title: Dexmedetomidine added to an opioid-based analgesic regimen for the prevention of postoperative nausea and vomiting in highly susceptible patients: A randomised controlled trial.
abstract: BACKGROUND
  Dexmedetomidine, an α2 adrenergic receptor agonist, has analgesic, sedative and sympatholytic properties, with a lack of respiratory depression. It is licensed only for intensive care sedation.
  
  
  OBJECTIVE
  The objective of this study is to investigate whether intravenous (i.v.) patient-controlled analgesia (PCA) with dexmedetomidine added to a fentanyl-based drug mixture could reduce postoperative nausea and vomiting (PONV) in highly susceptible patients undergoing lumbar spinal surgery.
  
  
  METHODS
  A randomised, double-blinded study.
  
  
  METHODS
  At a tertiary university hospital between September 2012 and September 2013.
  
  
  METHODS
  One hundred and eight patients undergoing level 1 or 2 posterior lumbar spinal fusion who had at least three risk factors for PONV (female, nonsmoker, use of postoperative opioids) were randomised into two groups. Three patients were excluded from analysis and 105 patients completed the study.
  
  
  METHODS
  Patients received either dexmedetomidine 0.5 μg kg⁻¹ i.v. (dexmedetomidine group) or 0.9% normal saline (control group) 30 min before the completion of surgery followed by fentanyl 0.5 μg kg⁻¹ and 4 mg ondansetron. Postoperatively, the PCA (fentanyl 10 μg kg⁻¹ with 120 mg ketorolac, with or without dexmedetomidine 10 μg kg⁻¹ made up to a total volume of 100 ml) was programmed to deliver 1 ml bolus (lockout 15 min) with a continuous background infusion of 2 ml h⁻¹. The PCA was used for the first 48 h postoperatively.
  
  
  METHODS
  The incidence and severity of PONV, cumulative dose of PCA fentanyl consumed and pain scores were assessed for 48 h.
  
  
  RESULTS
  The dexmedetomidine group experienced less nausea during the time interval 1 to 3 h postoperatively compared with the control group [odds ratio (OR) 0.32; 95% confidence interval (CI) 0.13 to 0.77; P = 0.019]. The intensity of nausea between the groups during the first 48 h was comparable, but the dexmedetomidine group had a lower incidence of moderate to severe nausea (OR 0.28; 95% CI 0.12 to 0.67; P < 0.003). Pain scores were not significantly different between the groups, but patients in the dexmedetomidine group required less fentanyl and less rescue analgesia in the first 12 h. Compared with the control group, patients in the dexmedetomidine group experienced almost twice as many episodes of hypotension and bradycardia, but this failed to reach statistical significance.
  
  
  CONCLUSIONS
  Adding dexmedetomidine to a fentanyl-based PCA drug mixture reduces the frequency and severity of acute postoperative nausea in highly susceptible patients.
  
  
  BACKGROUND
  Clinicaltrials.gov identifier: NCT01840254.
authors.affiliation: From the Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University Health System, Seoul, South Korea.
authors.forename: Young
authors.initials: Y
authors.lastname: Song
authors.forename: Jae-Kwang
authors.initials: JK
authors.lastname: Shim
authors.forename: Jong-Wook
authors.initials: JW
authors.lastname: Song
authors.forename: Eui-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Young-Lan
authors.initials: YL
authors.lastname: Kwak
mesh_terms: D061605:Administration, Intravenous; 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; D016009:Chi-Square Distribution; D020927:Dexmedetomidine / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage* / Q000009:adverse effects; D006785:Hospitals, University; D006801:Humans; D016014:Linear Models; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D019637:Orthopedic Procedures / Q000009:adverse effects; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control*; D056910:Republic of Korea; D012307:Risk Factors; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D020927:Dexmedetomidine; D005283:Fentanyl