title: Ultrasound-guided block of the axillary nerve: a volunteer study of a new method.
abstract: BACKGROUND
  Interscalene brachial plexus block (IBPB) is the gold standard for perioperative pain management in shoulder surgery. However, a more distal technique would be desirable to avoid the side effects and potential serious complications of IBPB. Therefore, the aim of the present study was to develop and describe a new method to perform an ultrasound-guided specific axillary nerve block.
  
  
  METHODS
  After initial investigations, 12 healthy volunteers were included. We performed an in-line ultrasound-guided specific axillary nerve block by injecting 8 ml local anesthetic (lidocaine 20 mg/ml) after placing the tip of a nerve stimulation needle cranial to the posterior circumflex humeral artery in the neurovascular space bordered by the teres minor muscle, the deltoid muscle, the triceps muscle and the shaft of the humerus. Needle placement was aided by simultaneous nerve stimulation. We assessed sensory (pinprick and cold stimulation) and motor (active resistive force) block of the axillary nerve before, 15, 30, 60, 90 and 120 min after performing the block and every 30 min until termination of the block.
  
  
  RESULTS
  All 12 volunteers demonstrated sensory block of the axillary nerve and 10 volunteers demonstrated complete motor block. Even though it was difficult to directly visualize the axillary nerve, the block was easy to perform with easily recognizable ultrasonographic landmarks. Block duration was approximately 120 min.
  
  
  CONCLUSIONS
  We describe a new ultrasound-guided technique to specifically block the axillary nerve. The potential clinical role of this new block remains to be determined.
authors.affiliation: Department of Anesthesia and Intensive Care, Hillerød Hospital, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Rothe
authors.forename: S
authors.initials: S
authors.lastname: Asghar
authors.forename: H L
authors.initials: HL
authors.lastname: Andersen
authors.forename: J K
authors.initials: JK
authors.lastname: Christensen
authors.forename: K H W
authors.initials: KH
authors.lastname: Lange
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage; D001917:Brachial Plexus / Q000000981:diagnostic imaging*; D003080:Cold Temperature; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000294:innervation; D009407:Nerve Block / Q000379:methods*; D010525:Peripheral Nerves / Q000033:anatomy & histology; D010812:Physical Stimulation; D012677:Sensation / Q000187:drug effects; D012785:Shoulder Joint / Q000033:anatomy & histology / Q000294:innervation; D014463:Ultrasonography
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine