Screening Computed Tomography Angiography to Identify Patients at Low Risk for Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

Sex-Related Differences in Mortality, Delayed Cerebral Ischemia, and Functional Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

Background/Objective: Sex-related differences among patients with aneurysmal subarachnoid hemorrhage (aSAH) and their potential clinical implications have been insufficiently investigated. To address this knowledge gap, we conduct a comprehensive systematic review and meta-analysis. Methods: Sex-specific differences in patients with aSAH, including mortality, delayed cerebral ischemia (DCI), and functional outcomes were assessed. The functional outcome was dichotomized into favorable or unfavorable based on the modified Rankin Scale (mRS), Glasgow Outcome Scale (GOS), and Glasgow Outcome Scale Extended (GOSE). Results: Overall, 2823 studies were identified in EMBASE, MEDLINE, PubMed, and by manual search on 14 February 2024. After an initial assessment, 74 studies were included in the meta-analysis. In the analysis of mortality, including 18,534 aSAH patients, no statistically significant differences could be detected (risk ratio (RR) 0.99; 95% CI, 0.90-1.09; p = 0.91). In contrast, the risk analysis for DCI, including 23,864 aSAH patients, showed an 11% relative risk reduction in DCI in males versus females (RR, 0.89; 95% CI, 0.81-0.97; p = 0.01). The functional outcome analysis (favorable vs. unfavorable), including 7739 aSAH patients, showed a tendency towards better functional outcomes in men than women; however, this did not reach statistical significance (RR, 1.02; 95% CI, 0.98-1.07; p = 0.34). Conclusions: In conclusion, the available data suggest that sex/gender may play a significant role in the risk of DCI in patients with aSAH, emphasizing the need for sex-specific management strategies.

Transcranial Ultrasound in the Neurocritical Care Unit

Ultrasound evaluation of the brain is performed through acoustic windows. Transcranial Doppler has long been used to monitor patients with subarachnoid hemorrhage for cerebral vasospasm. Transcranial color-coded sonography permits parenchymal B-mode imaging and duplex evaluation. Transcranial ultrasound may also be used to assess the risk of delayed cerebral ischemia, screen patients for the presence of elevated intracranial pressure, confirm the diagnosis of brain death, measure midline shift, and detect ventriculomegaly. Transcranial ultrasound should be integrated with other point-of-care ultrasound techniques as an essential skill for the neurointensivist.

Vasospasm Surveillance by a Simplified Transcranial Doppler Protocol in Traumatic Brain Injury

OBJECTIVE

To detect post-traumatic vasospasm in patients with traumatic brain injury (TBI), we implemented a simplified transcranial Doppler (TCD) surveillance protocol in a neurointensive care setting. In this study, we evaluate the yield of this protocol.

METHODS

Adult patients with TBI admitted to the neurointensive care unit were examined with TCD by 2 intensive care nurses trained in TCD examinations. Flow velocities of the middle cerebral arteries were recorded. TCD suspected vasospasm was defined as the mean flow velocity >120 cm/s, and when detected, the protocol recommended a supplementary computed tomography angiography. The rate of detection of TCD suspected vasospasm and the subsequent rate of radiological diagnosis of vasospasm were recorded. In multivariate logistic regression analysis, we evaluated age, initial Glasgow Coma Scale, craniotomy, and decompressive craniectomy as potential predictors of developing increased TCD velocity.

RESULTS

A total of 84 patients with TBI with a median initial Glasgow Coma Scale score of 6 were examined by TCD. TCD suspected vasospasm was found in the middle cerebral arteries of 18% of examined patients. Two-thirds of patients with TCD suspected vasospasm were investigated with a subsequent computed tomography angiography, and 80% of these patients received a radiological diagnosis of vasospasm. In logistic regression analysis, decompressive craniectomy was significantly associated with increased risk of developing TCD suspected vasospasm (odds ratio: 11.57, 95% confidence interval: 2.59-51.73, P = 0.001).

CONCLUSIONS

The implementation of a simplified TCD surveillance protocol in a neurointensive care setting yielded an 18% detection rate of TCD suspected vasospasm. In our cohort of patients with TBI, decompressive craniectomy was associated with increased risk of developing TCD suspected vasospasm.