title: Controlled-release oxycodone is better tolerated than intravenous tramadol/metamizol for postoperative analgesia after retinal-surgery.
abstract: OBJECTIVE
  We assessed the clinical efficacy and tolerance of controlled-release oxycodone (CRO), comparing it with intravenous tramadol/metamizol combination in this prospective, randomised, double-blind study of 35 ASA physical status I-III patients undergoing retinal-surgery.
  
  
  METHODS
  General anaesthesia using remifentanil and propofol was performed for surgery. On arrival in the recovery room patients were randomly allocated to two groups. The controlled-release oxycodone group (CRO Group) received 10 mg CRO. 12 h after the initial dose another 10 mg CRO were administered. Simultaneously with the initial CRO dose, and every 4 h up to 24 h postoperatively, the CRO Group received intravenous isotonic saline infusion. On arrival in the recovery room the tramadol/metamizol group (TM Group) received a placebo tablet, and 12 h later a second placebo. Simultaneously 100 mg tramadol combined with 1 g metamizol were administered intravenously every 4 h until 24 h postoperatively. All patients had access to intravenous opioid rescue medication.
  
  
  RESULTS
  The AUC for quality of analgesia was significantly higher in the CRO Group than in the TM Group (p = 0.0023). Patient rated quality of analgesia significantly higher in the CRO Group than in the TM Group 8 h (p = 0.048), 16 h (p = 0.009) and 24 h (p = 0.001) postoperatively. There was no statistical difference in AUC for pain scores between groups (p = 0.205). The CRO Group experienced significantly less nausea than the TM Group (p = 0.012). Six patients in the TM Group in contrast to none in the CRO Group interrupted the study before finishing the study protocol (p = 0.022).
  
  
  CONCLUSIONS
  We conclude that CRO administered twice in the first 24 h postoperatively is superior to intravenous tramadol/metamizol for postoperative analgesia after retinal surgery, with fewer adverse events and greater patient satisfaction.
authors.affiliation: Department of Anaesthesiology, University of Cologne, Cologne, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kaufmann
authors.forename: S
authors.initials: S
authors.lastname: Yesiloglu
authors.forename: B
authors.initials: B
authors.lastname: Patermann
authors.forename: J
authors.initials: J
authors.lastname: Krombach
authors.forename: P
authors.initials: P
authors.lastname: Kiencke
authors.forename: S
authors.initials: S
authors.lastname: Kampe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D004177:Dipyrone / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D010098:Oxycodone / Q000627:therapeutic use*; D010149:Postoperative Pain / Q000188:drug therapy*; D011446:Prospective Studies; D012164:Retinal Diseases / Q000601:surgery*; D014147:Tramadol / Q000627:therapeutic use*
chemical_list: D000701:Analgesics, Opioid; D000894:Anti-Inflammatory Agents, Non-Steroidal; D003692:Delayed-Action Preparations; D014147:Tramadol; D004177:Dipyrone; D010098:Oxycodone