[Electroencephalographic changes during ethrane anaesthesia in children (author's transl)].

Continuous electroencephalographic recordings were taken in 25 children who had ethrane-nitrous oxide anaesthesia without a basal anaesthetic. The recordings confirmed the repeatedly reported occurrence of certain abnormal wave patterns distinctive of seizures during ethrane anaesthesia. Although these dysrhythmias were more frequent and more pronounced at higher ethrane concentrations and during hyperventilation, sharp spikes began to appear already at concentrations of 1.0/p.c. without hyperventilation and at moderate depths of anaesthesia. In no case did the usual criteria for assessing depth of anaesthesia provide an indication of over-dosage. Although in the individual case there was a close relationship between the concentration of ethrane in the inhaled mixture and the electroencephalographic changes, the differences between the cases were too great to allow any prediction as to the concentration of ethrane that would bring on the dysrhythmia. Considering that increased cerebral oxygen consumption has been observed to accompany the abnormal wave patterns ethrane is not recommended for use in epileptic children or those with a familial history of epilepsy.