彩色多普勒超声监测猪脑死亡状态下肝脏早期血流动力学变化的初步研究

摘要

Objective To explore hepatic hemodynamic changes and relative factors in the early stage of brain death by color Doppler flow imaging (CDFI) on pig.Methods 12 Ba-ma pigs were established brain death model by respiration and circulation supports and maintained for 12 hours,using the improved slow intracranial pressure method.Pigs before brain death as the control group,after the brain death as the experimental group,blood pressure,heart rate and liver blood flow parameters were motored in the former,0h,3h,6h,9h after brain death,including portal venous velocity (PV) and portal venous flow (PVF),hepatic artery systolic velocity (S),diastolic velocity (D),hepatic artery resistance index (RI),hepatic artery S/D,hepatic artery pulsatility index (PI),hepatic vein flow velocity (V).Compare the difference between the groups and the correlation with blood pressure and heart rate.Results (1) Compared with the control group,the systolic and diastolic blood pressure were significantly lower in the brain each death group,the difference between 9h and 0h in systolic blood pressure was statistically significant (P＜0.05).(2) Compared with control group,RI,S/D,PI were increased in each experimental group and PV was decreased in 3h and 6h group (P＜0.05).(3) PV and systolic blood pressure were positively correlated (P＜0.05).Conclusions In the early stage of brain death,the pigs sustained hypotension,and there was a significant change in the hepatic hemodynamics,PV shows a significant reduction,the systolic velocity and RI of hepatic artery increased.Therefore,the relative resistance parameters of the hepatic artery were more sensitive than the hepatic artery in the early stage of liver disease after brain death.%目的 探讨多普勒超声技术(CDFI)监测猪脑死亡状态下,肝脏早期血流动力学变化及其相关因素.方法 巴马香猪12头,应用改进缓慢间断颅内加压法建立脑死亡模型,通过呼吸、循环支持维持脑死亡状态12 h.脑死亡前为对照组,脑死亡后为实验组,于脑死亡前、死亡0、3、6、9h监测血压、心率及肝脏血流参数:门静脉流速(PV)、血流量(PVF)、肝动脉收缩期流速(S)、舒张期流速(D)、肝动脉阻力指数(RI)、肝动脉S/D值、肝动脉搏动指数(PI)、肝静脉流速(V).比较各组间差异及与血压、心率的相关性.结果 (1)脑死亡各组收缩压及舒张压均较对照组降低,脑死亡9h组收缩压与0h组相比降低,均有显著性差异(P＜0.05).(2)脑死亡3、6h组PV较对照组降低,脑死亡各组RI、S/D及PI较对照组升高,均有显著性差异(P＜0.05);脑死亡组内各时间点血流动力学参数间差异无统计学意义(P＞0.05).(3)收缩压与PV呈正相关(P＜0.05).结论 脑死亡状态下,机体早期表现为持续低血压;早期肝脏血流动力学即有明显变化,低血压所致低灌注导致门脉流速减低较为显著,肝动脉流速及相关阻力参数增高,肝动脉的相关阻力参数对肝脏早期病生理的改变较肝动脉流速更为灵敏.