Abstract WP214: Comparative Analysis of CSF Drainage from Lumbar and External Ventricular Drains in Aneurysmal Subarachnoid Hemorrhage

Introduction: Delayed cerebral ischemia is the most widely recognized mediator of secondary brain injury in aneurysmal subarachnoid hemorrhage (aSAH), primarily resulting from toxic, blood byproducts in the subarachnoid space. Recent trials have subsequently demonstrated that incorporating lumbar drains (LD) into standard clinical care may improve functional outcomes by accelerating the removal of these blood products from the leptomeningeal space. However, there remains a paucity of data on the differences in measured red blood cell (RBC) concentrations in cerebrospinal fluid (CSF) collected from both LDs and external ventricular drains (EVD) in real-world clinical practice to support this mechanism. Methods: We retrospectively evaluated the first five consecutive patients with aSAH who had both types of drains placed at a single, major academic institution. The CSF cell counts collected from LDs and EVDs at multiple time points were compared, assessing the concentration of RBCs. The time points were grouped by early window (