Parameters leading to cerebrospinal fluid diversion in low-grade subarachnoid hemorrhage – a Neurobase study

ABSTRACT Background and Purpose Patients admitted for subarachnoid hemorrhage (SAH) may require cerebrospinal fluid (CSF) diversion. The rate and indications for CSF diversion are highly variable. This study aimed to identify factors associated with CSF diversion in low-grade SAH in clinical practice. Methods We used a prospectively collected multicentric database (Neurobase®) cohort of patients with severe acute cerebral injuries, in three intensive care units (ICU) in France between March 2022 and June 2024. We included patients with aneurysmal or sine materia SAH with WFNS grades 1 to 3. Clinical and radiological variables were analyzed in patients with a CSF diversion during ICU stay. Hydrocephalus, cerebral hemorrhage and edema were quantified on admission CT-scans. Results Our cohort included 219 patients, mainly women (61%), on average 53 years old, mostly WFNS grade 1 (68%). Shunts were placed in 45% of patients, of which 92% were external ventricular drains, and 75% were placed in the first 24 hours. The predictors of CSF diversion in the first 24 hours in multivariate analysis were the delay between symptoms and first CT-scan (adjusted OR [aOR], 0.67 [95% CI, 0.45-0.99]), a GCS in the first 24 hours < 15 (aOR, 3.17 [95% CI, 1.42-7.10]), the ventricular Hijdra score (aOR, 1.48 [95% CI, 1.19-1.85]), temporal horn dilation (aOR, 1.89 [95% CI, 1.25-2.87]), and a Subarachnoid hemorrhage Early Brain Edema Score (SEBES) of 2 (aOR, 4.83 [95% CI, 1.57-14.87]). These predictors were also associated with CSF diversion at any time of ICU stay. We tested the centers and found a statistical significance (p < 0.001). Conclusion The decision to place a CSF shunt depends not only on hydrocephalus, altered mental status, and intraventricular hemorrhage, but also on cerebral edema and the delay between the first symptoms and CT-scan. The variability of practice in the included centers highlights a gray zone in the indication of CSF diversion.