Entropy Monitoring Flashcards
What is Entropy?
It uses EEG and FEMG signals to determine the CNS state during anesthesia.
How is entropy measured?
It measures the cortical electrical activity via EEG which becomes more regular with deeper anesthesia and FEMG quiets down as anesthetic is deepened.
FEMG stands for?
Frontalis Electromyography
BIS monitoring does what?
Monitors the effect of anesthetics in the brain
Do you have to calibrate the BIS monitor?
NO
Do the drugs given effect the patient and how they are monitored?
No they are independent of each other
What are the 3 parts to the anesthesia triad?
Consciousness/Hipnosis, Analgesia, Muscle Realxation
How do we measure how well we are managing analgesia for our patients?
Autonomic and Somatic Responses
How do we evaluate how well our patients are muscle relaxed?
Train of 4
How can we monitor our patients Consciousness?
BIS monitor
BIS Range Guidelines: 0 - 39?
Deep hypnotic state, EEG supression
BIS Range Guidelines: 40 - 60?
Moderate Hypnotic State
BIS Range Guidelines: 61 - 70?
Light Hypnotic State
BIS Range Guidelines: 71 - 100?
Awake, Light to Moderate Sedation
BIS numbers less then what have a low probability of consciousness?
60
BIS numbers less then what have a low probability of recall?
70
Benefits of entropy monitoring?
Less drug utilization, faster wake up and extubation, More alert in PACU, Reduced PONV
Estimated population aware during anesthesia?
1:1000
Optimal Depth of Unconsciousness?
40-60 on the BIS
Most important Reason to use a BIS monitor?
Effective monitoring for risk of awareness
Can you use the BIS on the Left, RIght or both sides of the head?
Both
Placement of the BIS
Circle 1- centered above the nose 2 inches Circle 4- Above and adjacent to eyebrow Circle 3 - At the temple between the the corner of the eye and hairline
The SQI number from 0-100 is an ________ of _________ obtained in the last 60 seconds.
Average of information
The EMG may bias the BIS to a HIgher or Lower value?
Higher value
Name two categories of drugs that lower the EMG (muscle tone)?
Analgesics and Hypnotics
Name the 2 major sites that anesthetics work?
Brain and spinal cord
Is BIS an anesthetic depth measurement?
NO, it’s just one more piece of info on your patient to make a decision
Know The RANGES
BIS response to Ketamine administrtion is
Atypical
BIS response to anelgesia administration is dependent on
Level of stimulation
BIS monitoring derives brain status from the EEG not?
The concerntation of a particular drug
The BIS index valuse is calculated over how many seconds
15 -30 seconds
BIS values may lag behind observed clinical changes by how long?
5-10 seconds
EMG (forehead muscle tone) may increase or decrease BIS?
Increase
During stable anesthesia without EMG artifact, Neuro muscular Blockers have little or no effect on the BIS??
True or False
True
Ketamine may transiently increase BIS values due to EEG activation??
True or False
True
Etomidate may transiently increase BIS??
True or False
True related to the drug induce myoclonus
Which druge will increase the BIS value
Phenelphrine or Ephedrine
Ephedrine
Phenelephrine dose not
Beta blockers and Alpha 2 Blockerswill cause and increase in the BIS value??
True or False
False they will cause a decrease in the BIS value
If excessive EMG was noted on your patient prior to induction and a neuromuscular blocker was administered will ou have a steep incline or decline in the BIS value?
Steep decline because the BIS takes into account the EMG
On what types of patients should a BIS monitor be used on?
Previous episodes of awareness
High opoid sedative tolerance
Anticipated difficult airways
Known to be hemodynamically unstable
Surgical procedures with an increase risk of awareness
There has been shown an 80% reduction in incidents of awarness when using the BIS monitor
True or False
True
Is Entropy different then BIS
Yes Bis measures mainly EEG giving you one number while Entropy measures Frontalis electromyography and EEG changes
EEG patterns change from irrgeular to regular with anesthetic depth??
Ture or False
True
FEMG patterns increase with anesthetic depth
True or Flase
False the Frontalis electromyography quiets down as the brain is saturated with anesthetic
What does entropy measure?
The irregularity of the EEG and FEMG signals
There are 2 entropy parameters what are they?
Response Entropy
and
State Entropy
Response Entropy (RE) is sensitive to what?
facial muscle activation with in 2 seconds
State Entropy (SE) is always less than or equal to what?
Response Entropy (RE)
State Entropy is base on what?
The EEG signal
Do NMB effect the EEG?
NO
Are the BIS and Entorpy guidline ranges the same for conciousness?
YES
40-60 is where you want to be for no recall
Entropy and BIS will help the CRNA with what?
Ensuring faster and more predictable wake ups
Improving drug management
Avoid unnecessary deep anesthesia
prevent unexpected recovery
What infulences the probability of awarness druing surgery?
ASA class 3-5
High opoid tolerence
What is the % of awake anesthetics in the US?
1-2 per 1000
BIS reduces PONV by how much in ambulatory surgery
50%
Does BIS reduce PACU stay?
Yes by 16%
Less then 40 on the concious guidlines for BIS or Entropy means what
Deep Hypnotic State
EEG suppression
What is the most critical component of the BIS / Entropy System
Dual position versitility or
right or left application
EMG may bias the BIS to a higher value
True or False
True
Reliance on the BIS for intraoperative anesthetic managment alnoe is recommended?
HELL NO !!!!!
