Clinical Features of Neurogenic Pulmonary Edema in Patients with Subarachnoid Hemorrhage

OBJECTIVE: Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by acute onset after central nervous system injury. Here, we investigated the clinical features of NPE in patients with subarachnoid hemorrhage (SAH). METHODS: We retrospectively analyzed a total of 350 patients with SAH who were treated at our hospital from April 2014 to September 2017. Patient demographics, aneurysm size and location, clinical characteristics, and patient outcomes were reviewed and compared between an NPE and a non-NPE group. RESULTS: Sixteen patients (4.6%) presented with NPE at admission. Ten of these (62.5%) recovered from NPE immediately, and ventilatory support was withdrawn within 2 days from onset. A univariate analysis showed that patients with NPE were younger (P = 0.04), had a higher rate of vertebral artery dissection (P < 0.01), more severe World Federation of Neurosurgical Societies (WFNS) grades (P = 0.01), and lower systolic blood pressure on admission (P = 0.01). A multivariate analysis revealed significant differences in the frequency of vertebral artery dissection (odds ratio 4.83, 95% confidence interval 1.50-15.56, P < 0.01) and in WFNS grades (odds ratio 3.73, 95% confidence interval 1.02-13.66, P = 0.04) between the groups. No significant group differences were found in other factors including heart rate, radiographic sign (Fisher grade), aneurysm size and location, blood sample tests on admission, and neurologic outcomes. CONCLUSIONS: Vertebral artery dissection and severe WENS grade on admission were confirmed as significant risk factors for NPE. However, neurologic outcomes at discharge did not differ between groups, suggesting that poor outcomes due to NPE could be reduced by appropriate diagnosis and treatment.