Comparison of different methods of postoperative analgesia after thoracotomy

Abstract

Fifty-one patients scheduled for thoracotomy were included in a study involving five different methods of postoperative analgesia. Forty patients were randomly divided into: Group C, receiving intramuscular oxycodone on request following an intraoperative intercostal block; Group IC, intercostal blocks with 0.5% bupivacaine performed prior to surgery, 6 h later and on the first postoperative morning: Group EB, epidural bupivacaine as a continuous infusion of 0.25% bupivacaine (5 ml h-1); Group EM4 epidural morphine 4 mg injected prior to surgery and on the first postoperative morning. In addition, a fifth group (Group EM6) of 11 patients received 6 mg of epidural morphine timed as in Group EM4, but these patients were automatically scheduled to be observed in the ICU. Additional intramuscular oxycodone was given on request to all patients. Group EB, EM4 and EM6 had lower numbers of requests than Group C. Pain intensity score was lowest (2.5 on a scale from 0 to 10, 3 h postoperatively) in Group EM6, and there was a statistically significant difference in pain intensity at 3 h between EM4 and EM6. The evaluation of cooperation and pain by the physical therapist revealed no differences between the groups. Postoperatively, only Group EB was devoid of PCO2 values above 7.3 kPa. Urinary retention was a common complication in the patients receiving epidural analgesia, occurring most frequently in Group EM6; 10 of the 11 patients had to be catheterized.