title: A randomized, double-blind trial of pre-emptive local anesthesia in day-case knee arthroscopy.
abstract: OBJECTIVE
  The study goal was to assess the efficacy of pre-emptive analgesia in a clinical setting.
  
  
  METHODS
  A block randomized, double-blind design was used.
  
  
  METHODS
  Subjects were 40 patients undergoing day-case arthroscopy of the knee. The trial group received a prophylactic injection of bupivacaine with adrenaline. After surgery, a placebo injection was given. The postsurgical injection group received identical injections in reverse order. There was no difference in the mean dose of propofol used to maintain general anesthesia between groups: 15 mg/kg/h (standard deviation [SD] = 2.85) trial versus 14.6 mg/kg/h (SD = 1.96) postsurgical injection (95% confidence interval [CI] = -1.14 to 1.94).
  
  
  RESULTS
  Although no statistically significant difference was observed in postoperative pain scores at 15, 30, or 60 minutes, there was a trend for the trial group to require less analgesia in recovery (chi2 = 9.74; P =.1).
  
  
  CONCLUSIONS
  Prophylactic local anesthesia confers no statistically significant reduction in pain scores or perioperative general anesthetic requirements as compared with postoperative administration. The pre-emptive effect in clinical practice may be less dramatic than that observed in more controlled animal models. Further studies are required to investigate the magnitude of the pre-emptive effect in clinical practice.
authors.affiliation: Department of Trauma and Orthopaedic Surgery, Weston General Hospital, Weston-Super-Mare, North Somerset, England. dan@fagankav.freeserve.co.uk
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Fagan
authors.forename: William
authors.initials: W
authors.lastname: Martin
authors.forename: Alison
authors.initials: A
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D001182:Arthroscopy / Q000379:methods*; D002045:Bupivacaine / Q000008:administration & dosage / Q000627:therapeutic use; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004837:Epinephrine / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D007717:Knee / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000517:prevention & control*; D011182:Postoperative Care / Q000379:methods; D011300:Preoperative Care / Q000379:methods
chemical_list: D004338:Drug Combinations; D002045:Bupivacaine; D004837:Epinephrine