Canadian Journal of Anesthesia, Vol 17, 485-494, Copyright © 1970 by Canadian Anesthesiologists' Society

The Metabolic Response to Pentazocine as a Supplement to Balanced Anaesthesia for Major Abdominal Surgery

¹ Department of Anesthesiology, State University Hospital, State University of New York, Upstate Medical Center, Syracuse, New York

Pentazocine was employed as a supplement to nitrous oxide and succinylcholine for major abdominal surgery in two similar groups of adult patients who differed only in that one group received thiopental for induction of anaesthesia.

It was difficult to judge the onset of a hypnotic effect with pentazocine during induction, although once nystagmus appeared the patient had reached the stage of amnesia. Pentazocine caused a moderate but definite steady elevation of both systolic and diastolic blood pressures throughout surgery, which made it difficult to determine whether adequate anaesthesia existed. However, analgesia was always present. One patient (out of 68) had severe hypertension and a grand mal seizure during induction with pentazocine. If the systolic blood pressure rises more than 25 per cent above the resting level during administration of pentazocine, its use should be abandoned.

Based on these observations, we believe that the use of pentazocine in balanced anaesthesia with or without thiopental induction is unsuitable for major abdominal surgery. Even though the patients awakened rapidly, resumed adequate spontaneous respiration early in most cases, and had benign recovery periods, the overall impression was that the patients were not happy with their anaesthetic. Many objected to the long induction period and several were uncomfortably aware, psychically, of the endotracheal tube and of the surgery, even though they felt no pain.