Comparison of the Effects of Intrapleural Bupivacaine and Morphine on Post-thoracotomy Pain.

BACKGROUND Post-thoracotomy pain is the most severe types of postoperative pain. This study compares the effects of intrapleural bupivacaine and morphine on post-thoracotomy pain. METHODS In a double blind clinical trial study, 30 patients candidate for unilateral thoracotomy were randomly divided into bupivacaine and morphine groups. Patients in the morphine group received 0.2 mg/kg morphine and those in the bupivacaine group received 1 mg/kg bupivacaine by an intrapleural catheter placed at the end of surgery by direct vision. Intrarpleural morphine and bupivacaine continued every 4 hours for the next 24 hours. If required, systemic analgesia with morphine (patient-controlled analgesia, PCA) also used as a postoperative analgesic. The amount of morphine consumption and level of postoperative pain at 2, 6, 12 and 24 hours after surgery were recorded. RESULTS Patients did not differ significantly in terms of age, gender and duration of surgery. There were no significant differences between the two groups with regard to their mean score of pain at 2 and 6 hours of the surgery; however, the level of pain was significantly lower in the bupivacaine group compared to the morphine group at 12 and 24 hours of the surgery. In the bupivacaine group, the mean level of intravenous opioid used over the 24 hours following surgery was significantly lower than in the morphine group. DISCUSSION Intrapleural injection of bupivacaine can be more effective in reducing post-thoracotomy pain compared to intrapleural morphine.