Eeg entropy measures in anesthesia

1. What is EEG entropy?
2. How is EEG signal used to measure the depth of anaesthesia?
3. What is entropy in anesthesia?

What is EEG entropy?

Entropy is a quantitative EEG device which captures a single-lead frontal EEG via a 3-electrode sensor applied to the patient's forehead. The system calculates the "spectral entropy" of the electroencephalogram (EEG) signals, which is a measure of the degree that the power spectrum is uniform.

How is EEG signal used to measure the depth of anaesthesia?

The main principle involved is that increasing depth of anaesthesia causes increase in the regularity of the EEG, which can be used to estimate the depth of anaesthesia. The signals are divided into State entropy (SE) and Response entropy (RE) based on the two frequency bands (SE-0.8-32 Hz and RE-0.8-47 Hz).

What is entropy in anesthesia?

Entropy monitoring provides quantitative measurement of depth of anaesthesia. The RE scale ranges from 0 (no brain activity) to 100 (fully awake) and the SE scale ranges from 0 (no brain activity) to 91 (fully awake). The clinically relevant target range for entropy values is 40-60.