Neurogenic Pulmonary Edema After Subarachnoid Hemorrhage: Risk Factors and Comorbidities

Introduction: Neurogenic Pulmonary Edema is a rare complication of subarachnoid hemorrhage that is associated with increased morbidity and poor clinical outcomes. There is a scarcity of literature describing the incidence and risk factors associated with this complication. The aim of this study was to identify patients who are at risk of developing neurogenic pulmonary edema in subarachnoid hemorrhage.

Methods: The 2016 to 2020 National Inpatient Sample (NIS) was used to identify adult inpatients with a primary diagnosis of non-traumatic subarachnoid hemorrhage. Univariate and multivariable analyses adjusting for patient demographics, comorbidity status, and hemorrhage etiology were used to characterize statistical associations with disease-related complications.

Results: A total of 149,465 patients were identified as having a subarachnoid hemorrhage from 2016 to 2020. Of these patients 4,690 patients (3.14%) were found to have neurogenic pulmonary edema. Neurogenic Pulmonary Edema was associated with increased length of stay (18.55±0.21 vs. 11.95±0.04, p< 0.001), increased total costs ($469,472.28±5732.44 vs. $264,024.35±806.40, p< 0.001), increased number of procedures (9.16±0.09 vs. 5.47±0.01, p< 0.001), increased number of days from admission to first procedure (2.02±0.07 vs. 1.53±0.01, p< 0.001), and increased mortality (22.7% vs. 18.6%, p< 0.001). After controlling for confounding factors, independent risk factors for neurogenic pulmonary edema in patients with subarachnoid hemorrhage included: subarachnoid hemorrhage from anterior communicating artery (Odds Ratio [OR]:1.32, 95% Confidence Interval [CI]:1.05-1.67, p< 0.019), subarachnoid hemorrhage from posterior communicating artery (OR:1.51, CI:1.19-1.91, p< 0.001), subarachnoid hemorrhage from vertebral artery (OR:1.51, CI:1.09-2.10, p=0.014), nonruptured cerebral aneurysm (OR:1.18, CI:1.07-1.29, p< 0.001), anemia (OR:1.57, CI:1.48-1.69, p< 0.001), coagulation deficiencies/disorders (OR:1.46, CI:1.32-1.61, p< 0.001), and obesity (OR:1.63, CI:1.51-1.77, p< 0.001).

Conclusion : Neurogenic Pulmonary Edema after subarachnoid hemorrhage is associated with an increased complicated hospital course. Neurosurgeons should be aware of the comorbidities and factors associated with increased neurogenic pulmonary edema after subarachnoid hemorrhage in order to improve patient outcomes.