title: Intraoperative tramadol reduces shivering but not pain after remifentanil-isoflurane general anaesthesia. A placebo-controlled, double-blind trial.
abstract: OBJECTIVE
  Postoperative shivering and pain are frequent problems in patients recovering from anaesthesia with particularly high incidences being observed after remifentanil-isoflurane-based general anaesthesia. The opioid tramadol is generally effective in preventing shivering and treating pain, but its effects are not characterized after remifentanil-based general anaesthesia. This randomized, placebo-controlled, double-blind study evaluated the effects of intraoperative intravenous tramadol on postoperative shivering and pain after remifentanil-based general anaesthesia.
  
  
  METHODS
  After Ethics Committee approval, 60 patients scheduled for lumbar disc surgery were included. Surgery was performed under general anaesthesia (remifentanil, isoflurane). Patients were randomly assigned to receive 2 mg kg(-1) tramadol in 30 mL 0.9% saline infused intravenously (n = 30) or 30 mL saline (n = 30) 45-30 min before skin closure. The following parameters were assessed every 10 min for 2 h: shivering, pain, postoperative nausea and vomiting, sedation, heart rate, non-invasive blood pressure and peripheral oxygen saturation. The primary outcome variable was the incidence of shivering during the first 2 postoperative hours. Secondary variables were: shivering intensity, pain, postoperative nausea and vomiting, sedation, heart rate, non-invasive blood pressure and peripheral oxygen saturation.
  
  
  RESULTS
  Shivering was less frequent in patients treated with tramadol (20% vs. 70%, P = 0.0009) and was of lower intensity (severe shivering: 10% vs. 46.7%, P = 0.003). Pain scores were similar between the groups and all other secondary outcome variables failed to reveal significant differences.
  
  
  CONCLUSIONS
  Compared with placebo, intraoperative intravenous administration of 2 mg kg(-1) tramadol reduces the incidence and extent of postoperative shivering without alterations in pain perception after lumbar disc surgery under remifentanil-isoflurane-based general anaesthesia.
authors.affiliation: Johannes Gutenberg-University, Department of Anaesthesiology, Mainz, Germany. heid@uni-mainz.de
authors.forename: F
authors.initials: F
authors.lastname: Heid
authors.forename: U
authors.initials: U
authors.lastname: Grimm
authors.forename: W
authors.initials: W
authors.lastname: Roth
authors.forename: T
authors.initials: T
authors.lastname: Piepho
authors.forename: T
authors.initials: T
authors.lastname: Kerz
authors.forename: J
authors.initials: J
authors.lastname: Jage
mesh_terms: D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000601:surgery; D007430:Intraoperative Care; D007530:Isoflurane; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control*; D010880:Piperidines; D020250:Postoperative Nausea and Vomiting; D000077208:Remifentanil; D012768:Shivering / Q000187:drug effects*; D014147:Tramadol / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D010880:Piperidines; D014147:Tramadol; D007530:Isoflurane; D000077208:Remifentanil