title: Perineural but not systemic low-dose dexamethasone prolongs the duration of interscalene block with ropivacaine: a prospective randomized trial.
abstract: OBJECTIVE
  To determine the effects of intravenous and perineural dexamethasone on the duration of interscalene brachial plexus block (ISB) with ropivacaine in patients undergoing arthroscopic shoulder surgery.
  
  
  METHODS
  In this prospective, randomized, placebo-controlled trial, patients presenting for arthroscopic shoulder surgery with an ISB were randomized to receive ropivacaine 0.75% (group C), ropivacaine 0.75% plus perineural dexamethasone 4 mg (group Dperi), or ropivacaine 0.75% plus intravenous dexamethasone 4 mg (group Div). The primary outcome was the duration of analgesia, defined as the time between performance of the block and the first request for analgesic.
  
  
  RESULTS
  Thirty-nine patients were randomized. The median times of sensory block in groups C, Dperi, and Div were 11.2 hours (interquartile range [IQR] 8.0-15.0 hours), 18.0 hours (IQR 14.5-19.0 hours), and 14.0 hours (IQR 12.7-15.1 hours), respectively. Significant differences were observed between groups Dperi and C (P=0.001). Kaplan-Meier analysis for the first analgesic request showed significant differences between groups Dperi and C (P=0.005) and between groups Dperi and Div (P=0.008), but not between groups C and Div.
  
  
  CONCLUSIONS
  Perineural but not intravenous administration of 4 mg of dexamethasone significantly prolongs the duration of effective postoperative analgesia resulting from a single-shot ISB with ropivacaine 0.75%.
authors.affiliation: Department of Anesthesiology, Tokushima University Hospital, Tokushima, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kawanishi
authors.affiliation: Division of Anesthesiology, Tokushima Red Cross Hospital, Komatsushima, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Division of Anesthesiology, Tokushima Red Cross Hospital, Komatsushima, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tobetto
authors.affiliation: Division of Anesthesiology, Tokushima Red Cross Hospital, Komatsushima, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Nomura
authors.affiliation: Division of Anesthesiology, Tokushima Red Cross Hospital, Komatsushima, Japan.
authors.forename: Michihisa
authors.initials: M
authors.lastname: Kato
authors.affiliation: Division of Anesthesiology, Tokushima Red Cross Hospital, Komatsushima, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Go
authors.affiliation: Department of Anesthesiology, Institute of Health Bioscience, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Yasuo M
authors.initials: YM
authors.lastname: Tsutsumi
authors.affiliation: Department of Anesthesiology, Institute of Health Bioscience, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Division of Orthopedics, Tokushima Red Cross Hospital, Komatsushima, Japan.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Takeda
keywords: dexamethasone; interscalene nerve block; perineural; postoperative pain; ropivacaine