title: Ultrasound provides a reliable test of local anesthetic spread.
abstract: OBJECTIVE
  We predicted that practitioners could identify injectate spread in a model of ultrasound-guided peripheral nerve block.
  
  
  METHODS
  Both novices and experts in ultrasound-guided peripheral nerve block were asked to recognize the spread of local anesthetic in a gelatin ultrasound phantom. In a blinded and randomized fashion, these participants were observed to either successfully or unsuccessfully state whether an injection had been made.
  
  
  RESULTS
  Twelve novices and 8 experts each completed the trials. Accuracy, Sensitivity and specificity were calculated for all trials. Users attained a very high accuracy and sensitivity (> 85%) as well as specificity (> 90%) with ultrasound in this model.
  
  
  CONCLUSIONS
  This study shows that ultrasound is a reliable method of detecting injectate spread in a gelatin phantom model.
authors.affiliation: Department of Anesthesia, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, Ontario M4N3M5, Canada. colin.mccartney@utoronto.ca
authors.forename: Colin J L
authors.initials: CJ
authors.lastname: McCartney
authors.forename: Victoria
authors.initials: V
authors.lastname: Dickinson
authors.forename: Adam
authors.initials: A
authors.lastname: Dubrowski
authors.forename: Sheila
authors.initials: S
authors.lastname: Riazi
authors.forename: Paul
authors.initials: P
authors.lastname: McHardy
authors.forename: Imad T
authors.initials: IT
authors.lastname: Awad
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage*; D002983:Clinical Competence; D005780:Gelatin; D006801:Humans; D007267:Injections; D009407:Nerve Block; D009864:Ontario; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional / Q000295:instrumentation
chemical_list: D000779:Anesthetics, Local; D005780:Gelatin