Personality assessment and postoperative analgesia. A study in male patients undergoing elective gastric surgery.

In 40 patients undergoing surgery for duodenal ulcer, personality was assessed by a PEN Inventory. After operation, the respiratory restoration factor (RRF) was used to indicate the pain relief from nitrous oxide (25%) and i.v. methadone (three doses of 2 mg). There was no correlation between the psychological factors and RRF. Twenty-five per cent nitrous oxide appeared to be equivalent to i.v. methadone 4 mg in terms of RRF. The degree of hypoxia after surgery correlated with vital capacity impairment and the improvement of oxygen tension after analgesia correlated with RRF after methadone 6 mg.