Prevention of postoperative nausea and vomiting with transdermal hyoscine in children using patient-controlled analgesia.

We have studied 40 children aged 6-14 yr undergoing abdominal surgery under general anaesthesia with extradural block; they were allocated randomly to receive transdermal hyoscine (loading dose 140 micrograms, followed by 5 micrograms h-1) or placebo for the duration of postoperative analgesia with PCA morphine. There was a significant (P < 0.001) reduction in the incidence of postoperative nausea and vomiting in the treated group compared with the placebo group during the first 48 h after operation. The treated group also had a significantly increased incidence of sedation (P < 0.02) and dry mouth (P < 0.01).