脑血流速度对外伤性脑梗塞的预测作用

目的观察重型颅脑外伤术后脑血流动力学指标的时程变化规律，揭示脑血流动力学指标对外伤性脑梗塞的预测价值。方法选取重型颅脑外伤术后患者104例，正常对照组40例，TCD检测大脑前、中、后动脉平均血流速度，对数据进行相关统计分析。结果重型颅脑外伤术后第1天大脑中、前、后动脉平均血流速度明显升高，第3天到达高峰，后逐渐下降，经Mann—Whitney U检验，5个时间点的平均血流速度均显著高于对照组（P〈0．001）。重型颅脑外伤术后第1天、第3天、第5天、第7天和第14天，脑梗塞组大脑前、中、后动脉平均血流速度均明显高于非脑梗塞组（P〈0．05）。ROC曲线辨别了大脑巾、前、后动脉平均血流速度的判定界值，对预测重型颅脑外伤术后外伤性脑梗塞有较高的灵敏度和特异度。大脑中动脉平均血流速度的曲线下面积显著大于大脑前、后动脉平均血流速度的曲线下面积（P〈0．05）。结论脑血管痉挛是颅脑外伤继发性脑损伤的重要危险因素．参与外伤性脑梗塞的病理生理机制，大脑动脉平均血流速度，特别是大脑中动脉平均血流速度可早期预测外伤性脑梗塞的发生．可指导临床，降低颅脑外伤的死亡率和致残率。

Predictive value of cerebral blood velocity for traumatic cerebral infarction

Objective To observe the serial change of postoperative mean blood velocity in the patients with severe traumatic brain injury, and to determine the predictive value of mean blood velocity for occurrence of traumatic cerebral infarction. Methods 104 severe traumatic brain injury patients that have undergone surgical procedures and 40 healthy controls were included in this study. The mean blood velocities of anterior, middle and posterior cerebral arteries were determined by TCD uhrasonography. All data were analyzed statistically. Results Postoperationally,the mean blood velocities of anterior,middle and posterior cerebral arteries in patients with severe traumatic brain injury increased during the 24-hour period immediately,peaked in 3 days,decreased gradually thereafter,and were substantially higher than that in healthy controls during the 14-day period （P〈0.001）. The mean blood velocities of anterior,middle and posterior cerebral arteries in patients with traumatic cerebral infarction were statistically significantly higher than those in patients without traumatic cerebral infarction （P〈0.05）. A receiver operating characteristic curve identified cutoff levels of mean blood velocities of anterior,middle and posterior cerebral arteries that predicted occurrence of traumatic cerebral infarction with the high sensitivity and specificity values （P〈0.05）. Area under curve of mean blood velocity of middle cerebral artery was statistically significantly larger than those of anterior and posterior cerebral arteries （P〈0.05）. Conclusion Cerebral arterial vasospasm may play an important role in secondary brain injury after head trauma, and can be involved in pathophysiology of traumatic cerebral infarction. The mean blood velocity of cerebral arteries, especially middle cerebral artery,can predict occurrence of traumatic cerebral infarction.