Reconsideration of Neurogenic Pulmonary Edema as Source of Metastatic Cerebral Abscess Following Subarachnoid Hemorrhages: A Preliminary Study

Prevalence, in-hospital mortality, and factors related to neurogenic pulmonary edema after spontaneous subarachnoid hemorrhage: a systematic review and meta-analysis

Neurogenic pulmonary edema (NPE) is a life-threatening and severe complication in patients with spontaneous subarachnoid hemorrhage (SAH). The prevalence of NPE varies significantly across studies due to differences in case definitions, study populations, and methodologies. Therefore, a precise estimation of the prevalence and risk factors related to NPE in patients with spontaneous SAH is important for clinical decision-makers, policy providers, and researchers. We conducted a systematic search of the PubMed/Medline, Embase, Web of Science, Scopus, and Cochrane Library databases from their inception to January 2023. Thirteen studies were included in the meta-analysis, with a total of 3,429 SAH patients. The pooled global prevalence of NPE was estimated to be 13%. Out of the eight studies (n = 1095, 56%) that reported the number of in-hospital mortalities of NPE among patients with SAH, the pooled proportion of in-hospital deaths was 47%. Risk factors associated with NPE after spontaneous SAH included female gender, WFNS class, APACHE II score ≥ 20, IL-6 > 40 pg/mL, Hunt and Hess grade ≥ 3, elevated troponin I, elevated white blood cell count, and electrocardiographic abnormalities. Multiple studies showed a strong positive correlation between the WFNS class and NPE. In conclusion, NPE has a moderate prevalence but a high in-hospital mortality rate in patients with SAH. We identified multiple risk factors that can help identify high-risk groups of NPE in individuals with SAH. Early prediction of the onset of NPE is crucial for timely prevention and early intervention.

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 WFNS 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.