Abstract
This study evaluated the efficacy of tropisetron compared with tropisetron and a subhypnotic propofol infusion in preventing postoperative vomiting following tonsillectomy. One hundred and forty healthy children, aged four to 12 years, undergoing tonsillectomy were recruited in a randomised, double-blind study. After induction with sevoflurane, anaesthesia was maintained with sevoflurane and nitrous oxide. All patients received tropisetron (0.2 mg/kg up to 5 mg; intravenously) and fentanyl (2 μg/kg; intravenously) and were intubated after atracurium which was reversed with neostigmine (and atropine). The tropisetron-plus-propofol group received a single dose of propofol (1 mg/kg) before intubation and a continuous infusion of propofol throughout surgery at 15 μg/kg/min. Data for postoperative vomiting were grouped into zero to four and four to 24 hour time intervals. A P value of <0.05 was considered statistically significant.
The percentage of patients exhibiting a complete response (no retching or vomiting for 24 hours) was 47.1% (33/70) in the tropisetron-alone group and 72.8% (51/70) in the tropisetron-plus-propofol group (P=0.002). The 0.257 absolute risk reduction of vomiting with the addition of propofol represents a number needed to treat of 3.87, and a risk ratio of 0.51 (95% CI 0.32 to 0.79). Significantly fewer patients vomited in the tropisetron-plus-propofol group than in the tropisetron-alone group during the zero to four post-surgery interval (P=0.016), but the difference was not statistically significant for the four to 24 hour postoperative period (P=0.116). Intraoperative subhypnotic propofol infusion combined with tropisetron is more effective than tropisetron alone in reducing postoperative vomiting after tonsillectomy in children.