Department of Neurosurgery, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
Department of Diagnostic and Interventional Radiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
Neurocrit Care. 2023 Aug;39(1):125-134. doi: 10.1007/s12028-023-01683-8. Epub 2023 Feb 17.
Early computed tomography perfusion (CTP) is frequently used to predict delayed cerebral ischemia following aneurysmatic subarachnoid hemorrhage (aSAH). However, the influence of blood pressure on CTP is currently controversial (HIMALAIA trial), which differs from our clinical observations. Therefore, we aimed to investigate the influence of blood pressure on early CTP imaging in patients with aSAH.
We retrospectively analyzed the mean transit time (MTT) of early CTP imaging within 24 h after bleeding prior to aneurysm occlusion with respect to blood pressure shortly before or after the examination in 134 patients. We correlated the cerebral blood flow with the cerebral perfusion pressure in the case of patients with intracranial pressure measurement. We performed a subgroup analysis of good-grade (World Federation of Neurosurgical Societies [WFNS] I-III), poor-grade (WFNS IV-V), and solely WFNS grade V aSAH patients.
Mean arterial pressure (MAP) significantly correlated inversely with the mean MTT in early CTP imaging (R = - 0.18, 95% confidence interval [CI] - 0.34 to - 0.01, p = 0.042). Lower mean blood pressure was significantly associated with a higher mean MTT. Subgroup analysis revealed an increasing inverse correlation when comparing WFNS I-III (R = - 0.08, 95% CI - 0.31 to 0.16, p = 0.53) patients with WFNS IV-V (R = - 0.2, 95% CI - 0.42 to 0.05, p = 0.12) patients, without reaching statistical significance. However, if only patients with WFNS V are considered, a significant and even stronger correlation between MAP and MTT (R = - 0.4, 95% CI - 0.65 to 0.07, p = 0.02) is observed. In patients with intracranial pressure monitoring, a stronger dependency of cerebral blood flow on cerebral perfusion pressure is observed for poor-grade patients compared with good-grade patients.
The inverse correlation between MAP and MTT in early CTP imaging, increasing with the severity of aSAH, suggests an increasing disturbance of cerebral autoregulation with the severity of early brain injury. Our results emphasize the importance of maintaining physiological blood pressure values in the early phase of aSAH and preventing hypotension, especially in patients with poor-grade aSAH.
早期计算机断层灌注（CTP）常用于预测颅内动脉瘤性蛛网膜下腔出血（aSAH）后的迟发性脑缺血。然而，目前关于血压对 CTP 的影响存在争议（HIMALAIA 试验），这与我们的临床观察结果不同。因此，我们旨在研究血压对 aSAH 患者早期 CTP 成像的影响。
我们回顾性分析了 134 例患者在血管内夹闭动脉瘤前 24 小时内的早期 CTP 成像平均通过时间（MTT）与检查前后短时间内血压的关系。对于有颅内压监测的患者，我们将脑血流量与脑灌注压相关联。我们对 WFNS 分级 I-III（良好）、IV-V（不良）和单纯 WFNS V（不良）的患者进行了亚组分析。
平均动脉压（MAP）与早期 CTP 成像的平均 MTT 呈显著负相关（R=−0.18，95%置信区间[CI]−0.34 至−0.01，p=0.042）。较低的平均血压与较高的平均 MTT 显著相关。亚组分析显示，WFNS I-III（R=−0.08，95%CI−0.31 至 0.16，p=0.53）患者与 WFNS IV-V（R=−0.2，95%CI−0.42 至 0.05，p=0.12）患者之间的相关性呈递增趋势，但无统计学意义。然而，如果仅考虑 WFNS V 患者，则 MAP 与 MTT 之间存在显著且甚至更强的相关性（R=−0.4，95%CI−0.65 至 0.07，p=0.02）。在有颅内压监测的患者中，与良好级别的患者相比，不良级别的患者的脑血流对脑灌注压的依赖性更强。
早期 CTP 成像中 MAP 与 MTT 呈负相关，且随着 aSAH 严重程度的增加而增加，这表明随着早期脑损伤的严重程度增加，脑自动调节的紊乱程度增加。我们的结果强调了在 aSAH 早期阶段保持生理血压值和预防低血压的重要性，特别是在不良级别的 aSAH 患者中。
