Interscalene brachial plexus block with continuous intraarticular infusionof ropivacaine

Providing intraarticular analgesia with a continuous infusion of local anes thetic via a disposable infusion pump has gained popularity. Despite the pr evalence of this technique, data comparing this method of analgesia to conv entional regional anesthesia are not available. We present a prospective st udy that compared a single-dose interscalene block with a single-dose inter scalene block plus continuous intraarticular infusion of local anesthetic. Forty patients scheduled for shoulder arthroscopy were entered in this pros pective, double-blinded study. All patients received an interscalene brachi al plexus block as their primary anesthetic. Patients were randomly assigne d to 1 of 2 groups: 1. interscalene block with 1.5% mepivacaine (40 mL) fol lowed by a postoperative intraarticular infusion of 0.5% ropivacaine at 2 m L/h, or 2. interscalene block with 0.5% ropivacaine (40 mL) followed by a p ostoperative intraarticular infusion of 0.9% saline (placebo) at 2 mL/h. Po stoperative infusions were maintained for 48 h. Visual analog scale pain sc ores and postoperative oxycodone consumption were measured for 48 h. Visual analog scale scores at rest and with ambulation in the Mepivacaine/Intraar ticular Ropivacaine group were reduced when compared with the Ropivacaine/S aline group (rest: P = 0.003, ambulation: P = 0.006). Oxycodone consumption was also decreased (28 +/- 21 mg vs 44 +/- 28 mg P = 0.046), respectively. We conclude that a brachial plexus block with 1.5% mepivacaine and a conti nuous intraarticular infusion of 0.5% ropivacaine at 2 mL/h provides improv ed analgesia for minor surgery at 24 and 48 h versus a single-injection int erscalene block with 0.5% ropivacaine.