(590) Vasopressor Requirements in Patients Receiving IV Milrinone for Cerebral Vasospasm After aSAH

Introduction: The efficacy of milrinone for treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH) has been recently evaluated and was associated with a positive impact on long-term neurological and radiological outcomes. Hypotension is a recognized side effect after administering milrinone intravenously and vasopressors may be required to maintain optimal mean arterial pressure (MAP). However, there is a paucity of data on the vasopressor requirements and its effects in patients with aSAH after starting milrinone. The purpose of this study was to assess the vasopressor requirements of patients receiving intravenous milrinone and the adverse drug events associated with the addition of milrinone.

Methods: This was a single-center retrospective cohort study designed to evaluate the vasopressor requirements in patients receiving IV milrinone for cerebral vasospasm after aSAH. Patients 18 years and older admitted with a diagnosis of aSAH between January 2020 to January 2023, who received intravenous milrinone were included in the study. Patients were excluded if they had a CrCl < 20 ml/min or a diagnosis of end-stage renal disease, if they were incarcerated, and if they were pregnant at the time of enrollment. The primary objective was to characterize vasopressor requirements in patients receiving milrinone. Secondary objectives included assessing the incidence of adverse events including arrhythmias, hypokalemia, hyponatremia, and polyuria.

Results: The cohort included 21 patients who were treated with milrinone for cerebral vasospasm following aSAH. The median duration of milrinone treatment was 7 days. Of the 21 patients, 10 patients (47.6%) required vasopressors to maintain optimal mean arterial pressure, 6 of which were initiated on vasopressors after the initiation of milrinone. The most commonly initiated vasopressors were norepinephrine and phenylephrine with a median duration of 5.5 days.

Conclusions: Vasopressor use in patients receiving milrinone for the treatment of cerebral vasospasm following aSAH is common. There may be a direct correlation between milrinone dose and vasopressor requirements.