Vomiting and recovery after outpatient tonsillectomy and adenoidectomy in children : comparison of four anesthetic techniques using nitrous oxide with halothane or propofol

The authors' purpose in this study was to compare prospectively four different anesthetic induction and maintenance techniques using nitrous oxide with halothane and/or propofol for vomiting and recovery after outpatient tonsillectomy and adenoidectomy procedures in children. Eighty unpremedicated children, aged 3-10 yr, were assigned randomly to four groups: group H/H, 0.5-2% halothane induction/halothane maintenance; group P/P, 3-5 mg.kg-1 propofol induction and 0.1-0.3 mg.kg-1.min-1 propofol maintenance; group H/P, 0.1-0.3 mg.kg-1.min-1 halothane induction/propofol maintenance; and group P/H, 3-5 mg.kg-1 propofol induction and 0.5-2% halothane maintenance. Nitrous oxide (67%) and oxygen (33%) were administered in all the groups. Other treatments and procedures were standardized intra- and postoperatively. Results of postoperative vomiting and recovery were analyzed in the first 6 h and beyond 6 h. Logistic regression showed that vomiting occurred 3.5 times as often when halothane was used for maintenance of anesthesia (groups H/H and P/H) compared with the use of propofol (groups P/P and H/P; Odds Ratio 3.5; 95% confidence interval 1.3 and 9.4, respectively; P = 0.012). A significant association between vomiting ( < 6 h: yes/no) and discharge times ( > 6 h: yes/no) (Odd's Ratio = 3.6; 95% confidence interval: 1.02, 12.4, respectively) (P = 0.046) was shown. However, no significant differences among the groups in the incidence of vomiting beyond 6 h, recurrent vomiting, or hospital discharge times were shown. After tonsillectomy and adenoidectomy procedures, despite reduced postoperative vomiting with use of propofol rather than halothane, along with nitrous oxide for anesthetic maintenance, the authors found no differences in "true" endpoints such as unplanned admissions or discharge times. Among the groups, the main factor that delayed hospital discharge beyond 6 h was vomiting within the first 6 h.