title: A prospective, randomized comparison between single- and double-injection ultrasound-guided infraclavicular brachial plexus block.
abstract: BACKGROUND
  This prospective, randomized, observer-blinded study compared single- and double-injection ultrasound-guided infraclavicular brachial plexus block for upper extremity surgery.
  
  
  METHODS
  Eighty-eight patients were randomly allocated to receive a single-injection (n = 44) or double-injection (n = 44) ultrasound-guided infraclavicular block. The main outcome variable was the onset time. A blinded observer recorded the onset time, block-related pain scores, success rate (surgical anesthesia), and the incidence of complications. Performance time (defined as the sum of imaging and needling times) and the number of needle passes were also recorded during the performance of the block. The total anesthesia-related time was defined as the sum of the performance and onset times.
  
  
  RESULTS
  No differences in imaging, needling, performance, and onset and total anesthesia-related times were found between the 2 groups. There were no differences in the rate of surgical anesthesia (93.1%-97.7%). The number of needle passes was also similar; however, the double-injection technique resulted in slightly less procedural discomfort (1.1 [SD, 1.6] vs 2.1 [SD, 2.1]; P = 0.021). There were no differences in the incidence of adverse events.
  
  
  CONCLUSIONS
  The double-injection ultrasound-guided infraclavicular block provides no significant advantages compared with its single-injection counterpart.
authors.affiliation: Montreal General Hospital, Department of Anesthesia, McGill University, Montreal, Quebec, Canada. de_tran@hotmail.com
authors.forename: De Q H
authors.initials: DQ
authors.lastname: Tran
authors.forename: Pietro
authors.initials: P
authors.lastname: Bertini
authors.forename: Cedrick
authors.initials: C
authors.lastname: Zaouter
authors.forename: Loreto
authors.initials: L
authors.lastname: Muñoz
authors.forename: Roderick J
authors.initials: RJ
authors.lastname: Finlayson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001917:Brachial Plexus / Q000000981:diagnostic imaging; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009339:Needles; D009407:Nerve Block / Q000295:instrumentation / Q000379:methods*; D010147:Pain Measurement; D011446:Prospective Studies; D016037:Single-Blind Method; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D034941:Upper Extremity / Q000601:surgery*; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D004837:Epinephrine