Depth of EEG suppression and outcome in barbiturate anesthetic treatment for refractory status epilepticus

Purpose: Barbiturate anesthetic treatment of patients with refractory status epilepticus (RSE) is often titrated to a burst-suppression record an the EEG. We sought to determine whether the depth of EEG suppression correlated with persistent seizure control in such patients. Methods: We reviewed the EEGs and clinical course of patients treated with pentobarbital (PTB) for RSE. Persistent seizure control or relapse to status epilepticus after the taper of PTB was determined with reference to the depth of EEG suppression during treatment. Results: Of 35 patients tapering PTB, persistent seizure control was achieved in six of 12 patients reaching a burst-suppression record at greatest depth of EEG suppression and in 17 of 20 patients reaching a "flat" record; three patients with neither pattern had persistent control. Survival also was somewhat better in the more suppressed group. Isolated epileptiform discharges during the barbiturate infusion did not correlate with outcome. Recurrence of electrographic status after PTB taper predicted clinical relapse. Conclusions: The EEG is important in managing PTB treatment for patients with RSE. Some period of intense seizure and EEG suppression may help in preventing relapse of status after the PTB taper. It is not necessary to suppress all epileptiform discharges, but persistent clinical and EEG monitoring is necessary to avoid relapses.