Which model for propofol TCI in children.

For several years, total intravenous anesthesia (TIVA) has demonstrated many advantages that allow consideration of propofol anesthesia as an interesting alternative in pediatric anesthesia. TIVA in children requires calculation and validation of pharmacokinetic (PK) models specifically adapted to the pediatric population. Several PK models based on a 3-compartment approach have been proposed in children: all these models, which integrate only weight as covariable, show increased distribution volumes with a wide interindividual variability. However, as pharmacodynamic (PD) parameters are still debated in children, there is up to now, no PKPD model currently available for pediatric anesthesia. The particular importance to include physiological covariables, as size and age, to describe metabolic processes during growth and maturation in pediatric PKPD models is in agreement with recent allometric scaling works in children. The Schnider's model, a model described in adults that includes numerous covariables, may be adapted and more efficient than the classical pediatric model to describe propofol-PKPD relationship in children over 5 years. Whatever is the model, a pharmacodynamic feed back such as the bispectral index may be useful to counteract the interindividual variability in the pediatric population.