Lecture 04_Fall Flashcards
What does the Meyer-Overton Rule state?
Potency correlates with lipid solubility
T or F. Partial pressures are additive?
TRUE
____ is the amount of gas dissolved in a solution.
Concentration
___ = volume of gas / volume of liquid
solubility
Gases equilibrate based on ___, not based on ___.
Partial Pressure, not concentrations
T or F. Fractional concentration (F) is equal to partial pressure (P)?
TRUE
Which three areas of the brain are responsible for the amnesia caused by GA?
hippocampus, amygdala, temporal lobe
T or F. Inhalational anesthetics are gases that are rapidly transferred bidirectionally via the lungs to and from the bloodstream and subsequently to and from the tissues of the CNS as partial pressures equiliberate?
TRUE
A gas with high solubility will have a partition coefficient _ 1? (is it >,<, or =)
A gas with high solubility will have a partition coefficient > = 1
What determines how much gas can dissolve in a given solution?
The solubility coefficient / partition coefficient
An ideal anesthetic gas has a higher or lower solubility?
You want low solubility. With low solubility, you have less agent in the blood and more in the gas phase. You need to dissolve less gas in order to generate a certain partial pressure
A fast induction is defined as __/__ –> ___ quickly.
FA / FI –> 1 quickly
Put the following in order from fastest to slowest for rate of induction: Iso, Sevo, Halothane, N20, Des
N2O, Des, Sevo, Iso, Halo
What is the blood:gas partition coefficient for halothane?
2.4
What is the blood:gas partition coefficient for N2O?
0.47
Non-soluble agents leave the lungs fast/slow which leads to faster induction.
slow
Uptake = agent moving from ___ –> ____.
Lungs to blood
high uptake leads to __ induction
slow
T or F. A large gradient between the agent in the blood and the agent in the lungs leads to a faster induction.
False. A small gradient means that uptake will be low and induction will be fast.
What does uptake depend on?
agents solubility, cardiac output, and the difference in partial pressure of the anesthetic agent in the alveoli and pulmonary blood
Cardiac output functions as a ____ feedback loop for induction.
Cardiac output functions as a positive feedback loop. Low CO –> rapid induction –> lower CO…Positive Feedback Loop
What factors effect the speed of induction?
Uptake (Solubility x CO X (Palveoli - Pvenous))VentilationConcentration
Ventilation acts as ____ feedback loop for induction.
high vent -> rapid induction -> lower ventilation…negative feedback loop
As ventilation increases, rate of induction ____.
Increases
The ____ Effect explains why N2O has a faster induction rate than Desflurane.
The Concentration Effect (“Overpressurization”)
T or F. Induction is faster with N20 than Desflurane because N20 is less soluble than Desflurane.
False. Even though Des is less soluble than N2O, induction is faster with N2O because the inhaled concentration of N2O is greater than the concentration of Des.
T or F. The Concentration Effect is seen with induction using N2O with another anesthetic gas - when N2O gets absorbed, the other gas is concentrated and FA increases leading to a faster induction rate.
False. This is called The Second Gas Effect
T or F. A V/Q mismatch would explain why Fa does not = FA.
TRUE
T or F. There is no metabolism of inhalational anesthetics. They are eliminated through the lungs during exhalation.
False. There is some metabolism seen with halothane and methoxyflurane
If you are using N2O and extubate to room air, the patient could experience ______ as N2O floods the alveolus and dilutes the oxygen.
diffusion hypoxia
