脓毒症未合并脑病组31例。SAE组患者Vm、Vd低于脓毒症未合并脑病组[Vm:(53.50±12.22)cm/s比(61.68±9.63)cm/s,P<0.05;Vd:(33.42±10.87)cm/s比(43.16±7.84)cm/s,P<0.01],但PI、RI高于脓毒症未合并脑病组[PI:(1.16±0.2)比(0.90±0.15),P<0.01;RI:(0.65±0.08)比(0.56±0.06),P<0.01]。Vd、PI、RI诊断SAE时接受者操作特征曲线下面积均>0.7,具有较高的准确性。Vd诊断SAE的界值为34.50 cm/s,敏感度为93.5%,特异度为58.3%;PI诊断SAE的界值为1.16,敏感度为58.3%,特异度为96.8%;RI诊断SAE的界值为0.65,敏感度为58.3%,特异度为96.8%。结论SAE的发病与脓毒症患者的脑灌注不足相关,TCD有利于SAE的早期诊断。

Objective To investigate the clinical significance of transcranial Doppler(TCD)in early diagnosis of sepsis-associated encephalopathy(SAE).Methods Septic patients admitted to the intensive care unit(ICU)were recruited at Xiangya Hospital,Central South University from July 2015 to March 2016.Clinical data and TCD parameters during 24 hours after admission were collected.All patients were screened for delirium using the confusion assessment method for the intensive care unit(CAM-ICU)twice a day.The gold standard of the diagnosis of SAE was positive CAM-ICU evaluation.Patients were divided into SAE group and the non-SAE group.TCD data including systolic velocity(Vs),diastolic velocity(Vd),mean velocity(Vm),pulsatility index(PI)and resistant index(RI)were analyzed to determine the optimal diagnostic cut-off value.Results A total of 43 patients were enrolled including 12 in SAE group and 31 in non-SAE group.Vm and Vd were lower in SAE group[Vm:(53.50±12.22)cm/s vs.(61.68±9.63)cm/s,P<0.05;Vd:(33.42±10.87)cm/s vs.(43.16±7.84)cm/s,P<0.01]but PI and RI were significant higher in SAE group[PI:(1.16±0.2)vs.(0.90±0.15),P<0.01;RI:(0.65±0.08)vs.(0.56±0.06),P<0.01]than in non-SAE group.The cut-off values of Vs,Vm,Vd,PI and RI for the diagnosis of SAE were 112cm/s,55.50cm/s,34.50cm/s,1.16,0.65,respectively,with the relevant sensitivities of 19.4%,83.9%,93.5%,58.3%,58.3% and the specificities of 100.0%,50.0%,58.3%,96.8%,96.8%,respectively.The diagnostic AUC of Vd,PI and RI were 0.741,0.808 and 0.808 respectively.Conclusions The parameter changes of TCD suggest that the pathogenesis of SAE is related to cerebral hypoperfusion,TCD is a helpful method for the early diagnosis of SAE.