title: Nausea and vomiting following thyroid and parathyroid surgery.
abstract: OBJECTIVE
  To determine the incidence of postoperative nausea and vomiting (PONV) following thyroid and parathyroid surgery. To determine whether PONV is reduced when propofol is used for maintenance of anesthesia as compared to isoflurane and to evaluate the costs and resource consumption associated with these two anesthetic regimens.
  
  
  METHODS
  Randomized, prospective study.
  
  
  METHODS
  University-affiliated hospital--a referral center for endocrinologic surgery.
  
  
  METHODS
  118 ASA physical status I and II patients, aged 18 years and older, undergoing elective thyroid or parathyroid surgery.
  
  
  METHODS
  Patients received either isoflurane (0.5 to 1.3% end-tidal) or propofol (50 to 200 micrograms/kg/min) for maintenance of anesthesia. All patients received propofol for induction of anesthesia, succinylcholine or vecuronium, nitrous oxide, and fentanyl. Prophylactic antiemetics were not administered. Postoperative pain was treated with ketorolac, fentanyl, or acetaminophen.
  
  
  RESULTS
  Signs and symptoms of nausea and vomiting were graded on a four point scale as 1 = no nausea; 2 = mild nausea; 3 = severe nausea; 4 = retching and/or vomiting. Grades 3 and 4 were grouped together as PONV. The combined incidence of PONV was 54% over the 24-hour postoperative evaluation period. PONV was significantly more common in patients receiving isoflurane than propofol for maintenance of anesthesia (64% vs. 44%). In women (n = 87), the incidence of PONV was significantly greater in those patients who received isoflurane than those who received propofol for maintenance (71% vs. 42%). However, in men (n = 31), there was no significant difference in PONV between anesthetic regimens (47% with isoflurane vs. 50% with propofol). There were no differences in the duration of stay in the postanesthesia care unit, time to discharge from the hospital, or local wound complications (hematomas) between groups. The use of propofol for maintenance of anesthesia was associated with an additional cost, relative to the isoflurane group, of $54.26 per patient.
  
  
  CONCLUSIONS
  Patients undergoing thyroid or parathyroid surgery are at high risk for the development of PONV. Propofol for maintenance of anesthesia, although more expensive than isoflurane, reduces the rate of PONV in women.
authors.affiliation: Department of Anesthesia, University of California, San Francisco School of Medicine 94115, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Sonner
authors.forename: J M
authors.initials: JM
authors.lastname: Hynson
authors.forename: O
authors.initials: O
authors.lastname: Clark
authors.forename: J A
authors.initials: JA
authors.lastname: Katz
mesh_terms: D000328:Adult; D000368:Aged; D018686:Anesthetics, Intravenous; D005260:Female; D006801:Humans; D007530:Isoflurane; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000209:etiology*; D010280:Parathyroid Glands / Q000601:surgery*; D011183:Postoperative Complications; D015742:Propofol; D011446:Prospective Studies; D013961:Thyroid Gland / Q000601:surgery*; D014839:Vomiting / Q000209:etiology*
chemical_list: D018686:Anesthetics, Intravenous; D007530:Isoflurane; D015742:Propofol