Comparison of wakefulness with two anaesthetic regimens. Total i.v. v. balanced anaesthesia.

Fifty-five patients were assigned randomly to receive either a total i.v. anaesthetic based on a two-stage infusion of etomidate plus increments of fentanyl or a regimen based on inhaled nitrous oxide with i.v. fentanyl increments. Using the isolated forearm technique, 44% of the nitrous oxide group were found to be wakeful at some time during surgery, whereas only 7% of the etomidate group were wakeful. There was one case of awareness in the nitrous oxide group.