title: Intra- and postoperative low-dose ketamine for adolescent idiopathic scoliosis surgery: a randomized controlled trial.
abstract: BACKGROUND
  In this randomized controlled trial, we examined whether intra- and postoperative infusion of low-dose ketamine decreased postoperative morphine requirement and morphine-related adverse effects as nausea and vomiting after scoliosis surgery.
  
  
  METHODS
  After IRB approval and informed consent, 36 patients, aged 10-19 years, undergoing posterior correction surgery for adolescent idiopathic scoliosis, were randomly allocated into two groups: intra- and postoperative ketamine infusion at a rate of 2 μg/kg/min until 48 h after surgery (ketamine group, n = 17) or infusion of an equal volume of saline (placebo group, n = 19). All patients were administered total intravenous anesthesia with propofol and remifentanil during surgery and intravenous morphine using a patient-controlled analgesia device after surgery. The primary outcome was cumulative morphine consumption in the initial 48 h after surgery. Pain scores (Numerical Rating Scale, NRS, 0-10), sedation scales, incidence of postoperative nausea and vomiting (PONV), and antiemetic consumption were recorded by nurses blinded to the study protocol for 48 h after surgery.
  
  
  RESULTS
  Patient characteristics did not differ between the two groups. Cumulative morphine consumption for 48 h after surgery was significantly lower in the ketamine group compared to the placebo group (0.89 ± 0.08 mg/kg vs. 1.16 ± 0.07 mg/kg, 95% confidence interval for difference between the means, 0.03-0.48 mg/kg, P = 0.019). NRS pain, sedation scales, and incidence of PONV did not differ between the two groups. Antiemetic consumption was significantly smaller in ketamine group.
  
  
  CONCLUSIONS
  Intra- and postoperative infusion of low-dose ketamine reduced cumulative morphine consumption and antiemetic requirement for 48 h after surgery.
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Minoshima
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kosugi
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Nishimura
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ihara
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Seki
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Katori
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Hashiguchi
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Morisaki
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D009020:Morphine / Q000008:administration & dosage; D010149:Postoperative Pain / Q000517:prevention & control; D020250:Postoperative Nausea and Vomiting / Q000517:prevention & control; D012600:Scoliosis / Q000601:surgery*; D055815:Young Adult
chemical_list: D007649:Ketamine; D009020:Morphine