Relationship Between the Depth of Anesthesia and Auditory Evoked Potentials (P3a)

Summary

The interest of perioperative cerebral monitoring and in particular electroencephalography (EEG) to reduce neurological and cognitive damage in surgery has been the subject of abundant research and corresponds to a crucial issue. There is increasing evidence to suggest that inadequate (overdosed) anesthesia for patient characteristics and intraoperative hemodynamic instability is associated with an increased risk of complications including postoperative cognitive dysfunction and postoperative mortality.

However, these devices have many limitations in use, in particular their consideration of the muscle component of the electrical signal collected.There are other identifiable EEG signals that can be used to assess the depth of anesthesia, in particular auditory evoked potentials (AEPs).

The so-called rough sound waves correspond to a formulation composed of the rapid repetition of acoustic segments, at a frequency of 30 to 150 Hz.This frequency (whether sound or light) induces a temporal activation that captures attention and provokes unpleasant sensations and avoidance strategies when perceived by a subject.

This project aims at overcoming the interaction of the muscular electrical signal by evaluating the electrophysiological response (auditory evoked potentials) to particular sound stimuli, called "rough", thus underpinning the understanding of the mechanisms of neurosensory integration and attention during a state of loss of consciousness or altered consciousness.

The hypothesis proposed for this study is the following: the P3a wave (positive wave collected on the EEG during auditory evoked potentials) is altered during general anesthesia, in frequency and amplitude, and thus is indicative of the depth of the anesthetic state.

Conditions

• General Anesthesia

Interventions

DEVICE

Electroencephalogram recording

Brain function monitoring using a Sedline® module (Masimo corporation) to evaluate the state of the brain under anesthesia

OTHER

Auditory stimulation

Monotonous sounds are sent via binaural headphones: a standard item and a distractor item (rough sound). Each stimulus lasts about 300 ms and they are separated by 1.5 to 2 seconds between them; the deviant sound/standard sound ratio is fixed between 1/5 and 1/6.

DEVICE

Transcranial Doppler

Measurement of cerebral blood flow velocity (CFV) with use of Transcranial Doppler ultrasonography. For all patients, CFV (unit cm/s) will be collected over four distinct periods: 1/ baseline or during pre-oxygenation at inspired oxygen fraction (FiO2) of 21% in awake patients; 2/ during anesthetic induction; 3 /deep sleep; 4/ recovery period.

DEVICE

Near-infrared spectroscopy

Continuous measurement of cerebral oxygen saturation (SO2) with Near-infrared spectroscopy (NIRS). For all patients, SO2 (%) will be collected over four distinct periods: 1/ baseline or during pre-oxygenation at FiO2 of 21% in awake patients; 2/ during anesthetic induction; 3 /deep sleep; 4/ recovery period.

Sponsors & Collaborators

• INSERM UMR-942, Paris, France

  collaborator OTHER

• Laboratoire de Mécanique des Solides, École polytechnique

  collaborator UNKNOWN

• M3DISIM Inria Université Paris-Saclay

  collaborator UNKNOWN

• Assistance Publique - Hôpitaux de Paris

  lead OTHER

Principal Investigators

• Joaquim MATEO, MD · Assistance Publique - Hôpitaux de Paris

• Fabrice VALLEE, MD, PhD · Assistance Publique - Hôpitaux de Paris

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-12-31

Primary Completion

2024-12-31

Completion

2024-12-31

Countries

• France

Study Locations