Analgesic Efficacy of Interpleurally Administered Morphine and Fentanyl After Posterolateral Thoracotomy

Pain control is a major concern in post-thoracotomy patients. The current prospective randomized double-blind study was designed to evaluate the analgesic effects of morphine and fentanyl given interpleurally after posterolateral thoracotomy. Thirty patients undergoing elective posterolateral thoracotomy in a teaching hospital in Tehran were divided into 3 groups with equal number of patients. Patients in group IPM, IPF1 and IPF2 received 0.1 mg/kg morphine sulfate, 5 µg/kg fentanyl and 2.5 µg/kg fentanyl in a total volume of 40 ml injected via an intrapleural catheter placed in the pleural space before the closure of chest. Subsequent doses of interpleural injections were administered at 4 and 8 h after operation. The intensity of pain was evaluated at rest and with coughing just before each interpleural injection and 30 min afterwards using a 10 point visual analogue scale (VAS). If patients needed additional analgesia, indomethacin suppository and intravenous morphine were given during the 20-h postoperative study period. In all of the 3 study groups VAS scores were significantly reduced 30 min after interpleural administration of the study solutions (p<0.05). However, inter-group comparisons revealed no significant differences for VSA scores, supplemental analgesic usage and systemic side effects. Briefly, interpleural morphine and fentanyl following thoracotomy produce equal analgesia without major side effects.