Recording the middle latency response of the auditory evoked potential as a measure of depth of anaesthesia. A technical note

Abstract

The middle latency response of the auditory evoked potential may be useful as an indicator of the hypnotic state during anaesthesia. However, it is difficult to record in some circumstances. This communication provides some suggestions and guidance for those not familiar with the technique.

Does Depth of Anesthesia Influence Postoperative Cognitive Dysfunction or Inflammatory Response Following Major ENT Surgery?

“…The AAI from the MLAEP was calculated using the A-line monitor [16,17]. AAI values range from 0 to 60 where 60 indicates an awake patient.…”

“…MLAEP was elicited with a bilateral click stimulus of 32-db intensity and 2 ms duration. Three silver/silver chloride electrodes (A-line AEP electrodes) were positioned at mid forehead (+), left or right forehead (reference electrode), and left or right mastoid (-) [16,17]. Extraction of the MLAEP was done using a short movingtime average technique together with an ARX evolution model.…”

“…Extraction of the MLAEP was done using a short movingtime average technique together with an ARX evolution model. These calculations of the AAI have been described elsewhere in detail [16,17].…”

Wave V Detection Using Instantaneous Energy of Auditory Brainstem Response Signal

“…Taking care of the gain of the amplifier is important. It must be low enough to avoid saturation [23] . Frequency bandwidth is important in order to get the correct range for the signal.…”

EMD-based EEG signal enhancement for auditory evoked potential recovery under high stimulus-rate paradigm

“…The amplifier was set to band-pass 10-1000 Hz at 6 dB/octave, and the sampling rate at 20 kHz. The filter parameters are in accordance with typical middle latency AEP studies [28,29]. A single channel of raw EEG data is acquired from FCz site according to 10/20 international standard.…”