Effective analgesia with ultrasound-guided interscalene brachial plexus block for postoperative pain control after arthroscopic rotator cuff repair

Abstract

Ultrasound (US)-guided continuous interscalene brachial plexus block (CBPB) is known to provide effective pain relief for arthroscopic rotator cuff repair. This study was conducted to compare analgesic efficacy and forearm muscle tone of the basal infusion rate and bolus dose of 0.2 % ropivacaine for US-guided CBPB with intravenous patient-controlled analgesia (IV-PCA). In a prospective trial, 99 patients scheduled to undergo arthroscopic rotator cuff repair were divided into three groups. In groups A and B, an US-guided 17-gauge Tuohy needle was inserted into the interscalene brachial plexus. A loading dose of 10 ml 0.2 % ropivacaine was administered via the needle. A 19-gauge perineural catheter was then inserted through the needle and advanced to a depth of 1.5 cm beyond the needle tip between the C5 and C6 nerve trunks. After surgery, groups A and B received a continuous infusion of 0.2 % ropivacaine at 4 or 0 ml/h, a bolus of 0 or 4 ml, and a lockout time of 60 min through the catheter, respectively. Group C received IV-PCA. Pain scores and the forearm muscle tone of patients were compared using a numeric rating scale (NRS), rates of patients taking supplementary opioid analgesics, and manual muscle test (MMT) scoring. The NRS scores and rate of patients taking supplementary opioid analgesics in groups A and B were lower than those in group C after surgery. Groups A and B showed similar clinical efficacy. There were no significant differences in MMT scoring among the three groups. The bolus dose of 0.2 % ropivacaine using US-guided CBPB would provide equivalent analgesic efficacy comparable with the basal infusion and motor weakness comparable with IV-PCA after arthroscopic rotator cuff repair.