EXAM 2 Reading (N.Ch19) Flashcards
Which of the following drugs would be most likely to affect the latency and amplitude of brainstem auditory evoked potentials (BAEPs)?
Sevoflurane
BAEPs are not significantly affected by
benzodiazepines, ketamine, propofol, muscle relaxants, N2O, or barbiturate
Inhalation agents can affect_____and the effect is_______
BAEPs and the effect is proportional to the dose administered.
Which of the following would have the greatest effect on brainstem auditory evoked potentials?
Sevoflurane
Motor evoked potentials using magnetic stimulation are contraindicated in patients who have ?
Pacemaker
Previous Craniotomy
SPinal/Bladder stimulator
Metallic FB
Which evoked potential monitoring modality is specific to cranial nerve VIII and is particularly useful in acoustic neuroma surgery?
Brain auditory evoked potential
Brain auditory evoked potentials evaluate the function of
cranial nerve VIII
Useful in acoustic neuroma surgery.
Brain auditory evoked potentials
Which of the following agents are least likely to alter the latency or amplitude of somatosensory evoked potentials? (select two)
Ketamine
Etomidate
Most anesthetic agents will alter the latency or amplitude of somatosensory evoked potentials except for
opioids, ketamine, and etomidate.
Which electroencephalogram (EEG) findings would be consistent with light anesthesia or profound surgical stimulation?
High frequency, low voltage activity
Surgical stimulation or light anesthesia would display
high frequency, low voltage activity on the EEG monitor.
HFLV
Which of the following agents will not produce a significant change in the latency or amplitude of somatosensory evoked potentials? (select two)
Fentanyl
Ketamine
In normal doses, ketamine, etomidate, and opioids
do not produce a significant change in the latency or amplitude of somatosensory evoked potentials
The administration of intravenous anesthetics in general anesthetic (not pain control) doses
the latency and amplitude of SSEPs will be affected, but not to the degree seen with inhaled anesthetics.
The administration of muscle relaxants will not affect
somatosensory evoked potentials
The administration of muscle relaxants interfere with
or completely block motor-evoked potentials.
Inhaled anesthetics will DAIL
the latency and decrease the amplitude of somatosensory evoked potentials.
When should the auditory transducer be placed when monitoring brainstem auditory evoked potentials?
After positioning of the head
The BAEP transducer should be positioned after the head is positioned. This produces the best results, and also prevents
abrasive injury to the ear canal.
Which evoked potential is useful in evaluating descending motor pathways?
Motor evoked potentials
MEP assesses (think MD)
descending motor pathways
BAEP, SSEP, and VEP give data about
ascending sensory neural pathways.
Which diagnostic aid would most accurately reflect an interruption of ANTERIOR spinal cord perfusion in a patient undergoing surgery involving cross-clamping of the thoracic aorta?
Motor Evoked potentials. This test is not often used, however, because it precludes the use of muscle relaxants.
Somatosensory evoked potentials (SSEPs) and EEG would be useful in assessing the but
central nervous system of a patient undergoing surgery,
Neither assesses the integrity of the anterior spinal cord
SSEPs or EEG
SSEPs assess the sensory pathways in the
dorsal spinal cord
Cross clamping of the thoracic aorta, Right radial arterial line would be most appropriate for monitoring
pressures proximal to the clamp.
An anesthetized patient undergoing neurologic surgery has a monitor in place that utilizes a stroboscopic flash with recording electrodes placed on the scalp. What intraoperative test is being performed?
Visual evoked potentials
Which of the following tests would be most appropriate for testing neural integrity during posterior fossa surgery?
Brainstem auditory evoked potentials
Somatosensory evoked potentials assess the
dorsal spinal column and sensory cortex
SSEPs best for monitoring during
spinal surgery, carotid endarterectomy, and aortic surgery.
Visual evoked potentials assess the integrity of the
optic nerve and upper brainstem and are best for monitoring during pituitary resection.
Best for monitoring during pituitary resection:
VEPs
The wake-up test assesses movement and evaluates the integrity of the
motor tracts in the ventral spinal column.
Which type of visual evoked potential is performed on an awake patient?
Patterned VEPs
During Visual Evoked Potentials (VEPs), the patient is presented
a visual stimulus for a select number of times, then the cerebral responses are dispayed after being amplified and averaged on a computer.
There are two types of VEPs:
patterned and unpatterned.
Patterned tests are used on
awake patients.
Which intravenous agents would be most capable of producing burst suppression on the EEG? (select two)
Etomidate
Propofol
2 only IV agents capable of BURST SUPPRESION on EEG
Etomidate
Propofol
Which of the following conditions is known to produce increased latency in brainstem auditory evoked potentials?
Hypocapnia
Low PCO2 (hypocapnia) on BAEPs
exaggerates BAEPs, resulting in an increased latency.
Can result in increased latency and prolonged interpeak intervals
Hypothermia (not hyperthermia)
What is the stimulus used in the monitoring of BAEPs?
A broadband, repeating click
What is done during brainstem auditory evoked potentials?
A standard broadband repeating click that is delivered through an earphone that is placed in the auditory canal is used
In which patient would motor-evoked potentials using magnetic stimulation be contraindicated?
A 55 year-old male with a bladder stimulator
Are useful in the monitoring of functional integrity of motor tracts, namely, the corticospinal tract
Motor evoked potentials (MEPs)
MEPs, The stimuli can be
magnetic or electrical, with either the spinal cord or the motor cortex used as the site of stimulation.
Patients with spinal or bladder stimulators, metallic foreign bodies, pacemakers, or a previous craniotomy
should not undergo MEP via magnetic stimulation.
Somatosensory evoked potentials are useful for
monitoring during a carotid endarterectomy
Brainstem auditory evoked potentials are useful for monitoring this function ?
are useful for monitoring basic brainstem function
Useful for monitoring basic brainstem function
Brainstem auditory evoked potentials
