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Background: Although the efficacy of single-injection supraclavicular nerve blocks is well established, no controlled study of continuous supraclavicular blocks is available, and their relative risks and benefits remain unknown. In contrast, the analgesia provided by continuous infraclavicular nerve blocks has been validated in randomized controlled trials. We therefore compared supraclavicular with infraclavicular perineural local anesthetic infusion following distal upper-extremity surgery., Methods: Preoperatively, subjects were randomly assigned to receive a brachial plexus perineural catheter in either the infraclavicular or supraclavicular location using an ultrasound-guided nonstimulating catheter technique. Postoperatively, subjects were discharged home with a portable pump (400-mL reservoir) infusing 0.2% ropivacaine (basal rate of 8 mL/hr; 4-mL bolus dose; 30-min lockout interval). Subjects were followed up by telephone on an outpatient basis. The primary outcome was the average pain score on the day after surgery., Results: Sixty subjects were enrolled, with 31 and 29 randomized to receive an infraclavicular and supraclavicular catheter, respectively. All perineural catheters were successfully placed per protocol. Because of protocol violations and missing data, an intention-to-treat analysis was not used; rather, only subjects with catheters in situ and whom we were able to contact were included in the analyses. The day after surgery, subjects in the infraclavicular group reported average pain as median of 2.0 (10th-90th percentiles, 0.5-6.0) compared with 4.0 (10th-90th percentiles, 0.6-7.7) in the supraclavicular group (P = 0.025). Similarly, least pain scores (numeric rating scale) on postoperative day 1 were lower in the infraclavicular group compared with the supraclavicular group (0.5 [10th-90th percentiles, 0.0-3.5] vs 2.0 [10th-90th percentiles, 0.0-4.7], respectively; P = 0.040). Subjects in the infraclavicular group required less rescue oral analgesic (oxycodone, in milligrams) for breakthrough pain in the 18 to 24 hrs after surgery compared with the supraclavicular group (0.0 [10th-90th percentiles, 0.0-5.0] vs 5.0 [10th-90th percentiles, 0.0-15.0], respectively; P = 0.048). There were no statistically significant differences in other secondary outcomes., Conclusions: A local anesthetic infusion via an infraclavicular perineural catheter provides superior analgesia compared with a supraclavicular perineural catheter.

Objective: Compared to the well-established stimulating catheter technique, the use of ultrasound guidance alone for interscalene perineural catheter insertion is a recent development and has not yet been examined in a randomized fashion. We hypothesized that an ultrasound-guided technique would require less time and produce equivalent results compared to electrical stimulation (ES) when trainees attempt interscalene perineural catheter placement., Methods: Preoperatively, patients receiving an interscalene perineural catheter for shoulder surgery were randomly assigned to an insertion protocol using either ultrasound guidance with a nonstimulating catheter or ES with a stimulating catheter. The primary outcome was the procedural duration (in minutes), starting when the ultrasound probe (ultrasound group) or catheter insertion needle (ES group) first touched the patient and ending when the catheter insertion needle was removed after catheter insertion., Results: All ultrasound-guided catheters (n = 20) were placed successfully and resulted in surgical anesthesia versus 85% of ES-guided catheters (n = 20; P = .231). Perineural catheters placed by ultrasound (n = 20) took a median (10th-90th percentiles) of 8.0 (5.0-15.5) minutes compared to 14.0 (5.0-30.0) minutes for ES (n = 20; P = .022). All catheters placed according to the protocol in both treatment groups resulted in a successful nerve block; however, 1 patient in the ES group had local anesthetic spread to the epidural space. There was 1 vascular puncture using ultrasound guidance compared to 5 in the ES-guided catheter group (P = .182)., Conclusions: Trainees using a new ultrasound-guided technique can place inter-scalene perineural catheters in less time compared to a well-documented technique using ES with a stimulating catheter and can produce equivalent results.

Objective: Electrical stimulation (ES)- and ultrasound-guided placement techniques have been described for infraclavicular brachial plexus perineural catheters but to our knowledge have never been previously compared in a randomized fashion, leaving the optimal method undetermined. We tested the hypothesis that infraclavicular catheters placed via ultrasound guidance alone require less time for placement and produce equivalent results compared with catheters placed solely via ES., Methods: Preoperatively, patients receiving an infraclavicular perineural catheter for distal upper extremity surgery were randomly assigned to either ES with a stimulating catheter or ultrasound guidance with a nonstimulating catheter. The primary outcome was the catheter insertion duration (minutes) starting when the ultrasound transducer (ultrasound group) or catheter placement needle (stimulation group) first touched the patient and ending when the catheter placement needle was removed after catheter insertion., Results: Perineural catheters placed with ultrasound guidance took a median (10th-90th percentile) of 9.0 (6.0-13.2) minutes compared with 15.0 (4.9-30.0) minutes for stimulation (P < .01). All ultrasound-guided catheters were successfully placed according to the protocol (n = 20) versus 70% in the stimulation group (n = 20; P < .01). All ultrasound-guided catheters resulted in a successful surgical block, whereas 2 catheters placed by stimulation failed to result in surgical anesthesia. Six catheters (30%) placed via stimulation resulted in vascular punctures compared with none in the ultrasound group (P < .01). Procedure-related pain scores were similar between groups (P = .34)., Conclusions: Placement of infraclavicular perineural catheters takes less time, is more often successful, and results in fewer inadvertent vascular punctures when using ultrasound guidance compared with ES.