ATYPICAL TRIPHASIC WAVES ASSOCIATED WITH THE USE OF PENTOBARBITAL

To report a case in which triphasic waves developed during pentobarbit al treatment. Pentobarbital coma is indicated in status epilepticus, r efractory to other anticonvulsants, and in certain neurologic conditio ns in order to decrease brain metabolism. At high doses of pentobarbit al, the EEG shows a typical burst-suppression pattern, while at low do ses, diffuse slowing. Triphasic waves have not been reported in associ ation with pentobarbital. A 54-year-old female underwent surgery for g iant ophthalmic aneurysm clipping. Due to tearing and bleeding of the carotid artery, a clamp was placed, an external-internal carotid arter y bypass was done, and the patient was started on pentobarbital. The p atient remained comatose, the EEG showed a burst-suppression pattern, and the pentobarbital level was 30.5 mu g/dl. One week later, the pati ent was still comatose, the EEG showed generalized triphasic waves wit h anterior predominance, and the pentobarbital level was 11 mu g/dl. O ne day later, the patient was awake, and the EEG was normalized. The p atient made a complete recovery. Triphasic waves may be seen in patien ts on pentobarbital. It is important to recognize this finding in pati ents on pentobarbital due to status epilepticus. This pattern should n ot be misinterpreted as 'electrical' status epilepticus. (C) 1997 Else vier Science Ireland Ltd.