Acute pulmonary edema after subarachnoid hemorrhage: risk factors and comorbidities—an analysis of a nationwide database from the United States

BACKGROUND: Acute pulmonary edema (APE) is a rare complication of subarachnoid hemorrhage (SAH) that is associated with increased morbidity and poor clinical outcomes. There is limited literature addressing the incidence and risk factors of this complication, highlighting the need for further investigation as undertaken in the present study. METHODS: The 2016 to 2021 National Inpatient Sample (NIS) was used to identify adult inpatients with a primary diagnosis of non-traumatic SAH. Univariate and multivariable analyses adjusting for patient demographics, and comorbidity status, were used to characterize statistical associations with APE. RESULTS: A total of 42,141 patients were identified as having SAH from 2016 to 2021. Of these patients, 960 patients (2.3%) were found to have APE. APE was associated with increased length of stay (20.0 ± 18.9 days vs. 11.6 ± 14.3, p < 0.001), increased total costs ($503,671.3 ± 647,729.9 vs. $238,724.6 ± 328,062.1, p < 0.001), increased number of days from admission to first procedure (3.5 ± 7.3 vs. 1.9 ± 4.9, p < 0.001), increased Elixhauser comorbidity index ≥ 3 (77.5% vs. 66.0%, p < 0.001), and increased mortality (40.2% vs. 22.5%, p < 0.001). After controlling for confounding factors, independent risk factors for APE in patients with non-traumatic SAH included: Coagulopathies (adjusted Odds Ratio [aOR]: 1.57, 95% confidence interval [CI] 1.31-1.89, p < 0.001), Fluid and Electrolyte Disorders (aOR: 2.54, CI 2.13-3.03, p < 0.001), Liver Disease (aOR: 1.37, CI 1.07-1.76, p = 0.013), Obesity (aOR: 1.47, CI 1.19-1.81, p = 0.003), Pulmonary Circulatory Disorder (aOR: 1.72, CI 1.31-2.26, p = 0.001), and Weight Loss (aOR: 1.67, CI 1.36-2.04, p < 0.001). CONCLUSION: APE after SAH is associated with increased complicated hospital course. Neurosurgeons and Neurocritical care medical professionals should be aware of the comorbidities and factors associated with increased APE after SAH to improve patient outcomes.