(762) Prolonged Pentobarbital Infusion in Super-Refractory Status Epilepticus

Introduction: Super-refractory status epilepticus (SRSE) is status epilepticus that continues or recurs 24 h or more after the onset of anesthetic therapy or recurs after reduction of such therapy. From published findings, it is estimated that ~15% of all status epilepticus will become SRSE. Pentobarbital (PTB) infusion to achieve EEG burst suppression is an effective measure but requires intubation due to potent general anesthesia and prolonged half-life.
We describe the incidence and outcomes of patients treated for SRSE with PTB infusion in a tertiary care Neurocritical Care Unit.

Methods: SRSE patients admitted from Jan 2018 to Mar 2021 were retrospectively analyzed. SRSE due to cardiac arrest related acute anoxic brain injury (ABI-SRSE) were separated. An escalating tier-based protocol was used that included 1) multi-receptor targeted antiepileptic drugs (AEDs); 2) anesthetic/ sedation infusions (midazolam, pentobarbital, propofol); 3) non-pharmacologic therapy (ketogenic diet, hypothermia, electroconvulsive therapy). Descriptive statistics were used.

Results: 16 patients were identified with SRSE. 5 patients had ABI-SRSE. The anoxia group mortality was 40% while in SRSE without anoxia, 64% (7/11) survived to discharge. Average length of stay was 24 days in ABI-SRSE vs 44 days (range 19—144). In SRSE without anoxia, 18% had autoimmune encephalitis, 18% spontaneous ICH, 10% had CVA and 45% had primary epilepsy plus exacerbating factor (infection or non-compliance). Average duration of mechanical ventilation was 29 days (range 8—75) in this group. In the same cohort, all patients (100%) received PTB infusion (range 3—16 days) and 91% were on a regimen of >4 AEDs. 54% were on a ketogenic diet, 37% received ECT, 18% were placed on induced hypothermia. 37% received high dose steroids.

Conclusions: PTB in the ABI-SRSE cohort ablated seizures but did not alter the dismal prognosis. However, in SRSE without ABI, a significant survival rate to discharge was seen despite prolonged ventilator and hospital length of stay attributable to PTB use. In this cohort, a multimodal protocol including aggressive pharmacological (including PTB infusion) and non-pharmacological therapies is essential to ablate SRSE as our study demonstrates a higher survival rate to discharge than previously described.