Monitoring Depth of Anesthesia Flashcards
What is DOA?
Depth of anesthesia
In what situations can pt awareness occur? (3)
Trauma
Cardiac surgery
Cesarean section
New brain wave monitoring can be helpful in reducing the risk of awareness, but what is the caveat?
They need to undergo rigorous scientific review process .
A highly trained anesthesia professional should be involved in your surgery. No technology can replace this. True or false?
True damnit.
At the present time, technologies for monitoring awareness has been perfected. True or false?
False
Stated by the ASA and AANA
What does this symbol represent?
American Society of Anesthesiologists
What does our future logo look like?
Kaduceus is depicted on our our logo. He has wings. He must drink Red Bull.
Who do we swear oath to?
Apollo the physician
Where do people that have crappy anesthesia go to after their traumatic surgery?
Post-traumatic Stress Disorder Clinic
If a person experienced an event that threatens the physical integrity of self or others, what does the response include?
Fear, helplessness, and horror
In children, agitation or disorganized behavior
How is the traumatic event persistently reexperienced? (5)
- Recurrent and intrusive distressing recollections of the event
- Recurrent distressing dreams of the event
- Acting or feeling as if the traumatic event were recurring
- Intense pyschological distress at exposure to cues
- Physiologic reactivity on exposure to internal or external cues
___ of ___ patients with awareness had no postoperative sequelae.
8 of 26
Guedels phsyical signs of ____ anesthesia and involved ocular movements, pupils, and eye reflexes.
What drug introduced in the 1940s changed the emphasis from too-deep to too-light anesthesia?
ether
curare
What are the goals of a satisfactory anesthetic? (3)
Adequate perfusion of all organ systems
Unresponsive to noxious stimuli
No awareness or recall of events during the procedure
Conscious awareness during general anesthesia occurs most commonly in what procedures?
General surgery, NOT obstetric
What is the breakdown of causes of awareness?
Faulty anesthetic technique (70%)
Failure to check equipment (20%)
What are poor indicators of consciousness? (3)
Subcortical phenomenon
Movement (cord reflex)
Hemodynamic responsis (HR, BP)
Brainstem
The depth of anesthesia can be defined by suppression of what responses to noxious stimuli? (4)
Movement
Panting
Increased HR, BP
Sweating
What is an agent that quiets or calms the patient without affecting the clarity of consciousness?
What is an agent that allays excitement and produces a calm state?
tranquilizer
sedative
What autonomic indicators of anesthetic depth may be unreliable, but we use anyway? (6)
HR
BP
Pulse amplitude
Sweating
Tearing
Mydriasis
What tools can monitor anesthetic depth? (5)
- EEG (spectral edge, BIS, entropy)
- BAEP (brainstem auditory evoked potentials)
- Lower esophageal contractility
- Skin conductance measure sweating
- EMG (electromyography)
What responses to stimuli are first to go? (10)
- Verbal
- Implicit memory (previous experiences aid without conscious awareness)
- Explicit memory (intentional recollection)
- Purposeful movement
- Involuntary movement
- Ventilation
- Tearing
- Sweating
- BP
- HR
How much more stimulating is laryngoscopy than skin incision?
10 times more
What knowledge is easily recalled and explained?
explicit
What can we not consciously recall and it influences our behavior?
implicit
How much more alfentanil is needed for tracheal intubation than for skin incision?
about 2 times more
Label
At what concentration of iso will produce no movement during laryngoscopy?
At what concentration of iso will produce no movement during intubation?
- 8%
- 2%
What are methods of assessing anesthetic depth? (6)
- Clinical signs/isolated arm
- Dose of anesthetic
- Lower esophageal contractility
- Frontalis EMG (BIS which is an entropy device)
- Hear rate variability
- EEG
Most anesthesiolgists rely on what to assess anesthetic depth?
Clinical experience and dose of anesthetic
What does the isolated arm method involve?
Isolating the forearm with blood pressure cuff inflated above arterial pressure.
Induction with neuromusclar blockade then induced using opposite arm.
If pt is conscious, he can respond by squeezing the isolated hand and are usually free of pain, have no signs of awareness, and don’t remember being awake.
Developed by obstetric and now controversial.
What defines MAC?
ED50 which is not an inherently useful number.
Doses minimally larger than ED50 typically prevent movement.
Concentration-response relation for inhaled anesthetics is steep. True or false?
True, ie. ED95 differed minimally from ED50
The endpoint for MAC is mediated at subcortical levels. True or false?
True.
Thus, since the cortex is more sensitive the MAC is a higher concentration than is really needed. Removal of the cortex does not change MAC, and the concentration of anesthetic needed to cause unconsciousness is much lower.
What factors decrease MAC?
Hypothermia
Severe hypotension
Advanced age
Opioids
Chronic amphetamine
Anticholinesterases
Pregnancy
Hypoxemia
Anemia
A2 agonists