Introduction: Pain is one of the most common postoperative complaints in any type of surgery and has negative effects on all aspects of patients' functions, including psychiatric and somatic functions. Post-thoracotomy pain is commonly very severe and induces complications such as atelectasia. It affects pulmonary function. Different ways of pain control have been studied before and mutually compared. In the present study we compare four methods of post-thoracotomy pain control with emphasis on pulmonary function tests.

Methods: 100 ASA physical status I & II patients scheduled for posterolateral thoracotomy were included in this study. The patients were randomized into one of the four groups (25 patients in each group): every 6 hours group A received fentanyl via epidural catheter every, group B received 0.25% bupiavacain via epidural catheter, group C were administered 0.25% bupivacain via inter-costal catheter, and group D received intravenous meperidine. Pain was assessed every 6 hours (15 minutes before medication injection) using visual analogue five-grade scale. Pulmonary function indexes were measured before and 72 hours after surgery.

Results: The mean of pain were different among the four groups ( p≈ 0.00). In group C mean of pain was less than group A by 0.77( p= 0.001) & in group D was less than group A by 0.54 score ( p= 0.04) . There were no significant differences in pain score among other groups. In group D the petedine requsted were less than A, B & C groups by 61.9mg, 46.6mg & 46.6mg ( p≈ 0.00). There was less FEV₁/ FVC reduction in group B, but this reduction is not statistically significant. Also FEV₁/ FVC ratio are significantly different among groups ( p= 0.001)

Conclusion: The study shows that intercostal injection of 0.5 ml/kg 0.25% Bupivacain or intravenous injection of 0.5 mg/kg Meperidine every 6 hours has better efficacy for post-thoracotomy pain relief in comparison with the other studied methods.

Hakim Research Journal 2007 9(4): 46- 51.