title: [A comparative study on the postoperative analgesic efficacy of 20, 30, or 40 mL of ropivacaine in posterior brachial plexus block.].
abstract: OBJECTIVE
  Arthroscopic surgeries of the shoulder are accompanied by severe postoperative pain. Among the analgesic techniques, brachial plexus block offers the best results. The objective of this study was to determine which volume of local anesthetic in the posterior brachial plexus block offers more adequate analgesia for those procedures.
  
  
  METHODS
  Ninety patients undergoing posterior brachial plexus block were randomly divided in three groups of 30 patients: Group 1 volume of 20 mL; Groups 2 volume of 30 mL; Group 3 volume of 40 mL. In all groups 0.375% ropivacaine was the anesthetic used. The blockade was evaluated by testing thermal sensitivity using a cotton ball embedded in alcohol, while postoperative pain was evaluated according to a verbal numeric scale (VNS) in the first 24 hours.
  
  
  RESULTS
  Postoperative analgesia was similar in all three groups according to the parameters evaluated: VNS of moderate pain, length of time until the first complaint of pain, and consumption of opioids. Consumption of non-opioid analgesics was greater in the 20 mL group after the 12th postoperative hour. In the 30 and 40 mL groups, the extension of the blockade was significantly greater.
  
  
  CONCLUSIONS
  This study demonstrated that posterior brachial block promotes effective analgesia for surgeries of the shoulder. The three different volumes studied promoted similar analgesia. The greater extension of the blockade with larger doses did not translate into better analgesia.
authors.affiliation: Hospital Lifecenter.
authors.forename: Marcos Guilherme Cunha
authors.initials: MG
authors.lastname: Cruvinel
authors.forename: Carlos Henrique Viana de
authors.initials: CH
authors.lastname: Castro
authors.forename: Yerkes Pereira
authors.initials: YP
authors.lastname: Silva
authors.forename: Gustavo Prosperi
authors.initials: GP
authors.lastname: Bicalho
authors.forename: Flávio de Oliveira
authors.initials: Fde O
authors.lastname: França
authors.forename: Flávio
authors.initials: F
authors.lastname: Lago