Balanced anesthesia: a comparison of butorphanol and morphine.

We did a retrospective study to compare butorphanol with morphine for use in a balanced anesthetic technique with nitrous oxide, oxygen, and neuromuscular relaxants. Patient records were reviewed for preoperative, intraoperative, and postoperative arterial blood gas values and vital signs; postoperative analgesia, nausea, vomiting, hallucinations, and dysphoria; and patient recall of the procedure. Patients in the butorphanol group proved to have less postoperative respiratory depression as determined by arterial carbon dioxide tension on arrival in the recovery room (42.8 mm Hg vs 51.1 mm Hg). The patients who received butorphanol also had less nausea (8.3% vs 44.4%) and less vomiting (8.3% vs 33.3%) than those given morphine. Neither group had any recall of procedure, hallucination, or dysphoria as determined by postoperative interview.