Abstract ID: A21
Abstract Title: Interscalene Brachial Plexus Block Results In Superior Postoperative Analgesia Compared To GA Plus Wound Infiltration As Sole Technique For Outpatient Rotator Cuff Surgery
Poster Type: Either
ABSTRACT BODY
Introduction: Postoperative pain associated with outpatient rotator cuff repair (RCR) often interferes with initial recovery and rehabilitation. An opioid-free analgesic regimen devoid of nausea, vomiting, and somnolence should be advantageous in this setting. Interscalene brachial plexus block (ISB) can provide complete anesthesia for outpatient shoulder surgery, however, well-controlled clinical studies comparing ISB versus general anesthesia (GA) have not been done in this setting. Our hypothesis is that ISB provides superior analgesia to GA followed by wound infiltration in patients having outpatient RCA.
Materials and Methods: Following IRB approval, eligible patients (ages 18 to 70 years [n=50], ASA physical status I-III, and scheduled for outpatient RCR) were recruited and written informed consent obtained. Patients were randomly assigned to receive either ISB or “fast-track” GA using standardized protocols [ISB: 35-40 ml of 0.75% ropivacaine, intraoperative sedation with propofol titrated to patient comfort; GA: dolasetron 12.5 mg, midazolam (1-2 mg), and fentanyl (50-100 µg), propofol (2.5 mg/kg), rocuronium (1 mg/kg), endotracheal intubation, desflurane in oxygen/nitrous oxide (50:50) + intravenous boluses of fentanyl (25-50 mcg)]. Patients having GA had the incision infiltrated with 5-10 ml 0.25% bupivacaine and an intra-articular injection of 10-15 ml 0.25% bupivacaine. At the conclusion of the procedure, PACU nurses, unaware of the anesthetic technique used, evaluated patients using a modified Aldrete score. In Phase 1 PACU, IV morphine (1-2 mg) was administered if necessary every 5-10 minutes until the patient was comfortable (VAS score ≤ 2). The pain management protocol in Phase 2 PACU and at home consisted of acetaminophen with codeine (325 mg/30 mg) every 4 hours as needed. VAS scores and quantity of analgesics taken were collected by a blinded research assistant at time of discharge and by telephone interview at 24, 48 and 72 hours after surgery.
Results: Fifty patients were randomized to either the GA or ISB groups. Patients (25 in each group) were evenly distributed by sex, age, height, weight and ASA physical status. Patients in the ISB group had a significantly better immediate post-op analgesia profile and less side-effects compared with the GA group (Figure 1). Four patients (all in the GA group) were subsequently admitted for pain management (p=0.05). During the telephone follow-up phase, no difference was found between GA and ISB groups for VAS scores or analgesic requirements at 24, 48 and 72 hours.
Discussion: ISB provided superior analgesia with fewer side-effects in the immediate postoperative period after RCR, compared to GA + wound infiltration. However, both groups had a similar degree of discomfort after 24 hours. Although the analgesic advantages appeared to have been limited to the duration of the blockade, a common notion that patients receiving ISB may experience a greater discomfort when the block wears off then those receiving GA did not prove true in our model. More studies are indicated to determine whether continuous infusion of local anesthetic via an indwelling ISB catheter can reliably and safely extend the analgesic benefits of the single injection ISB after outpatient RCR surgery.
ATTACHED FILES
A21_Figure 1.doc
Reg Anesth Pain Med 2004; 29(2):A21