Device (1) for determining a combined
anesthetic effect on a patient anesthetized by means of a combination of at least two active substances characterized in that the device is set up to perform the following steps: Determining the concentration of each
active ingredient at the
site of action using pharmacokinetic and / or pharmacodynamic models; Summarizing the effect of all active ingredients within each class of active ingredients used, whereby the
potency of the active ingredients is added if they act on the same
receptor type; Determining the synergistic interaction between at least two active substances used in
anesthesia by determining a combined
potency N of the
anesthetic effect of the applied active substances, based on a mean
anesthetic efficacy of the active substances used and an interaction term. determining an NSRI index value NSRI = 100 ∗ ( 1 − ( N / N ' ) sl 1 + ( N / N ' ) sl ) , where - N is the combined power, - N' is a specific value at which an NSRI value of 50% is reached. - and sl is a
slope factor for a transformation from N to NSRI; Display of the NSRI index value using a
display device (29); and Display of at least one comparative value (67, 69) for
anesthesia management and / or patient
arousal by means of the
display device (29).