Propofol maintenance to reduce postoperative emesis in thyroidectomy patients: a group sequential comparison with isoflurane/nitrous oxide

The clinical benefit of propofol anaesthesia in the prevention of postoperative nausea and vomiting (PONV) is still being elucidated despite many studies to date. In this study 64 adult female patients scheduled for thyroidectomy received, in a randomized double-blind fashion, propofol with air or isoflurane with nitrous oxide for maintenance of anaesthesia. The primary response variable was the presence or absence of vomiting in the first six hours. A group sequential design was used to allow interim analysis. After 64 patients, the fourth analysis showed that fewer patients receiving propofol vomited or required an anti-emetic during the first six hours (P < 0.05). There was no significant difference detected in the 6 to 24 hour interval. In this group of female patients, total intravenous anaesthesia (TIVA) with propofol is associated with an early reduction in early postoperative vomiting compared with standard inhalational techniques. This reduction in vomiting does not appear to persist beyond the first six hours.