Abstracts

Pentobarbital is a widely used for the treatment of refractory status epilepticus. The EEG is usually continuously monitored during pentobarbital administration and during the withdrawal period and is the basis for the decision to resume pentobarbital or continue its withdrawal. We observed a pattern of periodic sharp EEG discharges related to pentobarbital withdrawal. This pattern is transient with continued withdrawal. It is not associated with clinical seizure activity and is not predictive of recurrence of status epilepticus. This pattern is important to describe and recognize because it may result in unnecessary resumption of pentobarbital., We recognized a periodic pattern during recovery from pentobarbital coma in 5 patients. EEG was recorded intermittently in all, for 20-30 minutes every 8 hours in the first patient, using paper EEG, and for 5 minutes every 30 minutes for the remaining patients (using digital EEG recording). We reviewed the EEG pattern during pentobarbital withdrawal. We also reviewed the clinical history, including outcome in all patients., The first patient received pentobarbital for increased intracranial pressure after traumatic brain injury and the other four received pentobarbital for refractory status epilepticus. During pentobarbital withdrawal all developed a pattern of sharply contoured periodic complexes, typically with a recurrence rate of one every 1-2 seconds. In the first patient, this was interpreted as electrographic status epilepticus. However, after several repeated trials of pentobarbital, it was realized that this may not be a seizure pattern and pentobarbital was fully withdrawn with no clinical seizure activity. With the remaining patients, the pattern was recognized earlier, thus avoiding prolonged pentobarbital treatment. In all patients, the periodic pattern evolved into more continuous EEG activity that was not ictal. This was associated with clinical recovery, though not necessarily to pre-status baseline., A periodic EEG pattern may occur in association with pentobarbital withdrawal. When such a pattern is not associated with clinical seizure activity, it should not be a reason to resume pentobarbital since it is usually not an ictal pattern.[figure1],