(616) Cisternal Hemorrhagic Volume and GCS Predict Need for Chronic Ventilation in Subarachnoid Hemorrhage

Introduction: Aneurysmal subarachnoid hemorrhage (aSAH) is a type of hemorrhagic stroke with thirty-day mortality as high as 40%. Even patients who survive have myriad of long-term complications. We have developed and previously reported on a simplified quantifiable method to conduct a volumetric analysis of aSAH and demonstrated its correlation with outcome and mortality. We conducted this study to identify correlation between aneurysmal subarachnoid hemorrhage (aSAH) volume, and other clinical covariates at the time of presentation with need for chronic mechanical ventilation.

Methods: We analyzed 277 patients with aSAH admitted at our Comprehensive Stroke Center (CSC) at Mayo Clinic Florida between 2012 and 2022. We have derived a mathematical model (Model 1) to measure aSAH basal cisterns blood volume using a derivation of the ABC/2 ellipsoid formula, where A = width/thickness, B = length, C = vertical extension) on non-contrast CT which is comparable to manual segmentation (Model 2) on non-contrast CT (NCCT) scans. We used this volumetric data with other clinical covariates including gender, age, intraventricular hemorrhagic volume, intraparenchymal hemorrhagic volume, modified Fisher’s Score (mFS), Hunt and Hess score and GCS in a multivariate model to establish correlation with need of chronic mechanical ventilation (defined by tracheostomy placement during admission). Multivariate logistic regression analysis with stepwise elimination of variables not contributing to the model (0.05 significance level for entry into the model) was used for entry into the model, followed by receiver operator characteristics (ROC) curve, and area under curve analysis.

Results: We found that GCS score, mFS, Hunt and Hess score, and SAH volume were independently associated with the need of chronic mechanical ventilation in our cohort. However, on conducting stepwise elimination multivariate regression analysis only GCS and SAH volume were significantly correlated with need for chronic mechanical ventilation with AUC (0.81).

Conclusions: Our simplified volumetric analysis model is useful in predicting the need for chronic mechanical ventilation in patients with aSAH.