title: Assessment of brachial plexus blockade in chickens by an axillary approach.
abstract: OBJECTIVE
  To assess the brachial plexus block in chickens by an axillary approach and using a peripheral nerve stimulator.
  
  
  METHODS
  Prospective, randomized, double-blinded study.
  
  
  METHODS
  Six, 84-week old, female chickens.
  
  
  METHODS
  Midazolam (1 mg kg(-1)) and butorphanol (1 mg kg(-1)) were administered into the pectoralis muscle. Fifteen minutes later, the birds were positioned in lateral recumbency and following palpation of the anatomic landmarks, a catheter was inserted using an axillary approach to the brachial plexus. Lidocaine or bupivacaine (1 mL kg(-1)) was injected after plexus localization by the nerve stimulator. Sensory function was tested before and after blockade (carpus, radius/ulna, humerus and pectoralis muscle) in the blocked and unblocked wings. The latency to onset of motor and sensory block and the duration of sensory block were recorded. A Friedman nonparametric one-way repeated-measures ANOVA was used to compare scores from baseline values over time and to compare the differences between wings at each time point.
  
  
  RESULTS
  A total of 18 blocks were performed with a success rate of 66.6% (12/18). The latency for motor block was 2.8 +/- 1.1 and 3.2 +/- 0.4 minutes for lidocaine and bupivacaine, respectively. The latencies for and durations of the sensory block were 6.0 +/- 2.5 and 64.0 +/- 18.0 and 7.8 +/- 5.8 and 91.6 +/- 61.7 minutes for lidocaine and bupivacaine, respectively. There was no statistical difference between these times for lidocaine or bupivacaine. Sensory function was not abolished in nonblocked wings.
  
  
  CONCLUSIONS
  The brachial plexus block was an easy technique to perform but had a high failure rate. It might be useful for providing anesthesia or postoperative analgesia of the wing in chickens and exotic avian species that have similar wing anatomy.
authors.affiliation: Faculdade de Agronomia e Medicina Veterinaria, Universidade de Brasilia, Brasilia, Brazil. julianaf@uga.edu
authors.forename: Juliana P
authors.initials: JP
authors.lastname: Figueiredo
authors.forename: Mariângela L
authors.initials: ML
authors.lastname: Cruz
authors.forename: Guilherme M
authors.initials: GM
authors.lastname: Mendes
authors.forename: Rodrigo L
authors.initials: RL
authors.lastname: Marucio
authors.forename: Carolina H
authors.initials: CH
authors.lastname: Riccó
authors.forename: Daniela
authors.initials: D
authors.lastname: Campagnol
mesh_terms: D000759:Adjuvants, Anesthesia / Q000008:administration & dosage / Q000494:pharmacology; D000698:Analgesia / Q000662:veterinary; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001917:Brachial Plexus / Q000187:drug effects*; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology*; D002645:Chickens; D005260:Female; D008874:Midazolam / Q000008:administration & dosage / Q000494:pharmacology*; D009407:Nerve Block / Q000379:methods / Q000662:veterinary*
chemical_list: D000759:Adjuvants, Anesthesia; D000701:Analgesics, Opioid; D002077:Butorphanol; D008874:Midazolam