Postoperative analgesia after modified radical mastectomy: the efficacy of interscalene brachial plexus block

Abstract

In the present study, we evaluated the effects of interscalene brachial plexus block on postoperative pain relief and morphine consumption after modified radical mastectomy (MRM). Sixty ASA I-III patients scheduled for elective unilateral MRM under general anesthesia were included. They were randomly allocated into two groups: group 1 (n = 30), single-injection ipsilateral interscalene brachial plexus block; group 2 (n = 30), control group. Postoperative analgesia was provided with IV PCA morphine during 24 h postoperatively. Pain intensity was assessed with the visual analogue scale (VAS). Morphine consumption, side effects of opioid, antiemetic requirement, and complications associated with interscalene block were recorded. VAS scores were significantly lower in group 1, except in the first postoperative 24 h (p < 0.007). The patients without block consumed more morphine [group 1, 5 (0-40) mg; group 2, 22 (6-48) mg; p = 0.001]. Rescue morphine requirements were also higher in the postoperative first hour in group 2 (p = 0.001). Nausea and antiemetic requirements were significantly higher in group 2 (p = 0.03 and 0.018). Urinary retention was observed in 1 patient in group 2 and signs of Horner's syndrome in 2 patients in group 1. The optimal method has not been defined yet for acute pain palliation after MRM. Our study demonstrated that the use of interscalene block in patients undergoing MRM improved pain scores and reduced morphine consumption during the first 24 h postoperatively. The block can be a good alternative to other invasive regional block techniques used for postoperative pain management after MRM.