Evoked Potential Monitoring Flashcards Preview

Desflurane affects somatosensory evoked potentials by:

Evoked potentials are used to ----- the integrity of a neural pathway

What are the four types of evoked potentials

Evoked potentials are produced by applying ----- to a neural pathway

Evoked potentials are produced by applying current to a neural pathway. For example, SSEPs are produced by applying current to a peripheral nerve - most commonly the ----- n. or ----- n.

Evoked potentials are produced by applying current to a neural pathway. The electrical current travels from the peripheral nerve to the ----- side of the cerebral cortex.

Which types of evoked potentials monitor the integrity of the dorsal column (medial lemniscus)?

SSEPs monitor the integrity of the dorsal column (medial lemniscus). This region of the cord is perfused by the ------ spinal arteries

Which types of evoked potentials monitor the integrity of the corticospinal tract?

MEPs monitor the integrity of the corticospinal tract. This region of the cord is perfused by the ----- spinal artery

SSEPs do not monitor the Anterior cord

SSEPs do not monitor the Anterior cord and therefore aren't interchangeable with MEPs

Which two components of the evoked potential waveform are we most concerned with?

The ---- of the evoked potential waveform represents the strength of the nerve response

The ---- of the evoked potential waveform represents the speed of nerve conduction

Losing the evoked potential signal (or recording a diminished response) suggests ----- to the neural pathway being monitored

Losing the evoked potential signal (or recording a diminished response) suggests ischemia to the neural pathway being monitored. For this reason, it is imperative to administer an anesthetic that ----- with the evoked potential monitoring technique

As a general rule, you should be concerned about nerve ischemia when amplitude decreases by >/= --- percent

As a general rule, you should be concerned about nerve ischemia when amplitude decreases by >/= 50 percent or latency increases by /= --- percent

Volatile anesthetics ----- amplitude

Volatile anesthetics decrease amplitude and ----- latency

Volatile anesthetics decrease amplitude and increase latency. The addition of N2O makes this -----.

Volatile anesthetics decrease amplitude and increase latency. The addition of N2O makes this worse. Hypoxia is a confounding factor that affects amplitude and/or latency

Volatile anesthetics decrease amplitude and increase latency. The addition of N2O makes this worse. ----- is a confounding factor that affects amplitude and/or latency

A. Hypercarbia

B. Hypocarbia

Volatile anesthetics decrease amplitude and increase latency. The addition of N2O makes this worse. -----  is a confounding factor that affects amplitude and/or latency

A. Hyperthermia

B. Hypothermia

The best anesthetic technique to preserve evoked potentials is ----- without N2O

The best anesthetic technique to preserve evoked potentials is TIVA without N2O. Some institutions only use TIVA when evoked potentials are monitored

If you use a volatile agent, it's recommended that you use --- MAC or less

If you use a volatile agent, it's recommended that you use 0.5 MAC or less. You can supplement with intravenous agents (propofol, opioid), but do not use ----- as this combination can further impair the signal

Muscle relaxants should not be used when which type of evoked potentials are monitored?

Muscle relaxants should not be used when MEPs are monitored, however, a ----- may be given during induction so long as it will be metabolized before evoked potentials are required

Which IV induction agent enhances the evoked potentials signal?

Which type of evoked potentials are most resistant to the effects of anesthetics

Brainstem auditory evoked potentials (BAEPs) are most resistant to the effects of anesthetics, and thus any anesthetic technique may be used

Which type of evoked potentials is the most sensitive to the effects of anesthetic agents, and thus are seldom used?

If the evoked potential signal diminishes or goes away during surgery, the surgeon should investigate a ----- cause

If the evoked potential signal diminishes or goes away during surgery, the surgeon should investigate a mechanical cause (such as surgical distraction). Anesthetic goals include improving neural tissue perfusion by increasing -----.

If the evoked potential signal diminishes or goes away during surgery, the surgeon should investigate a mechanical cause (such as surgical distraction). Anesthetic goals include improving neural tissue perfusion by increasing BP, ----- expansion
 

If the evoked potential signal diminishes or goes away during surgery, the surgeon should investigate a mechanical cause (such as surgical distraction). Anesthetic goals include improving neural tissue perfusion by increasing BP, volume expansion, and ----- (if anemic)

If the evoked potential signal diminishes or goes away during surgery, the surgeon should investigate a mechanical cause (such as surgical distraction). Anesthetic goals include improving neural tissue perfusion by increasing BP, volume expansion, and transfusion (if anemic). Normalizing gas tensions may also help.

If the evoked potential signal diminishes or goes away during surgery, the surgeon should investigate a mechanical cause (such as surgical distraction). Anesthetic goals include improving neural tissue perfusion by increasing BP, volume expansion, and transfusion (if anemic). Normalizing gas tensions may also help.

Communication with the surgical team is essential.

Desflurane affects somatosensory evoked potentials by:

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