title: Electrical stimulation versus ultrasound guidance for popliteal-sciatic perineural catheter insertion: a randomized controlled trial.
abstract: BACKGROUND
  Sciatic perineural catheters via a popliteal fossa approach and subsequent local anesthetic infusion provide potent analgesia and other benefits after foot and ankle surgery. Electrical stimulation (ES) and, more recently, ultrasound (US)-guided placement techniques have been described. However, because these techniques have not been compared in a randomized fashion, the optimal method remains undetermined. Therefore, we 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.
  
  
  METHODS
  Preoperatively, subjects receiving a popliteal-sciatic perineural 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 (10th-90th percentile) of 5.0 min (3.9-11.1 min) compared with 10.0 min (2.0-15.0 min) for stimulation (P = 0.034). Subjects in the US group experienced less pain during catheter placement, scoring discomfort a median of 0 (0.0-2.1) compared with 2.0 (0.0-5.0) 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.
authors.affiliation: Department of Anesthesiology, University of California, San Diego Medical Center, San Diego, CA, USA.
authors.forename: Edward R
authors.initials: ER
authors.lastname: Mariano
authors.forename: Gloria S
authors.initials: GS
authors.lastname: Cheng
authors.forename: Lynna P
authors.initials: LP
authors.lastname: Choy
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Loland
authors.forename: Richard H
authors.initials: RH
authors.lastname: Bellars
authors.forename: Navparkash S
authors.initials: NS
authors.lastname: Sandhu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Bishop
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Lee
authors.forename: Rosalita C
authors.initials: RC
authors.lastname: Maldonado
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
mesh_terms: D000328:Adult; D000842:Ankle / Q000601:surgery; D002404:Catheterization / Q000009:adverse effects; D004558:Electric Stimulation / Q000009:adverse effects; D005260:Female; D005528:Foot / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D009407:Nerve Block / Q000379:methods*; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D017060:Patient Satisfaction; D012584:Sciatic Nerve / Q000000981:diagnostic imaging*; D013997:Time Factors; D018084:Ultrasonography, Interventional / Q000009:adverse effects