title: [A factorial trial of six interventions for the prevention of postoperative nausea and vomiting].
abstract: BACKGROUND
  Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown.
  
  
  METHODS
  In a randomized, controlled trial of factorial design, 5,199 patients at high risk for postoperative nausea and vomiting were randomly assigned to 1 of 64 possible combinations of 6 prophylactic interventions: 1) 4 mg of ondansetron or no ondansetron; 2) 4 mg of dexamethasone or no dexamethasone; 3) 1.25 mg of droperidol or no droperidol; 4) propofol or a volatile anesthetic; 5) nitrogen or nitrous oxide; 6) remifentanil or fentanyl. The primary aim parameter was nausea and vomiting within 24 h after surgery, which was evaluated blindly.
  
  
  RESULTS
  Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26%, propofol reduced the risk by 19%, and nitrogen by 12%. The risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics alone. All the interventions acted independently of each other and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. However, absolute risk reduction was a critical function of patients' baseline risk.
  
  
  CONCLUSIONS
  Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.
authors.affiliation: Klinik und Poliklinik für Anaesthesiologie, Julius-Maximilians Universität, Würzburg. apfel@ponv.org
authors.forename: C C
authors.initials: CC
authors.lastname: Apfel
authors.forename: A
authors.initials: A
authors.lastname: Bacher
authors.forename: A
authors.initials: A
authors.lastname: Biedler
authors.forename: K
authors.initials: K
authors.lastname: Danner
authors.forename: O
authors.initials: O
authors.lastname: Danzeisen
authors.forename: L H J
authors.initials: LH
authors.lastname: Eberhart
authors.forename: H
authors.initials: H
authors.lastname: Forst
authors.forename: G
authors.initials: G
authors.lastname: Fritz
authors.forename: M
authors.initials: M
authors.lastname: Hergert
authors.forename: G
authors.initials: G
authors.lastname: Frings
authors.forename: A
authors.initials: A
authors.lastname: Goebel
authors.forename: H-B
authors.initials: HB
authors.lastname: Hopf
authors.forename: H
authors.initials: H
authors.lastname: Kerger
authors.forename: P
authors.initials: P
authors.lastname: Kranke
authors.forename: M
authors.initials: M
authors.lastname: Lange
authors.forename: F
authors.initials: F
authors.lastname: Mertzlufft
authors.forename: J
authors.initials: J
authors.lastname: Motsch
authors.forename: A
authors.initials: A
authors.lastname: Paura
authors.forename: N
authors.initials: N
authors.lastname: Roewer
authors.forename: E
authors.initials: E
authors.lastname: Schneider
authors.forename: K
authors.initials: K
authors.lastname: Stoecklein
authors.forename: J
authors.initials: J
authors.lastname: Wermelt
authors.forename: C
authors.initials: C
authors.lastname: Zernak
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects; D018685:Anesthetics, Inhalation / Q000009:adverse effects; D018686:Anesthetics, Intravenous / Q000009:adverse effects; D000932:Antiemetics / Q000191:economics / Q000627:therapeutic use*; D002985:Clinical Protocols; D003907:Dexamethasone / Q000627:therapeutic use; D004329:Droperidol / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl / Q000009:adverse effects; D006801:Humans; D008297:Male; D016017:Odds Ratio; D017294:Ondansetron / Q000627:therapeutic use; D010880:Piperidines / Q000009:adverse effects; D020250:Postoperative Nausea and Vomiting / Q000188:drug therapy* / Q000191:economics / Q000517:prevention & control; D015742:Propofol / Q000009:adverse effects; D000077208:Remifentanil; D012107:Research Design; D012306:Risk
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D000932:Antiemetics; D010880:Piperidines; D017294:Ondansetron; D003907:Dexamethasone; D004329:Droperidol; D000077208:Remifentanil; D005283:Fentanyl; D015742:Propofol
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