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.