Canadian Journal of Anesthesia, Vol 9, 312-318, Copyright © 1962 by Canadian Anesthesiologists' Society

The Clinical Use of Imbretil

¹ Department of Anesthesiology, Hartford Hospital, Hartford, Connecticut, U.S.A.; Present address is Department of Anaesthesia, St. Joseph's Hospital, Hamilton, Ontario
² Department of Anesthesiology, Hartford Hospital, Hartford, Connecticut, U.S.A.

The long-lasting muscle-relaxant hexamethylene-l, 6-bis-carbaminoylcholine bromide (Imbretil) has been employed as the chief muscle-relaxant drug in 225 patients, most of whom were healthy, middle-aged females undergoing uncomplicated, major pelvic surgery. General anaesthesia usually was maintained with cyclopropane, and the dosage of Imbretil employed was 0.050 mg./kg.

The duration of apnoea following the administrtation of Imbretil averaged 56 minutes and 48 seconds, and the duration of clinically adequate muscular relaxation averaged 85 minutes and 18 seconds. When Imbretil was employed as the initial muscle-relaxant drug it produced very satisfactory conditions for endotracheal intubation. The most useful clinical technique, however, since it spared the duration of Imbretil activity for relaxation during actual operation, was the administration of a single dose of succinylcholine first to facilitate endotracheal intubation, then a single dose of Imbretil for abdominal relaxation, and then further small doses of succinylcholine as necessary if the effects of the Imbretil waned prior to the completion of the operative procedure.

Since Imbretil is a cumulative drug, repeated administrations should be avoided. However, a single dose of Imbretil, supplemented as necessary with small doses of succinylcholine, will produce adequate—even superb—relaxation during controlled respirations for lower abdominal surgery of up to l–2 hours' duration.