Flashcards in Uptake & Distribution Deck (21)
We use ______ ________ to move our product.
Fraction of DELIVERED gas (percentage in the flow as it leaves the machine)
Fraction of INSPIRED gas (the percentage as the patient ventilates)
Fraction of ALVEOLAR gas (percentage in the alveoli; most closely reflects the concentration in the brain)
What is our end-target organ with inhaled anesthetics?
Which anesthetic has the GREATEST uptake?
The one with the highest blood solubility; It piles up on the Blood Train when it leaves the Lung Station because it loves that fucking train! (HALOTHANE)
Which anesthetic has the FASTEST uptake?
The one with the lowest blood solubility, meaning it jumps off the Blood Train when it reaches the Brain Central Station because it hates to be on that damn train. (DESFLURANE)
What characteristic determines the rise of Fa?
Solubility (inverse relationship; most soluble raises Fa the slowest, and vice versa...)
What are some factors that can speed up an inhalation induction?
- Low blood solubility
- Increased Fi of anesthetic
- Increased Vital capacity and Ventilation
- Less distribution to peripheral compartment
- Decreased CO (slower train means more chemical passengers can jump on that shit)
What are some nifty factors that slow awakening?
- High tissue solubility
- Long anesthetic times
- Low gas flows
- Increased Cardiac Output
What the heck is a time constant?
1 TC exchanges 63%
2 TC exchanges 86%
3 TC exchanges 95%
4 TC exchanges 98%
TC for the lungs is approx. 30 seconds!
Effect of ventilation on speed on anesthetic on or off?
Direct proportional relationship (The faster they ventilate, the faster the anesthetic goes on or off)
Effect of CO on anesthetic?
Inverse relationship (The lower the CO (to a point...), the more inhaled anesthetic can make it into the bloodstream to then make its way to brain, like trying to jump on a moving train. If the train is moving faster, it's harder to jump on)
What are the 4 main groups of tissues we concern ourselves with?
Vessel-rich, muscle, fat, vessel-poor
What is the % of body mass/% CO received of the vessel-rich group?
What is the % of body mass/% CO received of the muscle group?
What is the % of body mass/% CO received of the fat group?
What is the % of body mass/% CO received of the vessel-poor group?
In what order do the groups equilibrate?
Let's think about the concentration effect (overpressurinzing) for a second. What is its significance?
By increasing the Fd, the Fa can reach desired concentrations faster.