title: I.V. and perineural dexamethasone are equivalent in increasing the analgesic duration of a single-shot interscalene block with ropivacaine for shoulder surgery: a prospective, randomized, placebo-controlled study.
abstract: BACKGROUND
  Interscalene brachial plexus block (ISB) provides excellent, but time-limited analgesia. Dexamethasone added to local anaesthetics prolongs the duration of a single-shot ISB. However, systemic glucocorticoids also improve postoperative analgesia. The hypothesis was tested that perineural and i.v. dexamethasone would have an equivalent effect on prolonging analgesic duration of an ISB.
  
  
  METHODS
  We performed a prospective, double blind, randomized, placebo-controlled study. Patients presenting for arthroscopic shoulder surgery with an ISB were randomized into three groups: ropivacaine 0.5% (R); ropivacaine 0.5% and dexamethasone 10 mg (RD); and ropivacaine 0.5% with i.v. dexamethasone 10 mg (RDiv). The primary outcome was the duration of analgesia, defined as the time between performance of the block and the first analgesic request. Standard hypothesis tests (t-test, Mann-Whitney U-test) were used to compare treatment groups. The primary outcome was analysed by Kaplan-Meier survival analysis with a log-rank test and Cox's proportional hazards regression.
  
  
  RESULTS
  One hundred and fifty patients were included after obtaining ethical committee approval and patient informed consent. The median time of a sensory block was equivalent for perineural and i.v. dexamethasone: 1405 min (IQR 1015-1710) and 1275 min (IQR 1095-2035) for RD and RDiv, respectively. There was a significant difference between the ropivacaine group: 757 min (IQR 635-910) and the dexamethasone groups (P<0.0001).
  
  
  CONCLUSIONS
  I.V. dexamethasone is equivalent to perineural dexamethasone in prolonging the analgesic duration of a single-shot ISB with ropivacaine. As dexamethasone is not licensed for perineural use, clinicians should consider i.v. administration of dexamethasone to achieve an increased duration of ISB.
authors.affiliation: Department of Anesthesiology, AZ Groeninge, Loofstraat 43, 8500 Kortrijk, Belgium. matthias.desmet@azgroeninge.be
authors.forename: M
authors.initials: M
authors.lastname: Desmet
authors.forename: H
authors.initials: H
authors.lastname: Braems
authors.forename: M
authors.initials: M
authors.lastname: Reynvoet
authors.forename: S
authors.initials: S
authors.lastname: Plasschaert
authors.forename: J
authors.initials: J
authors.lastname: Van Cauwelaert
authors.forename: H
authors.initials: H
authors.lastname: Pottel
authors.forename: S
authors.initials: S
authors.lastname: Carlier
authors.forename: C
authors.initials: C
authors.lastname: Missant
authors.forename: M
authors.initials: M
authors.lastname: Van de Velde
mesh_terms: D000759:Adjuvants, Anesthesia / Q000494:pharmacology; D061605:Administration, Intravenous; D000577:Amides; D000779:Anesthetics, Local; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D000077212:Ropivacaine; D012782:Shoulder / Q000601:surgery*; D013997:Time Factors
chemical_list: D000759:Adjuvants, Anesthesia; D000577:Amides; D000779:Anesthetics, Local; D005938:Glucocorticoids; D000077212:Ropivacaine; D003907:Dexamethasone
keywords: anaesthetic techniques, i.v. regional; anaesthetic techniques, regional, brachial plexus; anaesthetics local, ropivacaine; analgesia, postoperative; analgesics anti-inflammatory, steroid