Canadian Journal of Anesthesia, Vol 15, 357-361, Copyright © 1968 by Canadian Anesthesiologists' Society

Electroencephalographic Monitoring in Anaesthesia with Droperidol and Fentanyl

¹ Department of Anaesthesia, University of Toronto, and Toronto General Hospital

The technique of neuroleptanalgesia offers the specific advantages of freedom from marked cardiovascular side-effects and ease of reversibility. Because of these advantages, the technique was adapted for use with very light general anaesthesia in neurosurgical procedures. EEG recording was carried out in an attempt to establish a means of accurately monitoring the depth of anaesthesia. The EEG pattern obtained from patients receiving neuroleptanalgesia showed specific changes compared to the record taken from the same patients prior to the administration of the neuroleptic drugs. Light surgical anaesthesia with nitrous oxide and oxygen added to droperidol and fentanyl showed very little change from the pattern with neuroleptanalgesia alone. The further addition of halothane or thiopentone produced a marked change in the EEG pattern.

With the technique used, once an adequate level of anaesthesia had been achieved, with or without supplementary anaesthesia, it was quite feasible to maintain this level with the use of the electroencephalographic monitoring.