Alteration of Blood-Brain-Barrier Permeability at Loss of Consciousness in Delirious Patients Recorded With Direct-Current Electroencephalography (ACDC)

With this trial we aim to characterize the intraoperative signatures of the Direct-Current-Electroencephalogram (DC-EEG) of elderly patients developing a PostOperative Delirium (POD) compared to patients who do not develop a POD. We hereby intend to gain a better understanding of the electrical potential at the blood-brain-barrier (measured with DC-EEG) during general anaesthesia. Second, we want to study the effect of age on the DC-EEG by comparing a younger (18-30y) to an elderly cohort (\>70). Third, we aim to couple the DC-EEG signatures to blood sample analysis in order to understand the relationship between metabolic, inflammatory and vascular reaction with the intraoperative DC-EEG.