Abstract:

Objective To investigate whether the predictive reliability of an increase in the mean blood flow velocity ratio of the ipsilateral to contralateral middle cerebral arteries (I/C mBFV) ≥120 cm/s is higher than that of the conventional absolute flow velocity (mBFV) for delayed cerebral ischemia (DCI) in higher modified Fisher grade. Methods Patients admitted into NICU of Beijing Tiantan Hospital, Capital Medical University from November 2011 to November 2013 who underwent transcranial Doppler sonography (TCD) and diagnosed with subarachnoid hemorrhage (SAH) ≥3 by modified Fisher grade were consecutively enrolled into study retrospectively. The mBFV value in bilateral middle cerebral arteries and I/C mBFV were recorded. The end point was delayed cerebral ischemia (DCI). The I/C mBFV and middle cerebral artery mBFV ≥120 cm/s were calculated for predicting the sensitivity, specificity, positive predictive value and negative predictive value of DCI. Results A total of 44 patients were included in the study, among which, 18 patients developed DCI, with incidence rate of 41%. For middle cerebral artery mBFV ≥120 cm/s, the sensitivity, specificity, positive predictive value and negative predictive value of TCD in predicting DCI were 77.8%, 50%,

53.8%, 75%, respectly. For I/C mBFV ≥1.5, the sensitivity, specificity, positive predictive value and negative predictive value of TCD in predicting DCI were 71.8%, 41.7%, 50%, 71.4%, respectively. Conclusion For SAH patients with higher modified Fisher grade, TCD was still an important tool for predicting DCI. The predictive value of mBFV ≥120 cm/s was higher than that of I/C mBFV ≥1.5.

Key words: Blood flow velocity; Cerebral vasospasm; Delayed cerebral ischemia;Subarachnoid hemorrhage; Transcranial Doppler

摘要：

目的 观察在高改良Fisher分级的蛛网膜下腔出血患者中双侧大脑中动脉血流速度比值（mean blood flow velocity ratio of the ipsilateral to contralateral middle cerebral arteries，I/C mBFV）对于迟发性脑 缺血（delayed cerebral ischemia，DCI）的预测价值是否高于大脑中动脉平均血流速度（mean blood flow velocity，mBFV）≥120 cm/s。 方法 回顾性连续收集2011年11月-2013年11月首都医科大学附属北京天坛医院NICU住院的改良 Fisher分级≥3级的蛛网膜下腔出血患者，所有患者均接受经颅多普勒（transcranial doppler sonography， TCD）检查。记录大脑中动脉mBFV及双侧I/C mBFV。终点事件为DCI。计算I/C mBFV和大脑中动脉 mBFV≥120 cm/s预测DCI的敏感性、特异性、阳性预测值及阴性预测值。 结果 共44例患者纳入研究，共18例患者发生了迟发性脑缺血，发生率为41%。以大脑中动脉 mBFV≥120 cm/s为标准时，TCD诊断的敏感性是77.8%，特异性是50%，阳性预测值53.8%，阴性预测 值为75%。以I/C mBFV≥1.5为标准时，TCD的敏感性是71.8%，特异性是41.7%，阳性预测值50%，阴 性预测值为71.4%。 结论 对于高Fisher分级的蛛网膜下腔出血的患者，TCD仍是预测迟发性脑缺血的有利工具。与I/C mBFV≥1.5为标准相比，mBFV≥120 cm/s的预测价值更高。

关键词: 血流速度; 脑血管痉挛; 迟发性脑缺血; 蛛网膜下腔出血; 经颅多普勒