title: Ultrasound guidance with nerve stimulation reduces the time necessary for resident peripheral nerve blockade.
abstract: OBJECTIVE
  Educating residents in peripheral nerve blockade may impact the efficiency of a busy regional anesthesia service. Ultrasound guidance may affect the efficiency and effectiveness of nerve block. We examined the impact of ultrasound guidance on resident performance of peripheral nerve block in a regional anesthesia rotation.
  
  
  METHODS
  An existing de-identified database was used for retrospective analysis of resident performance of interscalene, axillary, femoral, and popliteal nerve blocks, by peripheral nerve stimulator guidance alone and by nerve stimulator aided by ultrasound. The primary variable examined was the time required to perform the block. Others variables included (1) number of needle insertions; (2) proportion of blocks in which there was a blood vessel puncture; and (3) block efficacy. Peripheral nerve-stimulator blocks were guided by surface anatomy and motor stimulation, refined to 0.2 to 0.5 mA of current before injection of local anesthetic, while ultrasound nerve stimulator blocks were confirmed using a current of 0.5 mA.
  
  
  RESULTS
  Ultrasound-aided blocks required less time to perform (median = 1.8 min) than nerve stimulator-guided blocks (median = 6.5 min, P < .001). More needle insertions were required for nerve localization in the nerve stimulator-guided blocks (median = 6) than in ultrasound-aided blocks (median = 2; P < .001). There were fewer blood vessel punctures with ultrasound-aided blocks (P = .03).
  
  
  CONCLUSIONS
  During resident teaching, ultrasound-aided peripheral nerve-stimulated block required less time to perform than did nerve-stimulator-guided blocks. Fewer needle insertions were required to perform the ultrasound-guided blocks, and there were fewer blood vessel punctures when ultrasound was used.
authors.affiliation: Department of Anesthesiology, UPMC-Southside, University of Pittsburgh School of Medicine, Pittsburgh, PA 15203, USA. orebaughsl@aners.upmc.edu
authors.forename: Steven L
authors.initials: SL
authors.lastname: Orebaugh
authors.forename: Brian A
authors.initials: BA
authors.lastname: Williams
authors.forename: Michael L
authors.initials: ML
authors.lastname: Kentor
mesh_terms: D000776:Anesthesiology / Q000193:education*; D016208:Databases, Factual; D004558:Electric Stimulation; D006801:Humans; D007396:Internship and Residency; D019300:Medical Errors / Q000706:statistics & numerical data; D009046:Motor Neurons / Q000000981:diagnostic imaging; D009339:Needles; D009407:Nerve Block; D010525:Peripheral Nerves / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D017211:Treatment Failure; D014463:Ultrasonography