title: Comparison of Nerve Stimulation-guided Axillary Brachial Plexus Block, Single Injection versus Four Injections: A Prospective Randomized Double-blind Study.
abstract: BACKGROUND
  A variety of techniques have been described for the axillary block using nerve stimulator, either with single injection, two, three, or four separate injections. Identification of all the four nerves is more difficult and time-consuming than other methods.
  
  
  OBJECTIVE
  Aim of the present study is to compare success rate, onset, and duration of sensory and motor anesthesia of axillary block using nerve stimulator, either with single injection after identification of any one of the four nerves or four separate injections following identification of each of nerve.
  
  
  METHODS
  Prospective, randomized, double-blind study. Patients undergoing forearm and hand surgeries under axillary block.
  
  
  METHODS
  One hundred patients, aged 18-75 years, were randomly allocated into two groups of 50 each. Axillary block was performed under the guidance of nerve stimulator with a mixture of 18 ml of 1.5% lignocaine and 18 ml of 0.5% bupivacaine. In the first group (n= 50), all 36 ml of local anesthetic was injected after the identification of motor response to any one of the nerves and in Group 2, all the four nerves were identified by the motor response, and 9 ml of local anesthetic was injected at each of the nerves. The success rate of the block, onset, and duration of sensory and motor block was assessed.
  
  
  METHODS
  Categorical variables were compared using the Chi-square test, and continuous variables were compared using independentt-test.
  
  
  RESULTS
  The success rate of the block with four injection technique was higher compared to single-injection technique (84% vs. 56%,P= 0.02). Four injection groups had a faster onset of sensory and motor block and prolonged duration of analgesia compared to single-injection group (P< 0.001). There were no significant differences in the incidence of accidental arterial puncture and hemodynamic parameter between the groups.
  
  
  CONCLUSIONS
  Identification of all the four nerves produced higher success rate and better quality of the block when compared to single-injection technique.
authors.affiliation: Department of Anaesthesiology, SDMCMS and H, Dharwad, Karnataka, India.
authors.forename: Santoshi V
authors.initials: SV
authors.lastname: Badiger
authors.affiliation: Department of Anaesthesiology, SDMCMS and H, Dharwad, Karnataka, India.
authors.forename: Sameer N
authors.initials: SN
authors.lastname: Desai
keywords: Anesthesia technique; brachial plexus block; nerve block; regional anesthesia