Inhaled Anesthetics 2 Flashcards
Ideal Anesthetic:
- Pharmacokinetics unaltered by ___.
- High degree of ___.
- Levels easily identified and managed, ___ adjustment of depth of anesthesia.
- Wide ___.
- Rapid ___ and ___
- patient pathophysiology
- specific action/function
- rapid
- margin of safety
- induction and recovery
Ideal Anesthetic: -Easy to administer. -No unwanted effects on organs.
- Controllable ___.
- No ___.
- Predictable ___.
- Useful in all age groups.
- Adequate ___.
- duration of action
- toxic metabolites
- elimination
- muscle relaxation
Theories of Anesthesia: NO SINGLE UNIFYING THEORY
- State of unconsciousness of the brain (hypnosis and sedation) plus immobility to noxious stimuli?
- Assumed sites of action?
- Observations of ___ supports the theory that a (mysterious) specific protein receptor interaction “target molecule” is involved.
- General anesthesia
- CNS (brain/spinal cord)
- stereoselectivity
-Theory: GA inhibits excitatory postsynaptic potentials (amino acids ___ and ___) and/or promote inhibitory actions of ___ and ___.
- ___ = all GA act by the same mechanism
- ___ = different classes = different mechanisms
Glutamate and aspartate
GABA and Glycine
*Unitary Theory
*Degenerated Theory
Various Theories Explaining Anesthetic Site of Action:
___ = absorption of anesthetic molecules expands hydrophobic region-expansion of lipid bilayer beyond critical amount and alters membrane function.
Critical Volume-Meyer Overton Theory
Action in the brain has been attributed to ___ stimulation causes chlorine influx to hyperpolarize the membrane so then it is non-responsive.
In the spinal cord believed to be in the ventral horn stimulation of ___, inhibition of the ___ and inhibition of the ___ (theory).
GABA-A receptor
glycine molecules
NMDA receptors
sodium channels
Triad of Anesthesia:
1) ___ occurs in ???
2) ___ occurring in the ??
3) ___ occurs in the ?
1) unconsciousness cerebral cortex, thalamus, RAS 2) amnesia amygdala, hippocampus 3) immobility spinal cord-ventral horn
Various Theories Explaining Anesthetic Site of Action:
___ = binding modified membrane structures, alters conductance, conformation change in channels.
Fluidization Theory
Various Theories Explaining Anesthetic Site of Action:
___ = Correlation btw potency and lipid solubility.
Lipid Theory
Various Theories Explaining Anesthetic Site of Action:
___ = anesthetic displaces lipids necessary for protein function.
Protein/Lipid Interface
Various Theories Explaining Anesthetic Site of Action:
___ = -anes occupies receptor site.
(act on neuronal membrane proteins that permit ionic conductance during membrane excitation)
Protein Receptor Theory
Agents potency is determined by its affinity for lipid tissue?
Critical Volume-Meyer Overton Theory
Stages of Anesthesia - Geudel: 4 stages????
- Created when anesthetics were done with ether - inhalational agents may not see all of these stages except with a pediatric induction.
- Focus on Stage 1 and Stage 2. Stage 1 child much calmer, generally go for the IV at this stage. Stage 2 (get parents out of room beforehand) child goes into delirium and excitement, need to hold the child down. May give some ___ to counteract. But for fast procedures will go through these 2 stages.
1-amnesia/analgesia 2-delirium/excitement 3-surgical anesthesia, 4 planes 4-overdose -opioid or propofol
The fourth level of consciousness of stage 3 is demonstrated by cardiovascular impairment that results from ___. If this plane is not corrected immediately, ___ quickly ensues.
diaphragmatic paralysis
Stage 4
Induction - dial set at 8/9 = overpressurization
because it has a very high VP which approaches atmospheric pressure, requires a special vaporizer (heated vaporizer). This is at sea level, in Denver real close!!!!
Desflurane (664)
Modern Anesthetics:
Combining carbon with ___ decreased flammability lead to creation of first halogenated hydrocarbon anesthetic ___ - withdrawn from market due to ___.
Fluorine
Fluroxene
Organ toxicity
First ideal anesthetic?
- easy to make in pure form, easy to administer, liquid at room temp but readily vaporized, potent anesthetic (few drops needed, produce anesthesia without diluting oxygen to hypoxic levels), supports respiration and circulation, not toxic to vital organs.
- Downside?
Ether
*flammable
Pleasant odor, nonflammable, severe cardiovascular depressant, high incidence of intra and postop deaths, difficult to administer?
*Major downside?
Chloroform
*known hepatotoxin
The pressure created when gas molecules bombard the surface of a liquid and the walls in a closed container?
Vapor pressure
When Vapor pressure equals Barometric pressure?
Boiling Point
Molecules of a volatile agent in a closed container are distributed btw the ??
liquid and gas phases
Great induction drug for pediatric anesthetics
and it is really cheap. But not used as much?
Type?
Halothane (Fluothane)
halogenated alkane derivative
This is most commonly administered with induction agent, opioids, volatile agents, skeletal muscle relaxant?
This is known as?
Nitrous oxide
Balanced Technique
