title: Speed of onset of 'corner pocket supraclavicular' and infraclavicular ultrasound guided brachial plexus block: a randomised observer-blinded comparison.
abstract: This prospective, randomised, observer blinded study compared the onset time of brachial plexus block using 2% lidocaine 25-30 ml with adrenaline 5 microg.ml(-1) into the 'corner pocket' inferolateral/lateral to the subclavian artery (supraclavicular, n = 30) or to a triple point injection around the axillary artery (infraclavicular, n = 30). Mean (SD) onset time for complete pinprick sensory blockade assessed by a blinded observer in all four distal nerves was similar in both groups: supraclavicular = 22 (9.4) min, infraclavicular = 21 (7.1) min, p = 0.59. Complete sensory blockade in all four nerve territories at 30 min was achieved in 57% in group supraclavicular and 70% in group infraclavicular (p = 0.28). Painless surgery without the requirement for block supplementation was higher in group infraclavicular (28/30, 93%) compared with group supraclavicular (19/30, 67%; p = 0.01). Of the 11 failures in group supraclavicular, nine were due to incomplete ulnar nerve territory anaesthesia. These results do not support the concept of rapid onset successful supraclavicular block via a simple ultrasound-guided local anaesthetic injection inferolateral to the subclavian artery.
authors.affiliation: Auckland City Hospital, University of Auckland, Auckland, New Zealand. fredrickson@actrix.co.nz
authors.forename: M J
authors.initials: MJ
authors.lastname: Fredrickson
authors.forename: A
authors.initials: A
authors.lastname: Patel
authors.forename: S
authors.initials: S
authors.lastname: Young
authors.forename: S
authors.initials: S
authors.lastname: Chinchanwala
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001366:Axillary Artery; D001917:Brachial Plexus / Q000000981:diagnostic imaging*; D005260:Female; D005542:Forearm / Q000601:surgery; D006225:Hand / Q000601:surgery; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000187:drug effects; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D012677:Sensation / Q000187:drug effects; D016037:Single-Blind Method; D013348:Subclavian Artery; D013997:Time Factors; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine