title: Compared with dual nerve stimulation, ultrasound guidance shortens the time for infraclavicular block performance.
abstract: OBJECTIVE
  The success rate for infraclavicular brachial plexus block using nerve stimulation reportedly ranges from 60 to 80%. Ultrasound guidance may be associated with greater success. This study compared ultrasound guided infraclavicular block with a dual motor endpoint nerve stimulation technique.
  
  
  METHODS
  One hundred three hand surgery patients were randomized to receive either ultrasound-guided (ultrasound group) or dual motor endpoint nerve stimulation (stimulation group) infraclavicular block using 2% lidocaine 15 mL and 0.5% bupivacaine 15 mL with epinephrine. Block success was defined as loss of sensation to pinprick in each of the radial, ulnar, median, and musculocutaneous nerve distributions when measured 20 min after block performance. Block performance time, readiness for surgery (no supplemental block, skin infiltration, or general anesthesia), and complications were also assessed.
  
  
  RESULTS
  Patient characteristics were similar between groups. Success rate was 92% in the ultrasound group and 80% in the stimulation group (P = 0.18). Block performance time was shorter in the ultrasound group (median 5 min) compared with the stimulation group (median 10.5 min) (P < 0.001). Paresthesiae were more frequent in the stimulation group (45%) than in the ultrasound group (6%) (P < 0.001). After final injection, more patients were ready for surgery in the ultrasound group (85%) than in the stimulation group (65%) (P = 0.04). At 1 week postoperatively, complications were minor and transient and did not differ between groups.
  
  
  CONCLUSIONS
  There was no statistically significant difference in the success rate between ultrasound guidance and dual motor endpoint stimulation for infraclavicular block. However, ultrasound guidance shortens performance time and improves readiness for surgery compared with dual motor endpoint stimulation.
authors.affiliation: Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada. richard.brull@uhn.on.ca
authors.forename: Richard
authors.initials: R
authors.lastname: Brull
authors.forename: Mario
authors.initials: M
authors.lastname: Lupu
authors.forename: Anahi
authors.initials: A
authors.lastname: Perlas
authors.forename: Vincent W S
authors.initials: VW
authors.lastname: Chan
authors.forename: Colin J L
authors.initials: CJ
authors.lastname: McCartney
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage; D001917:Brachial Plexus; D002045:Bupivacaine / Q000008:administration & dosage; D004311:Double-Blind Method; D004558:Electric Stimulation / Q000009:adverse effects / Q000379:methods*; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D011183:Postoperative Complications; D011446:Prospective Studies; D013997:Time Factors; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine; D004837:Epinephrine