Bayesian-based propofol infusion advisory tool validation

Target-controlled infusion has been developed towards a mature technology routinely used in clinical practice to target plasma and effect-site concentration for drug infusion such as propofol, instead of volumetric infusion using inaccurate units per hour. The cerebral drug effect is routine measured by a “depth of anaesthesia monitor”, based on a processed EEG system, such as the qCON (Fresenius, Brésins, France). Nowadays, the anesthesiologist has to combine the independent information from the propofol effect-site concentration on the pump display and the qCON index from the EEG monitor to make an accurate decision in order to optimize drug administration. However, the effect-site concentration can be linked to effect as measured by qCON and can be modelled in an sigmoidal “E-max” curve. This could allow the clinician to observe the combined information in an advisory display.

As the relationship between effect-site concentration of propofol and qCON is dynamically and continuously changing over time, a computer algorithm could be helpful to personalise the sigmoidal “Emax” curve on the advisory display towards the individual patient and his/her condition (e.g. other drugs given simultaneously during propofol-based anesthesia). Adjusting predictions using prior information, based on measurements, could continuously update the E-max curve. This can be done by applying Bayesian-adjustment implemented in an advisory tool that provides dose titration advices for the clinician aiming to reach a corresponding preset desired qCON value in a continuous matter.

To assess the accuracy and the clinical feasibility of a Bayesian-based, patient-individualized, pharmacodynamic advisory system to optimize propofol effect-compartment-controlled administration using the qCON index as a controlled variable versus qCON-guided effect-compartment controlled propofol administration without the input of the advisory system.

Continues registration of required parameters for advisory tool from start of anesthesia induction till the end of propofol infusion.

Also, during recovery, we will compare the time from stop propofol infusion until opening of the eyes on command and orientation. Hereby, orientation will be defined as saying name and date of birth on request.

target controlled propofol infusion with and without advisory tool.