Incidence and Risk Factors of Vasospasm in Patients with Postoperative Delirium After Aneurysmal Subarachnoid Hemorrhage: A Propensity-adjusted Multivariate Analysis

Introduction: Postoperative care of aneurysmal subarachnoid hemorrhage (aSAH) patients often involves detecting and managing vasospasm, a contributor to delayed cerebral ischemia. Vasospasm presents with a variety of symptomatology, including confusion and impaired consciousness. Likewise, postoperative delirium is a frequent occurrence with ICU patients and incidentally shares similar neurocognitive symptoms as vasospasm. We sought to understand the incidence and risk factors of vasospasm in patients with postoperative delirium after aSAH.

Methods: A retrospective analysis at our high-volume stroke center was performed to include all ICU patients with aSAH who screened positive for delirium ≥ 2 days using the Confusion Assessment Method for the ICU (CAM-ICU). The primary outcome was vasospasm occurrence. Univariate analysis was performed using Welch’s two sample t-test for continuous variables, and chi-square test for categorical variables. Multivariate logistic regression was used to predict vasospasm, adjusted for aneurysmal characteristics, patient presentation including Richmond Agitation Sedation Scale (RASS), and operative decisions.

Results: 59 patients with aSAH who screened positive for postoperative delirium were included for analysis. The incidence of vasospasm was 81.4%. Patients with vasospasm were younger (SMD = 0.9611, p = 0.008) and endured operative sedation for 4 minutes longer (SMD = 0.861, p = 0.04). Multivariate predictors of vasospasm included RASS at admission (OR = 2.119 (95% CI: 1.061 - 16.19), p = 0.031) and diabetes (OR = 0.026 (95% CI: 0 - 0.924), p = 0.045). A one point increase in RASS at admission corresponded to a 2-fold increase in vasospasm risk.

Conclusion : ICU patients with aSAH postoperative delirium demonstrated a high incidence of vasospasm and reemphasized the association between longer sedation duration and vasospasm. The analysis introduced a potential relationship between a positive trend in RASS and vasospasm risk, necessitating additional research into the prognostic value of delirium screening tools in diagnosing vasospasm.