Comparison of paravertebral and interpleural block in patients undergoing modified radical mastectomy

Background: Paravertebral and inter pleural blocks (IPB) reduce post-operative pain and decrease the effect of post-operative pain on lung functions after breast surgery. This study was designed to determine their effect on lung functions and post-operative pain in patients undergoing modified radical mastectomy.

Materials and methods: A total of 120 American Society of Anesthesiologists physical status 1 and 2 patients scheduled to undergo breast surgery were randomly allocated to receive IPB (Group IPB, n = 60) or paravertebral block (PVB) (Group PVB, n = 60) with 20 ml of 0.5% bupivacaine pre-operatively. A standard protocol was used to provide general anesthesia. Lung function tests, visual analog scale (VAS) for pain at rest and movement, analgesic consumption were recorded everyday post-operatively until discharge.

Results: Lung functions decreased on 1(st) post-operative day and returned to baseline value by 4(th) post-operative day in both groups. VAS was similar in both groups. There was no significant difference in the consumption of opioids and diclofenac in both groups. Complete block was achieved in 48 patients (80%) in paravertebral group and 42 patients (70%) in inter pleural group.

Conclusion: To conclude, lung functions are well-preserved in patients undergoing modified radical mastectomy under general anesthesia supplemented with paravertebral or IPB. IPB is as effective as PVB for post-operative pain relief. PVB has the added advantage of achieving a more complete block.