Abstracts

Rationale: Status epilepticus (SE) is defined as a continuous seizure or >2 seizures that last >5 or 30min. When SE does not respond to two intravenous medications, one of which is a benzodiazepine, it is termed refractory status epilepticus (RSE). In RSE, seizure duration is one of the only potentially modifiable factors for improving patient outcome. Studies have shown impact decreases rapidly as GABAa receptors involute and NMDA-glutamate receptors are expressed. These changes cause a significant reduction in efficacy of GABA-ergic drugs at a time in the status paradigm when morbidity and mortality increase.

Ketamine (KET) has a strong antagonistic effect on the NMDA receptor thereby blocking this stage of glutamatergic neurotoxicity and thus serves as an anti-inflammatory agent. Published studies have shown KETs rapid efficacy and safe use with a pooled seizure cessation rate of ~75%. Other benefits include rapid onset of action, neuroprotective effects, less volume & hemodynamic instability. Rare adverse effects are dissociative state/hallucinations the so-called “K-Hole”, a popularized recreational term, which may lend to scientific precaution in its use in epilepsy.

Methods: Our study began as a retrospective quality review of 4 RSE cases admitted to various intensive care units at Stony Brook University Hospital from 2018-2021, with prior poor control on multiple AEDs, and at least one sedative drip, but near 100% cessation rates after KET induction within 24 hours. This prompted a deep dive literature review, survey of our treating physicians, to develop a more standardized ketamine protocol and pharmacy-approved ICU power plan with primary epileptic endpoints. Using this protocol, we recorded EEG findings pre/post KET with goal of status abortion and average dosages and time to achieve this goal for a total of 11 patients.

Results: With the specific epileptic endpoints of status abortion, there was a near 100% rate of control after KET induction within 24hours. Most common etiology of RSE was cardiac arrest with nonconvulsive status epilepticus on initial EEG. At the time of commencement, all patients were on at least 3 AEDs and one sedative drip. KET average duration was 6 days. KET load averaged at 1.5 mg/kg, with start rates between 0.5- 1 mg/kg/hr and max rates 2-10mg/kg/h. In mostly all patients, ketamine may have provided the ability to wean off prior sedative drips within 5-6 days. The final Glasgow Outcome Scale (GOS) scale was 5-6 with poor outcomes but limited by initial insult injury and complicated hospital course of non-neurological etiologies.

Conclusions: As in many organic brain insults, the concept of “time is brain” is no different for status epilepticus. The focus is less on the agent, but more on what works for a rapid and relatively safe abortion of the status cycle to improve outcomes. Placing such a patient in a therapeutic ketamine reset i.e. the “K-Hole” appears to meet these requirements in our preliminary study of 11 patients. There is a critical need for robust standardized trials to advocate earlier widespread use, with the hope to offer yet, another “quick response warrior” in the fight against RSE.

Funding: Please list any funding that was received in support of this abstract.: No funding.