title: Intra-operative remifentanil might influence pain levels in the immediate post-operative period after major abdominal surgery.
abstract: BACKGROUND
  Remifentanil, a widely used analgesic agent in anaesthesia, has a rapid onset and short duration of action. In clinical settings, this requires an appropriate pain strategy to prevent unacceptable pain in the post-operative period. The aim of this study was to investigate whether remifentanil had any impact on post-operative pain and opioid consumption after major abdominal surgery.
  
  
  METHODS
  Fifty patients undergoing major abdominal surgery were randomized to receive either remifentanil 0.4 microg/kg/min or placebo intra-operatively, in addition to basic combined general and epidural anaesthesia, in this double-blind study. Patients received patient-controlled analgesia with morphine for 24 h post-operatively. Morphine consumption, assessment of pain at rest and during coughing, side-effects and levels of sensory block were recorded during the first 24 h post-operatively.
  
  
  RESULTS
  Twenty-one patients receiving remifentanil and 18 patients receiving placebo completed the study. The median visual analogue scale (VAS) score at rest from 0 to 2 h was significantly increased in the remifentanil group [40 mm (27-61 mm)] vs. placebo [13 mm (3-35 mm)] (P < 0.05). No significant differences in morphine consumption, VAS score during coughing or adverse effects were observed between the groups.
  
  
  CONCLUSIONS
  The results are weak and difficult to interpret. They could indicate that a high dose of remifentanil added to otherwise sufficient combined general and epidural anaesthesia may induce opioid-induced hyperalgesia and/or clinically acute opioid tolerance after major abdominal surgery; however, as no significant differences could be observed between the groups after 2 h post-operatively, the clinical relevance of these observations is questionable.
authors.affiliation: Department of Anaesthesiology, Herlev University Hospital, Herlev, Denmark.
authors.forename: E G
authors.initials: EG
authors.lastname: Hansen
authors.forename: T H
authors.initials: TH
authors.lastname: Duedahl
authors.forename: J
authors.initials: J
authors.lastname: Rømsing
authors.forename: K-L
authors.initials: KL
authors.lastname: Hilsted
authors.forename: J B
authors.initials: JB
authors.lastname: Dahl
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use*; D000771:Anesthesia, Intravenous; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control* / Q000523:psychology; D010880:Piperidines / Q000008:administration & dosage / Q000627:therapeutic use*; D011156:Population Density; D000077208:Remifentanil
chemical_list: D000701:Analgesics, Opioid; D010880:Piperidines; D009020:Morphine; D000077208:Remifentanil