Wang et al, Anesth Analg 2000;91:1404-7

Reviewed by: R. Prasad, MD

Summary:

• 225 women (45x5 groups) having thyroidectomy under GA
• GA: propofol, glycopyrrolate, fent 2mcg/kg, vecuronium, isoflurane. Addtl fentanyl as needed. Reversed at end.
• 24hr observation. Blinded observers. Complete response = no vomiting, no antiemetics in 24hrs.
• Power analysis: 90% chance of detecting signif (p<0.5) difference if PONV 60% in control, 30% reduction in treatment group (to 42%). Needed 40pts/group.
• Studied different doses of dexameth: 0 (saline control), 1.25, 2.5, 5.0, 10.0 mg.
• Similar groups (age, wt, height, last menstrual cycle, duration of surgery/anesthesia, total fent, hosp stay)
• Findings (some #s approximated):
• 5, 10 mg equally effective (%, vs. Saline: total N/V 20% vs. 51%, >4 episodes vomiting 2% vs. 11%, rescue tx 12% vs. 23%, complete response 88% vs. 65%)
• 0, 1.25 equally ineffective
• 2.5 partially effective: decreased total incidence of N/V, but no diff vs. placebo in Nausea, Vomiting, # vomiting episodes (0-4 or >4), need for rescue, or complete response