Anesthetics and Auditory, Visceral, and Heat Evoked Potentials

Influence of Anesthetics on Sedation and Antinociception: an Analysis of Auditory Evoked, Visceral Evoked and Heat Evoked Potentials

The aim of the present study is to investigate and quantify the influence of commonly used anesthetics on auditory and pain evoked potentials.

During surgery patients are exposed to different auditory and sensory stimuli. In this study we investigate the influence of different anesthetics to alertness and nociception. In addition to auditory stimuli (AEP as a measure of sedation), Contact Heat Evoked Potential Stimuli (CHEPS), and esophageal evoked potentials from the lower 1/3 of the esophagus are measured to quantify the effects of anesthetics. 60 Volunteers are enrolled into this study. For each drug, three different levels are measured:

• level 1 no medication
• level 2 low dose of medication
• level 3 light sedation dose (volunteer responds to command)

Four drugs are measured in the study:

propofol, sevoflurane, S-ketamine and remifentanil.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status 1-2

Exclusion Criteria:

• drugs that effect the central nervous system
• neurological or psychiatric diseases
• contraindications against propofol, sevoflurane, S-ketamine or remifentanil
• any damages or loss of hearing
• heartburn or any stomach diseases