经颅多普勒超声对脑死亡患者颅内血流动力学的观察

Observation of intracranial hemodynmrdcs in brain death through transcranial doppler ultrasound

目的 观察脑死亡患者的脑血流频谱演变过程。方法 采用经颅多普勒超声（TCD）检测脑死亡患者双侧大脑中动脉（MCA）的血流情况。结果 20例临床诊断脑死亡患者的MCA血流速度6~37 cm/s,平均（12.13±3.15）cm/s。频谱变化有振荡波（舒张期反向波）、钉子波（收缩期尖小波形）、无血流信号三种TCD特征性频谱,并随病情进展依次出现。20例患者均在出现振荡波频谱后8 d内出现心跳不可逆停止,其中有90%（18例）的患者血流频谱出现振荡波-钉子波-无血流信号的演变过程。结论 振荡波、钉子波及血流信号消失这三种规律性演变的特征性TCD血流频谱能辅助脑死亡的诊断。

Objective To observe the evolution process of cerebral blood flow spectrum in brain death by transcranial doppler ultrasound.Methods To detect the blood flow of bilateral middle cerebral artery in brain dead patients by transcranial doppler ultrasound.Results Twenty brain dead patients were collected in the study.The blood flow velocity of middle cerebral artery ranged s from 6 to 37cm/s,and the mean velocity was （12.13±3.15）cm/s.There were three characteristic spectrums which include oscillatory wave（reverse wave in diastolic）,nails wave（tip small wave in systolic）,no blood flow sign,and they appeared in turn accoerding to worsen of the disease.The heartbeat irreversibly stopped within 8 days after the appearing of oscillatory wave,and ninty percent of the cases had the regular blood flow spectrums of oscillatory wave-nails wave-no blood flow sign.Conclusion The three regularly characteristic transcranial doppler ultrasound blood flow spectrums,which include oscillatory wave,nails wave and no blood flow sign could facilitate the diagnosis of brain death.