Copyright @ 2009 . Unauthorized reproduction of this article is prohibited. American Society of Regional Anesthesia and Pain Medicine Electrical Stimulation Versus Ultrasound Guidance for Popliteal-Sciatic Perineural Catheter Insertion A Randomized Controlled Trial Edward R. Mariano, MD, MAS,* Gloria S. Cheng, MD,* Lynna P. Choy, MD,* Vanessa J. Loland, MD,* Richard H. Bellars, MD,* NavParkash S. Sandhu, MD,* Michael L. Bishop, MD,* Daniel K. Lee, DPM, FACFAS,Þ Rosalita C. Maldonado, BS,* and Brian M. Ilfeld, MD, MS* Background: Sciatic perineural catheters via a popliteal fossa ap- proach and subsequent local anesthetic infusion provide potent analgesia and other benefits after foot and ankle surgery. Electrical stimulation (ES) and, more recently, ultrasound (US)Yguided placement techniques have been described. However, because these techniques have not been com- pared in a randomized fashion, the optimal method remains undeter- mined. Therefore, we tested the hypotheses that popliteal-sciatic perineural catheters placed via US guidance require less time for place- ment and produce equivalent results, as compared with catheters placed using ES. Methods: Preoperatively, subjects receiving a popliteal-sciatic peri- neural catheter for foot and/or ankle surgery were randomly assigned to either the ES with a stimulating catheter or US-guided technique with a nonstimulating catheter. The primary end point was catheter insertion duration (in minutes) starting when the US transducer (US group) or catheter-placement needle (ES group) first touched the patient and ending when the catheter-placement needle was removed after catheter insertion. Results: All US-guided catheters were placed per protocol (n = 20), whereas only 80% of stimulation-guided catheters could be placed per protocol (n = 20, P = 0.106). All catheters placed per protocol in both groups resulted in a successful surgical block. Perineural catheters placed by US took a median (10thY90th percentile) of 5.0 min (3.9Y11.1 min) compared with 10.0 min (2.0Y15.0 min) for stimulation (P = 0.034). Subjects in the US group experienced less pain during catheter placement, scoring discomfort a median of 0 (0.0Y2.1) com- pared with 2.0 (0.0Y5.0) for the stimulation group (P = 0.005) on a numeric rating scale of 0 to 10. Conclusions: Placement of popliteal-sciatic perineural catheters takes less time and produces less procedure-related discomfort when using US guidance compared with ES. (Reg Anesth Pain Med 2009;34: 480Y485) P opliteal-sciatic continuous peripheral nerve blocks (CPNBs) provide potent analgesia and other benefits after foot and ankle surgery, as documented by previous randomized con- trolled investigations. 1,2 Most perineural catheter reports from the previous 2 decades have used electrical stimulation (ES) to locate the target nerve via an insulated needle, followed by insertion of either a nonstimulating or stimulating catheter. More recently, ultrasound (US)Yguided perineural catheter placement has been described. 3Y5 While ES- and US-guided techniques have been directly compared for single-injection peripheral nerve block placement (and suggest possible advantages with US in block placement time, success rates, and patient comfort), 6 no comparison for perineural catheter placement is available. As such, the optimal catheter-placement method and any possible benefits of one technique over the other remain undetermined. We therefore tested the hypotheses that popliteal-sciatic perineural catheters placed via US guidance require less time for placement and produce equivalent results, as compared with catheters placed using ES. The primary outcome was catheter insertion duration (in minutes) starting when the US probe (US group) or catheter-placement needle (ES group) first touched the patient and ending when the catheter-placement needle was removed after perineural catheter insertion. METHODS The institutional review board (University of California, San Diego School of Medicine, San Diego, Calif) approved the protocol and oversaw the study through data analysis. Patients offered enrollment included adults (Q18 years) scheduled for at least moderately painful orthopedic surgery of the foot and/or ankle who desired, and were approved for, a popliteal-sciatic CPNB for postoperative analgesia. Exclusion criteria included known neuropathy of any etiology in the surgical extremity; preg- nancy; incarceration; and inability to communicate with the in- vestigators and hospital staff. Protocol After written, informed consent, subjects were randomized to 1 of 2 treatment groupsVES or US guidanceVusing a computer- generated randomization table based in a secure, password- protected, encrypted central server (www.PAINfRE.com; General ULTRASOUND ARTICLE 480 Regional Anesthesia and Pain Medicine & Volume 34, Number 5, September-October 2009 From the Departments of *Anesthesiology and †Orthopedic Surgery, University of California, San Diego Medical Center, San Diego, CA. Accepted for publication November 4, 2008. Address correspondence to: Brian M. Ilfeld, MD, MS, Department of Anesthesiology, University of California, San Diego, Center for Pain Medicine, 9300 Campus Point Dr, MC 7651, La Jolla, CA 92037-7651 (e-mail: bilfeld@ucsd.edu). Reprints will not be available from the authors. Funding for this project was provided by National Institutes of Health grant GM077026 (principal investigator: Dr. Ilfeld) from the National Institute of General Medical Sciences (Bethesda, Md) and the Department of Anesthesiology, University of California, San Diego Medical Center (San Diego, Calif ). A portion of the results of this investigation was presented at the Annual Meeting of the American Society of Anesthesiologists; October 18Y22, 2008; Orlando, Fla. Drs. Mariano, Loland, and Ilfeld and Ms. Maldonado have received funding for other research investigations from Arrow International (Reading, Pa) and Stryker Instruments (Kalamazoo, Mich). These companies had absolutely no input into any aspect of the present study conceptualization, design, and implementation; data collection, analysis, and interpretation; or manuscript preparation. Drs. Mariano and Loland conduct continuous peripheral nerve block workshops for Stryker Instruments. None of the other authors have any personal financial interest in this research. Copyright * 2009 by American Society of Regional Anesthesia and Pain Medicine ISSN: 1098-7339 DOI: 10.1097/AAP.0b013e3181ada57a