Predicting the Lack of Development of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE: Patients with aneurysmal subarachnoid hemorrhage are typically kept in the intensive care unit to be monitored for signs of delayed cerebral ischemia (DCI). Identifying patients at lower risk for DCI could have a positive financial impact by allowing earlier transfer from the intensive care unit. METHODS: We analyzed 307 consecutive patients admitted to the intensive care unit. Demographic, clinical, and neuroimaging data were recorded. The relationship with absent DCI was analyzed using univariate and multivariate logistic regression models. RESULTS: DCI did not develop in 169 patients (57.9%). Among factors at admission, age 68 years or older (P=0.0003; OR, 3.16; 95% CI, 1.66-6.39), World Federation of Neurological Surgeons (WFNS) I to III at presentation (P=0.0003; OR, 2.73; 95% CI, 1.57-4.79), WFNS I to III at worst (P=0.0003; OR, 2.39; 95% CI, 1.48-3.87), WFNS I to III after resuscitation (P=0.0006; OR, 2.85; 95% CI, 1.56-5.32), modified Fisher grade 1 to 2 (P=0.0021; OR, 2.43; 95% CI, 1.37-4.47), absence of intracranial hematoma (P=0.0042; OR, 2.26; 95% CI, 1.29-4.01), and aneurysm in the posterior circulation (P=0.025; OR, 1.74; 95% CI, 1.07-2.87) were associated with absence of DCI. On multivariate analysis, a model including age 68 years or older, WFNS I to III at presentation and a modified Fisher grade 1 to 2 were independently predictive of the absence of DCI, with a specificity of 100% and a positive predictive value of 100%. CONCLUSIONS: We propose a new model that can reliably identify patients with aneurysmal subarachnoid hemorrhage who are at very low risk for DCI. These patients could be candidates for early transfer to the general ward.