ABSTRACT
Objective To compare the efficacy of closed-loop infusion of propofol for surgery in pe-diatric patients of different ages. Methods Forty-five pediatric patients of both sexes, weighing 10-63 kg, of American Society of Anesthesiologists physical statusⅠ or Ⅱ, scheduled for elective urologic sur-gery under general anesthesia, were divided into 3 groups(n=15 each)according to the age: infant group (1-3 yr), pre-school group(4-6 yr)and school-age group(7-12 yr). The bispectral index(BIS)moni-tor was connected to the closed-loop anesthesia delivery system, and the system automatically regulated the target plasma concentration of propofol to achieve a target BIS value of 45-55 during maintenance of anes-thesia. Remifentanil was given by target-controlled infusion at a target plasma concentration and rocuronium was intravenously injected when necessary during surgery. BIS40-60time percentage(percentage of time of BIS value maintaining at 40-60 in time of closed-loop infusion), median performance error(MDPE), me-dian absolute performance error(MDAPE), wobble and global score were recorded. The consumption of propofol, mean target plasma concentration and regulating frequency and consumption of remifentanil and rocuronium were recorded during surgery. Extubation time or laryngeal mask airway removal time, time to eye-opening and time of regaining consciousness were recorded. Results The BIS40-60time percentage was significantly higher, MDPE, MDAPE, wobble and global score were lower in pre-school and school-age groups than in infant group(P<005). Compared with pre-school group, the consumption of remifentanil was significantly decreased(P<005), and no significant change was found in BIS40-60time percentage, MDPE, MDAPE, wobble or global score in school-age group(P>005). There was no significant differ-ence in the consumption of propofol, mean target plasma concentration, regulating frequency, consumption of rocuronium, extubation time or laryngeal mask airway removal time, time to eye-opening or time of regai-ning consciousness among the 3 groups(P>005). Conclusion Closed-loop infusion of propofol produces better stability for surgery in pre-school and school-age children than in infants.