ABRET Certified Neurophysiologic Intraoperative Monitor (CNIM) Practice Exam 2025 - Free CNIM Practice Questions and Study Guide

Etomidate is a short-acting intravenous anesthetic agent often used for induction in anesthesia. It primarily acts as a GABA receptor agonist which can influence various neurophysiological parameters during surgeries. When evaluating its effects on Motor Evoked Potentials (MEPs) and Somatosensory Evoked Potentials (SSEPs), it is understood that etomidate can lead to an increase in the amplitude of these potentials.

The increase in amplitude occurs because etomidate has a relatively selective action that maintains the integrity of the neural pathways responsible for generating MEPs and SSEPs. In particular, it allows for continued neural excitability and signal propagation without significantly depressing the central nervous system to the same extent as some other anesthetic agents, like propofol or volatile anesthetics.

As a result, during monitoring, an increase in amplitude can be observed as etomidate does not significantly compromise the conduction in the pathways assessed by MEPs and SSEPs. This property makes etomidate a favorable choice for surgeries where neurophysiological monitoring is critical, as it supports the visibility of these evoked responses, aiding in the assessment of neural function during procedures.