title: Caffeine for the prevention of postoperative nausea and vomiting.
abstract: BACKGROUND
  Postoperative nausea and vomiting (PONV) is common after ambulatory surgery performed under general anesthesia. Anecdotal evidence suggests that caffeine may be useful in preventing PONV.
  
  
  OBJECTIVE
  The aim of the study was to determine efficacy of intravenous (IV) caffeine given prior to surgery is effective prophylaxis against PONV.
  
  
  METHODS
  We conducted a prospective, randomized, double-blind, placebo-controlled study.
  
  
  METHODS
  Patients at moderate or high risk of PONV were randomized to receive IV caffeine (500 mg) or saline placebo during general anesthesia; all patients received dexamethasone and dolasetron.
  
  
  METHODS
  Statistical comparisons were tested using bivariable linear and logistic regression for each outcome and then adjusted for high/low risk.
  
  
  RESULTS
  Nausea in the postanesthesia care unit (PACU) was more common in the caffeine (16 of 62 patients) than the placebo group (seven of 69; P = 0.02). There were no significant differences in the use of rescue antiemetics in the PACU, in the incidence of nausea or vomiting over 24 h postoperatively, nor in other outcomes (headache, fatigue, or overall satisfaction) either in the PACU or at 24 h; time-to-discharge was similar for both groups.
  
  
  CONCLUSIONS
  Caffeine was not effective in the prevention of PONV or headache, and did not improve time-to-discharge or patient satisfaction.
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Steinbrook
authors.forename: Frances
authors.initials: F
authors.lastname: Garfield
authors.forename: Stacey H
authors.initials: SH
authors.lastname: Batista
authors.forename: Richard D
authors.initials: RD
authors.lastname: Urman
keywords: Antiemetic prophylaxis; caffeine; postoperative nausea; postoperative vomiting