title: Dose-range effects of propofol for reducing emetic symptoms during cesarean delivery.
abstract: OBJECTIVE
  To evaluate the efficacy and safety of propofol at subhypnotic doses for reducing emetic symptoms in parturients undergoing cesarean delivery under spinal anesthesia.
  
  
  METHODS
  In a randomized, double-masked trial, 80 patients received lidocaine intravenously 0.1 mg/kg (for injection pain relief) followed by either placebo or propofol at three different doses (0.5 mg/kg per hour, 1.0 mg/kg per hour, 2.0 mg/kg per hour) (n = 20 in each group) immediately after clamping of the umbilical cord. Emetic episodes and safety assessments were performed during spinal anesthesia for cesarean delivery. To estimate a sufficient sample size, it was calculated that 20 patients per group would be required with alpha =.05 and beta =.2.
  
  
  RESULTS
  The rate of patients experiencing no emetic symptoms in an intraoperative, postdelivery period was 45% with propofol 0.5 mg/kg per hour (P =.5), 80% with propofol 1.0 mg/kg per hour (P =.011), and 80% with propofol 2.0 mg/kg per hour (P =.011), compared with placebo (40%). No clinically serious adverse events caused by the study drugs were observed.
  
  
  CONCLUSIONS
  Propofol 1.0 mg/kg per hour is the minimum effective subhypnotic dose for reducing emetic symptoms during cesarean delivery. Increasing the dose to 2.0 mg/kg per hour provides no further benefit.
authors.affiliation: Department of Anesthesiology, University of Tsukuba Institute of Clinical Medicine, Tsukuba City, Ibaraki, Japan. yfujii@igaka.md.tsukuba.ac.jp
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Fujii
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Numazaki
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000775:Anesthesia, Spinal / Q000379:methods; D002585:Cesarean Section / Q000009:adverse effects* / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007262:Infusions, Intravenous; D008012:Lidocaine / Q000008:administration & dosage; D020250:Postoperative Nausea and Vomiting / Q000209:etiology / Q000517:prevention & control*; D011247:Pregnancy; D011336:Probability; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D008012:Lidocaine; D015742:Propofol