Canadian Journal of Anesthesia, Vol 2, 362-365, Copyright © 1955 by Canadian Anesthesiologists' Society

The Combined Use of Nisentil® Hydrochloride and Levallorphan Tartrate for the Supplementation of Nitrous Oxide–Oxygen Anaesthesia

¹ Department of Anesthesia, Mercy Hospital, and the Section of Anesthesiology, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pa., U.S.A.
² Department of Anaesthesia, Salford Royal Hospital, Manchester, England
³ Department of Clinical Research, Hoffmann-La Roche Inc., Nutley, N.J., U.S.A.

A technique is described which utilizes the combined administration of Nisentil Hydrochloride and levallorphan tartrate, in a 50: L ratio, for supplementation of N₂O–O₂–Pentothal Sodium anaesthesia. The possibility of employing large doses of Nisentil, without producing respiratory depression, was demonstrated in 452 patients. In 32 per cent of the patients, who did not require endotracheal intubation, the use of Pentothal could be eliminated. In the remaining 68 per cent, who did not require intubation, and in the patients who required muscular relaxation, the Pentothal requirements were reduced by approximately 50 per cent, as compared with patients who received Nisentil without levallorphan. Over 90 per cent of all patients reacted to stimulation within 5 minutes after discontinuation of N₂O–O₂ and 50 per cent did not require analgesics during the first eight postoperative hours.