title: Do the Concentration and Volume of Local Anesthetics Affect the Onset and Success of Infraclavicular Anesthesia?
abstract: BACKGROUND
  Although local anesthesia is a suitable method for upper limb surgeries, there is debate regarding the effects of appropriate dosing.
  
  
  OBJECTIVE
  In the current study, we investigated the effects of the concentration and volume of a local anesthetic on the beginning and quality of anesthesia during upper limb orthopedic surgeries.
  
  
  METHODS
  This double-blinded, randomized, clinical trial was conducted on 60 patients aged between 18 and 85 years candidated for upper limb orthopedic operations. The patients were equally and randomly distributed into two groups (n = 30). Under ultrasound imaging guidance, the first group received 7 mL of 2% lidocaine and the second group 10 mL of 1.3% lidocaine into the brachial plexus cords. The onset of block and the level of sensory and motor block were documented for each nerve territory.
  
  
  RESULTS
  The onset of sensory and motor block was significantly shorter in the 1.3% lidocaine group than in the 2% lidocaine group (P ≤ 0.05). The success rate of sensory and motor block was not different. The quality (completeness) of sensory block for the musculocutaneous nerve and that of motor block for the radial nerve were significantly better in the 1.3% lidocaine group than in the 2% lidocaine group.
  
  
  CONCLUSIONS
  The volume of the injected anesthetic accelerated the onset of sensory and motor block without affecting the rate of success in our patients.
authors.affiliation: Anesthesiology and Critical Care Department, Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Faramarz
authors.initials: F
authors.lastname: Mosaffa
authors.affiliation: Anesthesiology and Critical Care Department, Labbafinejad Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Gharaei
authors.affiliation: Orthopedic Department, Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Qoreishi
authors.affiliation: Anesthesiology and Critical Care Department, Mofid Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Sajjad
authors.initials: S
authors.lastname: Razavi
authors.affiliation: Anesthesiology and Critical Care Department, Loghmane Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Safari
authors.affiliation: Anesthesiology Research Center, Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Fathi
authors.affiliation: Anesthesiology and Critical Care Department, Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Mohseni
authors.affiliation: Anesthesiology and Critical Care Department, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hedayatollah
authors.initials: H
authors.lastname: Elyasi
authors.affiliation: Anesthesiology and Critical Care Department, Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Hosseini
keywords: Anesthesia, Local; Anesthetics; Brachial Plexus; Lidocaine; Nerve Block