On-line estimation of propofol pharmacodynamic parameters

A novel advisory system, the Anesthesia Advisory Display (AAD) has been recently developed. It displays information about actual and future predictions of anesthetic drug concentrations mapped to clinical end-points such as BIS, basing on the actual infusion rate combined with population pharmacokinetic and interaction pharmacodynamic (PKPD) models. According to the large variability observed among patients in clinical end-points to the same dosing history, a population model could fail in predicting the real patient\´s behavior: an "individualized" model is then necessary. An on-line estimation of the model\´s parameter for the single patients has been developed, basing on the extended Kalman filter algorithm. The method has been tested on data of 40 patients from a previous clinical study and the prediction of the individual models have been compared with the population model\´s