Introduction: Delayed cerebral ischemia (DCI) is a recognized complication of aneurysmal subarachnoid hemorrhage (aSAH) that contributes to poor outcome. This study seeks to determine the effect of nosocomial infection on the incidence of DCI and patient outcome.

Methods: An exploratory analysis was performed on 156 aSAH patients enrolled in the Cerebral Aneurysm Renin Angiotensin System (CARAS) study. Clinical and radiographic data were analyzed with univariate analysis to detect risk factors for the development of DCI and poor outcome. Multivariate logistic regression was performed to identify independent predictors of DCI.

Results: One hundred and fifty three patients with aSAH were included. Delayed cerebral ischemia was identified in 32 (20.9%) patients. Nosocomial infection, ventriculitis, aneurysm rerupture, and clinical vasospasm were independently associated with the development of DCI [3.5 (1.93 – 6.35), p < 0.00; 25.3 (4.39 – 110.9), p = 0.03; 7.55 (2.72 – 20.9), p = 0.05; 43.4 (23.6 - 79.8), p < 0.00; respectively]. Diagnosis of nosocomial infection preceded the diagnosis of DCI in 15 of 21 (71.4%) patients. Patients diagnosed with nosocomial infection experienced significantly worse outcomes as measured by mRS at discharge and 1 year (p < 0.00 and p = 0.03, respectively).

Conclusions: Nosocomial infection is independently associated with DCI. This association is hypothesized to be partly causative through the exacerbation of systemic inflammation leading to thrombosis and subsequent ischemia.

Patient Care: This research explores clinical risk factors associated with delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage. Nosocomial infection was identified as an independent risk factor for DCI. This finding indicates that systemic inflammation plays a role in the pathophysiology of DCI in aSAH patients. Additionally, it identifies a potentially modifiable risk factor for DCI in these patients.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) identify clinical risk factors for DCI, 2) understand that nosocomial infection is associated with DCI, 3) contemplate possible pathophysiologic mechanisms to explain the association between infection and DCI.

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