Comparing different administration methods of subanaesthetic propofol to mitigate emergence agitation in preschool children undergoing day surgery: a double-blind, randomised controlled study

Background Preschool children who received sevoflurane anaesthesia were associated with a high incidence of emergence agitation (EA). Studies have shown that a subanaesthetic dose of propofol (1 mg/kg) at the end of inhalational anaesthesia could reduce EA in paediatric patients, but the optimal administrations are still under investigation. Methods In a double-blind trial, 160 preschool children (ASA I or II, 2-5 years old) undergoing day surgery of laparoscopic inguinal hernia repair with sevoflurane anaesthesia were randomly assigned into four groups: the control group, single bolus 3 min before the end of the surgery (bolus A), single bolus at the end of the surgery (bolus B) and continuous infusion for 3 min at the end of the surgery (continuous infusion). The dose of propofol in the bolus A group, bolus B group and continued infusion group is 1 mg/kg. The primary outcomes were the incidence and severity of EA assessed by the Paediatric Anaesthesia Emergence Delirium (PAED) scale and Watcha scales. The secondary outcomes included extubation time, emergence time, mean arterial pressure and heart rate. Results The incidence of EA was as follows: 65.0% in the control group, 30.0% in the bolus A group, 32.5% in the bolus B group and 5.0% in the continuous infusion group (p<0.05). Furthermore, the peak PAED scores in the continuous infusion group were significantly lower than those in the other groups. However, extubation time and emergence time showed no differences among groups. Conclusions Continuous infusion of subanaesthetic dose propofol (1 mg/kg) for 3 min at the end of sevoflurane anaesthesia seems to be more appropriate than other administration as it reduced EA and did not prolong the time to wake.