(635) Hemodynamic Effects of Continuous-Infusion Midazolam in Refractory Status Epilepticus

Introduction: Although there is a paucity of evidence describing an optimal anesthetic therapy for refractory status epilepticus (RSE), the use of continuous infusion midazolam (cIV-MDZ) may be associated with less hemodynamic instability than other anesthetics. The primary objective of this evaluation was to determine the proportion of patients receiving cIV-MDZ for RSE that developed hemodynamic compromise (HDC). Secondary objectives included comparing cIV-MDZ treatment exposures and clinical outcomes in patients that developed HDC to those that did not.

Methods: This retrospective nested case-control study included patients receiving cIV-MDZ for RSE between August 1, 2019 and July 31, 2022 at a single tertiary academic medical center in the United States. Descriptive statistics and univariate analyses were used to compare treatment exposures and clinical outcomes in patients that developed HDC, defined as the initiation or escalation of vasopressor requirements, to those that did not.

Results: Of 112 patients included, 76 (67.9%) developed HDC and 36 (32.1%) did not. Patients that developed HDC received higher mean maximum doses of cIV-MDZ (0.88 mg/kg/hr [standard deviation (SD) ± 0.58] vs. 0.55 mg/kg/hr [SD ± 0.45], p< 0.001) and longer durations of cIV-MDZ (2.5 days [interquartile range (IQR) 1.6-3.6] vs. 1.5 days [IQR 0.7-2.1], p< 0.001). Patients that developed HDC also had longer intensive care unit lengths of stay (13.7 days [IQR 7.7-19.6] vs. 8.9 days [IQR 4.7-16.6], p=0.05) and hospital durations (21.2 days [IQR 14.8-30.5] vs. 13.3 days [IQR 8-23.5], p< 0.01). Seizure recurrence (34.2% HDC vs. 25% no HDC, p=0.33) and in-hospital mortality rates (23.7% HDC vs. 19.4% no HDC, p=0.62) did not differ significantly between patient groups.

Conclusions: The majority of patients receiving cIV-MDZ for RSE developed HDC. Patients that developed HDC received higher doses and longer durations of cIV-MDZ. These results may be used to guide further studies seeking optimal cIV-MDZ doses for efficacy while minimizing adverse effects.