Canadian Journal of Anesthesia, Vol 11, 168-172, Copyright © 1964 by Canadian Anesthesiologists' Society

Electrical Anaesthesia the use of a Combination of Alternating and Direct Electrical Current in Dogs

¹ Department of Pharmacology and Anaesthesia University of Alberta Edmonton, Alberta

Observations on the use of an apparatus producing an alternating square wave superimposed on a direct electric current are made. Thiopentone 15 mg /kg was administered intravenously to dogs and the animals were intubated. When definite muscular, respiratory, and cardiovascular response to painful stimuli had returned, electric current was applied through palladium electrodes on the vertex and the roof of the mouth After preliminary experiments the technique adopted was the immediate application of 20 ma d-c and introduction of 200 c p s 2 msec wave width a-c during the ensuing two minutes until a final current of 9 ma peaking to 40 ma was reached. The wave width and firecjueny were then reduced simultaneously and the current increased to maintain current flow Wave widths of 15 msec at 100 c p s was sometimes adequate or there was further reduction to 1 0 msec 100 c p s. Current flow varied between 12 tnd 13 ma peaking at 60-90 ma These secondary current changes took about three minutes. Anaesthesia was maintained for 1-1 hours. Significant changes in blood pressure did not occur Satisfactory respiratory exchange was maintained during induction but maximal analgesia tended to be associated with deep stertoious respiration Glomerular filtration rate was not significantly diminished Rectal temperature increased 1-3 degrees Centigrade and oxygen consumption increased 20-100 per cent above that of the dog under the influence of thiopentone

The conclusion reached was that, although the tedbnique developed was unsuccessful in the production of optimum conditions for surgery, it was much superior to a 700 c p s sine wave current, and it was though that a satisfactory technique of elactncal anaesthesia would ultimately be developed