Is TIVA with remifentanil/propofol superior to sevoflurane/N2O regarding PONV in children undergoing strabismus surgery?

Background: Postoperative nausea and vomiting (PONV) is still one of the ma jor problems in strabismus surgery, especially in children. In recent years many studies have been published, suggesting that choosing propofol as the anaesthetic agent may help to reduce the high incidence of PONV in childre n undergoing strabismus surgery. Experience with remifentanil in children i s still very limited and little is known,whether propofol in combination wi th this new short acting opioid is also superior regarding PONV in squint s urgery compared to sevoflurane/N(2)0. Additionally, little is known, whethe r the type of operation or the muscle which is operated on has any influenc e with respect to PONV. Methods: Following sample size estimation, ethics committee approval and pa rents informed consent in a prospective, randomised, observer-blind study 1 05 ASA I and II children aged 3-8 years scheduled for elective strabismus s urgery were assigned into one of the following groups: Group TIVA (propofol /remifentanil, n=53): anaesthesia was induced by remifentanil 0.5 mu g kg(- 1) min(-1) over 2 min (loading phase), followed by 3 mg kg(-1) propofol alo ng with 30% O-2 in air. After endotracheal intubation anaesthesia was maint ained initially with remifentanil 0.25 mu kg(-1) min(-1) and propofol 10 mg kg(-1) h(-1) by constant infusion. In the course of the operation the infu sions of the anaesthetics were adjusted to the decreasing need for anaesthe sia. Group VOLATIL (sevoflurane/N2O, n=52):anaesthesia was induced by inhal ation of sevoflurane along with 50% O-2 in N2O. After endotracheal intubati on anaesthesia was maintained with sevoflurane 1.0-1.5 MAC along with 30% O -2 in N2O and in the course of the operation the administration of the inha led anaesthetics was adjusted correspondingly. Preoperatively collected data included gender, age, weight and history of P ONV. Intraoperatively collected data consisted of data belonging to routine monitoring (heart rate, blood pressure, peripheral oxygen saturation and t emperature) as well as the duration of the operation and anaesthesia and sp ecific data regarding the operation (including the number and type of muscl es as well as the kind of operation). Data collected within the first 24 ho urs postoperatively in the recovery room and on the ward by blinded observe rs included any PONV events as well as the antiemetics and analgesics appli ed. Results: Vomiting was observed less frequently in the TIVA-group than in th e VOLATIL-group (21 of 53 vs. 32 of 52, p=0.03) within the first 24 hours p ostoperatively. Posterior fixation suture ("faden-operation") compared to o ther operations was followed rather frequently by nausea and vomiting (30 o f 44 and 33 of 44, respectively), whereas recessions were rarely associated with nausea and vomiting (12 of 35 and 9 of 35, respectively). Conclusions: TIVA with propofol/remifentanil proved to be a suitable form o f anaesthesia for children in this setting. Propofol showed advantages over with respect to PONV after squint surgery in children also when applied in the combination with remifentanil. TIVA with propofol/ remifentanil may th erefore be one way to reduce the high incidence of PONV in this setting, be aring in mind, that PONV is not only influenced by the regimen of the gener al anaesthesia but rather by the combination of many other factors, in part icular the type of operation.