Background

Management of external ventricular drainage (EVD) among aneurysmal subarachnoid hemorrhage (aSAH) patients remain controversial, and there are no consensus guidelines reporting optimal values of intracranial pressure (ICP).

Objective

To analyze predictors of delayed cerebral ischemia (DCI) after aSAH and the influence of ICP values on DCI.

Methods

We prospectively collected patients with aSAH requiring EVD. Predictors of DCI (new CT hypodensities developed within the first 3 weeks not related to others causes) were studied. Vasospasm and brain hypoperfusion were studied with CTA and CTP (RAPID software).

Results

Among 50 aSAH patients treated with EVD, 21 (42%) developed DCI, while 27 (54%) presented vasospasm. Mean ICP ranged between 2 mmHg and 19 mmHg. On the multivariate analysis, mean ICP (OR = 2, 95% CI = 1.01–3.9, P = 0.04) and mean volume of the hypoperfusion on Tmax delay > 6 (OR = 1.2, 95% CI = 1.01–1.3, P = 0.02) were the only independent predictors of DCI. To predict DCI, Tmax delay > 6 seconds presented the highest AUC (0.956), with a cutoff value of 18 mL showing sensitivity, specificity, PPV, NPV, and accuracy of 90.5% (95% CI = 69%–98.8%), 86.2% (95% CI = 68.4%–96%), 82.6% (95% CI = 65.4%–92%), 92.5% (95% CI = 77%–98%), 88% (95% CI = 75%–95%), respectively. The AUC of the mean ICP was 0.825, and the best cutoff value was 6.7 mmHg providing sensitivity, specificity, PPV, NPV, and accuracy of 71.4% (95% CI = 48%–89%), 62% (95% CI = 42%–79%), 58% (95% CI = 44%–70%), 75% (95% CI = 59%–86%), 66% (95% CI = 51%–79%) for the prediction of DCI, respectively.

Conclusion

ICP < 7 mmHg could potentially be beneficial in decreasing DCI. Whole-brain CTP allows a reliable DCI prediction, and a hypoperfusion volume larger than 18 mL at Tmax delay > 6 seconds can predict more than 80% of DCI (Fig. 1, Fig. 2).

中文翻译：

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动脉瘤性蛛网膜下腔出血患者的目标颅内压：一项前瞻性单中心研究

背景

动脉瘤性蛛网膜下腔出血（aSAH）患者的外部心室引流（EVD）处理仍存在争议，目前尚无共识性指南报道颅内压（ICP）的最佳值。

目的

分析aSAH后延迟性脑缺血（DCI）的预测因子以及ICP值对DCI的影响。

方法

我们前瞻性收集了需要EVD的aSAH患者。研究了DCI的预测因子（在最初的3周内出现了新的CT低密度，与其他原因无关）。使用CTA和CTP（RAPID软件）研究了血管痉挛和脑灌注不足。

结果

在接受EVD治疗的50名aSAH患者中，有21名（42％）发生DCI，而27名（54％）出现血管痉挛。ICP的平均范围为2 mmHg至19 mmHg。在多变量分析中，平均ICP（OR = 2，95％CI = 1.01-3.9，P  = 0.04）和在Tmax延迟> 6时的平均灌注量（OR = 1.2，95％CI = 1.01-1.3，P = 0.02）是DCI的唯一独立预测因子。为了预测DCI，Tmax延迟> 6秒表示最高的AUC（0.956），截断值为18 mL，显示出灵敏度，特异性，PPV，NPV和90.5％的准确性（95％CI = 69％–98.8％）， 86.2％（95％CI = 68.4％–96％），82.6％（95％CI = 65.4％–92％），92.5％（95％CI = 77％–98％），88％（95％CI = 75 ％–95％）。平均ICP的AUC为0.825，最佳截止值为6.7 mmHg，灵敏度，特异性，PPV，NPV和准确度分别为71.4％（95％CI = 48％–89％），62％（95％CI = 42％–79％），58％（95％CI = 44％–70％），75％（95％CI = 59％–86％），66％（95％CI = 51％–79％） DCI的预测。

结论

ICP <7 mmHg可能有助于降低DCI。全脑CTP允许可靠的DCI预测，而在Tmax延迟> 6秒时大于18 mL的低灌注量可以预测80％以上的DCI（图1，图2）。