title: Effect of extradurally administered morphine on postoperative analgesia in dogs undergoing surgery for thoracolumbar intervertebral disk extrusion.
abstract: OBJECTIVE
  To investigate the effect of intraoperative extradural morphine administration on postoperative analgesia in dogs undergoing thoracolumbar spinal surgery to treat disk extrusion.
  
  
  METHODS
  Prospective clinical trial.
  
  
  METHODS
  26 client-owned dogs undergoing thoracolumbar spinal surgery.
  
  
  METHODS
  Animals were randomly allocated to receive morphine (0.1 mg/kg [0.045 mg/lb], extradurally) or no treatment (control group). Following preanesthetic medication with methadone (0.25 mg/kg [0.11 mg/lb], IM), anesthesia was induced with propofol and maintained with isoflurane or sevoflurane in oxygen. Lidocaine and fentanyl were administered during surgery in both groups at fixed rates. In the morphine administration group, morphine was splashed over the dura mater immediately prior to wound closure. Postoperative analgesia was assessed for 48 hours by assessors unaware of group allocation, and methadone was administered as rescue analgesic. Demographic characteristics, urinary output, days of hospitalization, and perioperative use of analgesics were compared via a Mann-Whitney U test.
  
  
  RESULTS
  Demographic data were similar between groups. In the morphine administration group, 2 of 13 dogs required postoperative methadone, and in the control group, methadone was administered to 11 of 13 dogs. The total number of doses of methadone administered in the 48 hours after surgery was 28 in the control group and 3 in the morphine administration group. No adverse effects were recorded in any group.
  
  
  CONCLUSIONS
  Intraoperative extradural morphine administration was effective in reducing postoperative analgesic requirement. Dogs undergoing thoracolumbar spinal surgery benefited from topical administration of preservative-free morphine administered directly on the dura mater as part of analgesic management.
authors.affiliation: Dick White Referrals Veterinary Specialist Centre, Newmarket, Suffolk, England.
authors.forename: Francesco
authors.initials: F
authors.lastname: Aprea
authors.forename: Giunio B
authors.initials: GB
authors.lastname: Cherubini
authors.forename: Viktor
authors.initials: V
authors.lastname: Palus
authors.forename: Enzo
authors.initials: E
authors.lastname: Vettorato
authors.forename: Federico
authors.initials: F
authors.lastname: Corletto
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D004283:Dog Diseases / Q000188:drug therapy / Q000601:surgery*; D004285:Dogs; D004334:Drug Administration Schedule; D007268:Injections, Epidural; D007405:Intervertebral Disc Displacement / Q000601:surgery / Q000662:veterinary*; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use*; D010149:Postoperative Pain / Q000517:prevention & control / Q000662:veterinary*; D059035:Perioperative Period
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine