Comparison of intermittent versus continuous interscalene brachial plexus block for postoperative analgesia

Lee, Hwa Mi; Choi, Woo Jong; Choi, Kyu Taek

Abstract

BACKGROUND
Interscalene brachial plexus block (IBPB) is an effective method of postoperative analgesia after shoulder surgery. This study evaluates the effects and complications of IBPB with two different infusion methods (using intermittent bolus infusion versus automated continuous infusion).
METHODS
Thirty six patients who were scheduled for shoulder surgery were randomly assigned into two groups (the continuous vs. intermittent groups). All the patients received preoperative IBPB using 15 ml of 0.25% ropivacaine followed by insertion of a 20 gauge catheter. This catheter was connected to a patient controlled analgesia (PCA) pump after the operation. The intermittent group (n = 18) received IBPB with 0.2% ropivacaine 100 ml (bolus 15 ml, lock time 4 h) without basal infusion. The continuous group (n = 18) received IBPB with 0.2% ropivacaine 100 ml (basal rate 4 ml/h) without bolus injection. All the patients were given meperidine 25 mg when the postoperative visual analogue score (VAS) >40 mm. The VAS, heart rate, noninvasive blood pressure, respiratory rate, consumption of meperidine and complications were measured during the 64 h following surgery at intervals of 8 h.
RESULTS
The VAS was higher in the intermittent group than that in the continuous group at 24 h after surgery (P < 0.01).However, there was no significant difference for the VAS between the groups for the other assessment periods.There was no significant difference for the amount of meperidine consumed and the incidence of complications between the groups.
CONCLUSIONS
Intermittent IBPB's analgesic effects and complications for treating pain after shoulder surgery are similar to those of continuous IBPB. Therefore, intermittent IBPB could be used for the management of pain after shoulder surgery.