Neuro Clinical Monitoring Flashcards
Which test of neuromuscular function consists of continuous stimulation for five seconds at 50 Hz or 100 Hz?
Tetanus
What is the gold standard for measuring core body temperature?
Pulm Artery Cath. The most precise and accurate.
Burst suppression is best characterized on an EEG as:
Alternating episodes of isoelectricty (0 or low voltage) and high voltage active oscillations on an EEG. Denotes minimal neuronal activity.
A frequency of _______ characterizes alpha waves on an EEG and are present in an _____ patient
8-12Hz and alert patient
A frequency of _______ characterizes beta waves on an EEG and are present in an _____ patient
13-25Hz
arousable state of sedation
Loss of cortical electrical activity on an EEG is characterized by?
Complete loss of cortical electrical activity. present in unanesthetized comatose patients - poor prognosis
Jugular venous oximetry monitoring is optimally measured at which vertebrae level?
C1-C2
What neuro clinical monitoring can be done under anesthesia?
- Cerebral Electrical Activity
- Cerebral Blood Flow (CBF)
- Cerebral Oxygen Content
- Intracranial Pressure
- Cerebral Metabolic Rate of Oxygen Consumption
How is cerebral electrical activity monitored?
EEG and EVPs (evoked potentials)
How is cerebral blood flow monitored?
Transcranial Doppler Ultrasound (TCD)
How is cerebral oxygen content monitored?
NIRS
Near Infrared Spectrometry
How is intracranial pressure monitored?
Intraventricular catheters and fiberoptic and intraparenchymal micro transducers
How is cerebral metabolic rate of oxygen consumption (CMRO2) monitored?
JVO2 - jugular venous oximetry or intracerebral partial pressure of oxygen (pO2) electrodes
As ischemia or hypoxia increase, what brain eeg wave changes occur?
beta waves begin to disappear, and low-amplitude delta waves appear. (delta wave usually high amplitude). This progresses to electrical activity impression with occasional bursts of activity.
Wave changes with the onset of ischemia or hypoxia?
Transient increase in beta waves with the eventual development of increased amplitude theta and delta waves.
Describe Delta Waves
0-4Hz. High amplitude, Low Frequency. Associated with deep sleep.
Describe Theta Waves
4-8Hz. Low amplitude, Low Frequency. Light Sleep.
Describe Alpha Waves
8-13Hz. High Amplitude, Moderate Frequency. Inattentive brain, drowsiness - eyes closed
Describe Beta Waves
> 13Hz: Moderate Amplitude, High Frequency. Mental activity, Alertness, Normal Awake
Describe Gamma Waves
> 40Hz: Low amplitude, High Frequency. High-level processing.
Describe the Anesthetic Management when measuring SSEPs
0.5% or less MAC for inhaled, narcotic-based, or TIVA
Nitrous oxide potentiates the depressant effects of inhalation agents
No ketamine or etomidate → can cause changes in amplitude and latency
Paralytic agents do NOT affect SSEP monitoring and can improve readings by minimizing skeletal muscle interference.
What are the BIS values and relation to anesthetic depth
0 = flat EEG
<40 = deep hypnotic state
40-60 = adequate anesthesia
100 = fully awake - following commands
