Abstract
The target organ of most substances applied during general anesthesia is the brain. The manifestations of its function include, above all, consciousness.
It is associated with the electrical activity of neurons, which can be easily recorded from the surface of the skull - electroencephalography (EEG). The electrical activity of the brain in anesthesia changes in a predictable way depending on the anesthetic used and its dose.
EEG assessment is difficult but has been greatly simplified by computer development. Therefore, computer-processed EEG (pEEG) may soon become an integral part of monitoring patients under anesthesia.
Anesthesiologists' attention with EEG monitoring initially focused on anesthesia depth indices (eg. BIS, entropy, PSI, qCON, etc.), but brain function cannot be reduced to a single number.
It is also necessary to monitor simultaneously the raw EEG curves and to assess the changes in their shape. When conducting anesthesia, it is important to avoid burst suppression because it is a risk factor for postoperative delirium.
Evaluation of the phase-amplitude coupling makes it possible to quantify the depth of anesthesia in more detail. Processed EEG is used to prevent unattended awareness during anesthesia and to prevent too deep anesthesia, although the benefit has not yet been safely confirmed.
However, pEEG has been shown to reduce recovery times and anesthetic doses. It allows also personalized management of anesthesia, relevant studies are underway.
The most widespread monitors in the Czech Republic are probably BIS, GE Entropy, and Conox. The development of pEEG continues, but its understanding and application require increasing knowledge in many fields.