A Trainee-Based Randomized Comparison of Stimulating Interscalene Perineural Catheters With a New Technique Using Ultrasound Guidance Alone

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 interscalene perineural catheters in less time compared to a well-documented technique using ES with a stimulating catheter and can produce equivalent results.