title: The addition of a tramadol infusion to morphine patient-controlled analgesia after abdominal surgery: a double-blinded, placebo-controlled randomized trial.
abstract: In this double-blinded, randomized controlled trial, we tested whether the addition of tramadol to morphine for patient-controlled analgesia (PCA) resulted in improved analgesia efficacy and smaller morphine requirements compared with morphine PCA alone after abdominal surgery in adults. Sixty-nine patients were randomly allocated into two groups, each receiving morphine 1 mg/mL via PCA after surgery. The tramadol group received an intraoperative initial loading dose of tramadol (1 mg/kg) and a postoperative infusion of tramadol at 0.2 mg. kg(-1). h(-1). The control group received an intraoperative equivalent volume of normal saline and a postoperative saline infusion. Postoperatively, tramadol was associated with improved subjective analgesic efficacy (P = 0.031) and there was significantly less PCA morphine use in the tramadol group (P = 0.023). No differences between the groups were found with regard to nausea, antiemetic use, sedation, or quality of recovery (all P > 0.05). We conclude that a tramadol infusion combined with PCA morphine improves analgesia and reduces morphine requirements after abdominal surgery compared with morphine PCA alone.
  
  
  CONCLUSIONS
  In this study, we determined whether adding a second pain-killing drug, tramadol, could improve pain relief after major surgery in patients receiving morphine patient-controlled analgesia. We found that patients receiving tramadol had significantly better opinions of their pain relief and used significantly less morphine with no increase in side effects.
authors.affiliation: Department of Anaesthesia, Frankston Hospital, Victoria, Australia. awebb@phcn.vic.gov.au
authors.forename: Ashley R
authors.initials: AR
authors.lastname: Webb
authors.forename: Samuel
authors.initials: S
authors.lastname: Leong
authors.forename: Paul S
authors.initials: PS
authors.lastname: Myles
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Burn
mesh_terms: D000005:Abdomen / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D014147:Tramadol / Q000008:administration & dosage*
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol; D009020:Morphine