(760) Evaluation of Nimodipine Utilization in Patients With Aneurysmal Subarachnoid Hemorrhage

Introduction: Nimodipine is routinely utilized, and guideline recommended for the prevention of delayed cerebral ischemia (DCI) and improving functional outcomes in aneurysmal subarachnoid hemorrhage (aSAH). Hypotension is a common complication with its use and can often prevent patients from achieving the recommended total cumulative dose of 7,560 mg over 21 days. Previous studies have found nimodipine interruption to worsen neurologic outcomes, but the minimum effective dose remains unclear. The goal of this study was to evaluate the relationship between the cumulative nimodipine dose received and clinical outcomes in patients with aSAH and evidence of vasospasm.

Methods: We conducted a single center, retrospective, chart review of adult patients with aSAH who had evidence of vasospasm identified by transcranial doppler (TCD) and received nimodipine from January 2022 to December 2023. Patients were stratified and analyzed based on whether they fell below a target dose percentage (BTD%) or above a target dose percentage (ATD%) expected for a standard nimodipine course. Target dose thresholds were >90% during days 1-7, >75% during days 8-14, and >50% during days 15-21 post-bleed as well as a cumulative dose of >65% over the total 21-day course. Neurologic outcomes evaluated include incidence of DCI, days in vasospasm and need for digital subtraction angiography (DSA).

Results: During days 1-7, the BTD% group (n=16) when compared to the ATD% group (n=18) had a greater incidence of DCI (44% vs 17%; P = 0.13), total days in vasospasm (6.5 [3-7.5] vs 2.0 [2-7.5]; P = 0.1), and need for DSA (1.5 [0-4] vs 0 [0-1.8]; P = 0.056). The BTD% group was less often discharged to home (29% vs 75%; P = 0.015) and had lower Glascow Coma Scores at discharge (12 [8.8-15] vs 15 [14-15]; P = 0.065). Outcome differences between the BTD% group and ATD% group in the other time periods were less notable.

Conclusions: Apart from disposition, there were no statistically significant differences in outcomes between groups. There was a trend toward improved neurological outcomes in patients achieving a target nimodipine dose of >90% during days 1-7 post-bleed. Further investigation with a larger patient sample size is needed to validate the statistical significance of these findings.