Risk Factors Associated with Increased Cerebral Vasospasms After Subarachnoid Hemorrhage

Introduction: Cerebral vasospasms are a common complication of subarachnoid hemorrhages and remain the most serious and deadly complication in patients who survive the first 48 to 72 hours after a subarachnoid hemorrhage. The literature on risk factors and comorbidities associated with an increased risk of this complication is scarce and variable. The aim of this study was to identify patients who are at risk of developing cerebral vasospasms in subarachnoid hemorrhage and the effects it can have on inpatient hospital course.

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 28,865 patients (19.31%) were found to have cerebral vasospasms. Cerebral vasospasms were associated with increased length of stay (20.81±0.09 days vs. 10.08±0.04 days, p < .001), increased total costs ($493,084.27±2307.96 vs. $217,278.51±756.58, p < .001), increased number of procedures (9.7±0.04 vs. 4.6±0.01, p < .001), and increased number of days from admission to first procedure (1.86±0.03 days vs. 1.46±0.01 days, p < .001). After controlling for confounding factors, independent risk factors for cerebral vasospasms in patients with subarachnoid hemorrhage included: Hispanic ethnicity (Odds Ratio [OR]:1.05, 95% Confidence Interval [CI]:1.01-1.10, p=0.013), subarachnoid hemorrhage from anterior communicating artery (OR:1.40, CI:1.28-1.54, p < .001), non-ruptured cerebral aneurysm (OR:1.45, CI:1.38-1.51, p < .001), anemia (OR: 1.63, CI:1.58 -1.69, p < .001), obesity (OR:1.21, CI:1.16-1.26, p < .001), cocaine and nicotine use (OR:1.19, CI:1.15-1.23, p < .001), and hypertension (OR:1.15, CI: 1.11-1.19, p < .001).

Conclusion : Cerebral Vasospasms after subarachnoid hemorrhage are associated with an increased complicated hospital course. Neurosurgeons should be aware of the comorbidities and factors associated with increased cerebral vasospasm occurrence after subarachnoid hemorrhage in order to improve patient outcomes.