For analgesic action of short duration during anesthtic periods (premedication dinduction and maintenance) and in the immediate postoperative period as need arises. As a narcotic analgesic supplement in general or regional anesthesia. For administration with neuroleptics (such as droperidol) as an anesthetic premedication for the induction of anesthesia and as an adjunct in the maintenance of general or regional anesthesia. For use as an anesthetic agent with oxygen in selected high-risk patients (open heart surgery or certain neurological or orthopedic procedures). By the epidural route for the postoperative management of pain following general surgical procedures and cesarean sections and as adjunct to general anesthesia.