The accuracy of a Bayesian-based, patient-individualized, pharmacodynamic advisory system to optimize propofol administration using the qCON index as a controlled variable. A comparison versus standard of care.

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 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.

Randomized-controlled trial for medical equipment (i.e. the new advisory tool)

In both groups, propofol administration will be executed by an anesthesiologist
or nurse anesthesiologist.

The advisory system display will be blinded in the control group (in order to
obtain all data for post-hoc analysis).

Informed consent is obtained from all patients prior to randomization. During
the case, the patients will be monitored according to routinely clinical
standards, such as qCON, ECG, Non-invasive blood pressure (NIBP), Pulse
Oximetry (SpO2). Each patient will receive a venous access in the non-dominant
arm or hand for drug and fluid infusion as per clinical practice.

The administration of propofol following the advices of the Bayesian advisory
tool would hypothetically lead to optimize patient care. As such, a benefit
might be expected compared to standard clinical practice (less accumulation of
drug, faster recovery from anaesthesia, less overshoot in propofol effect when
dose adjustments are performed etc.).

Safety of the application of the Bayesian advisory tool is guaranteed by the
fact that the
decision of dose adjustment remains under control of the anesthesiologist at
all times during this study. It is up to this clinician to follow the advices
given by the display system or not.

The risk of participating in this study is identical to the risk of the normal
clinical procedure.