title: Effect of ketamine as an adjunct to intravenous patient-controlled analgesia, in patients at high risk of postoperative nausea and vomiting undergoing lumbar spinal surgery.
abstract: BACKGROUND
  We evaluated the effect of ketamine as an adjunct to a fentanyl-based i.v. patient-controlled analgesia (IV-PCA) on postoperative nausea and vomiting (PONV) in patients at high risk of PONV undergoing lumbar spinal surgery.
  
  
  METHODS
  Fifty non-smoking female patients were evenly randomized to either the control or ketamine group. According to randomization, patients received either ketamine 0.3 mg kg(-1) i.v. or normal saline after anaesthetic induction with fentanyl-based IV-PCA either with or without ketamine mixture (3 mg kg(-1) in 180 ml). The incidence and severity of PONV, volume of IV-PCA consumed, and pain intensity were assessed in the postanaesthesia care unit, and at postoperative 6, 12, 24, 36, and 48 h.
  
  
  RESULTS
  The overall incidence of PONV during the first 48 h after surgery was similar between the two groups (68 vs 56%, ketamine and control group, P=0.382). The total dose of fentanyl used during the first 48 h after operation was lower in the ketamine group than in the control group [mean (SD), 773 (202) μg vs 957 (308) μg, P=0.035]. The intensity of nausea (11-point verbal numerical rating scale) was higher in the ketamine group during the first 6 h after operation [median (interquartile range), 6 (3-7) vs 2 (1.5-3.5), P=0.039], postoperative 12-24 h [5 (4-7) vs 2 (1-3), P=0.014], and postoperative 36-48 h [5 (4-7) vs 2 (1-3), P=0.036]. Pain intensities were similar between the groups.
  
  
  CONCLUSIONS
  Ketamine did not reduce the incidence of PONV and exerted a negative influence on the severity of nausea. It was, however, able to reduce postoperative fentanyl consumption in patients at high-risk of PONV.
authors.affiliation: Department of Anaesthesiology and Pain Medicine and.
authors.forename: J W
authors.initials: JW
authors.lastname: Song
authors.forename: J K
authors.initials: JK
authors.lastname: Shim
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.forename: S Y
authors.initials: SY
authors.lastname: Yang
authors.forename: S J
authors.initials: SJ
authors.lastname: Park
authors.forename: Y L
authors.initials: YL
authors.lastname: Kwak
mesh_terms: D000328:Adult; D000368:Aged; D016058:Analgesia, Patient-Controlled / Q000009:adverse effects* / Q000379:methods; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000009:adverse effects*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage / Q000009:adverse effects*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000517:prevention & control; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced* / Q000517:prevention & control; D012720:Severity of Illness Index; D013123:Spinal Fusion
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D007649:Ketamine; D005283:Fentanyl
keywords: analgesia, patient-controlled; ketamine; postoperative nausea and vomiting