inhaled 2

Question 1

decreased rate of rise of FA/FI means

Answer 1

slower induction

Question 2

what causes a decreased rate of FA/FI

Answer 2

increased CO, increased FRC, decreased fresh gas flow. (think slow wash in and fast uptake)

Question 3

increased rate of rise of FA/FI means

Answer 3

faster induction

Question 4

what causes an increased rate of FA/FI

Answer 4

decreased time constant, decreased anatomic dead space, increased alveolar ventilation (think fast wash in and slow uptake)

Question 5

what is the Fi

Answer 5

inspired gas concentration

Question 6

Fi (inspired gas concentration) is determined by

Answer 6

FGF rate, breathing circuit volume, and circuit absorption

Question 7

FA (alveolar gas concentration) is determined by

Answer 7

uptake, ventilation, and the concentration effect and second gas effect

Question 8

concentration effect has to do with how gases travel from ___ to ___

Answer 8

lungs,blood

Question 9

how does the concentration effect promote the rapid induction in anesthesia

Answer 9

the higher the concentration of anesthetic agent delivered, the faster the anesthesia is achieved- ↑inspired volumes => ↑ alveolar partial pressure (PA) and so on..

PA = Pa = Pbr

Question 10

higher concentrations —> ____ uptake

Answer 10

greater/faster

↑partial pressure difference

Question 11

the rate at which the alveolar pressure of the anesthetic rises is determined by what 2 factors?

Answer 11

1) inspired concentration (what you turn your dial to- ↑=faster)
2) alveolar ventilation (how often/how much you are ventilating the alveoli- hyperventilate= faster)

Question 12

the faster you replenish the concentration in the alveoli, the ___ the induction

Answer 12

faster

Question 13

Second Gas Effect

Answer 13

the rapid crossing of N20 into the blood is faster than N leaving (N20 34x more soluble) => alveoli shrink = ↑ 2nd gas PA, this also tends to pull the second gas along with it => Pa pressure of the 2nd gas rises more rapidly than it would if it were alone in the alveoli.

Question 14

3 factors determine how rapidly anesthetics pass from the inspired gas to the blood:

Answer 14

1) solubility of the agent
2) rate blood flow thru the lungs (CO)
3) Partial pressure of the agents in the arterial/venous blood (Pa)(whatever is in the blood already)

Question 15

the blood:gas partition coefficient represents what?

Answer 15

Solubility!
At equilibrium:
concentration in the blood to anesthetic concentration in a gas (alveolar) (Pa/PA)

Question 16

CO - The higher the blood flow, the more blood that is exposed to the agent, the ___ the agent is picked up from the alveoli and delivered to the tissues

Answer 16

faster

Question 17

as the venous partial pressure rises, there Is ___ picked up from the alveoli and uptake _____

Answer 17

less, decreases. (think: the gradient is less as tissues are becoming saturated and the venous blood returning has a higher partial pressure.)

Question 18

solubility of the gas in tissues is which coefficient

Answer 18

oil:gas

Question 19

the higher the blood flow to a particular tissue, the ___ the anesthetic is delivered and the ___ the partial pressure and concentration will rise in that area

Answer 19

faster, faster

Question 20

the rate at which the partial pressure in the blood and tissues equalize is determinedly 2 things:

Answer 20

solubility of gas in tissues and tissue blood flow.

Question 21

The rise in alveolar (FA) anesthetic concentration toward the inspired (Fi) concentration is most rapid with the ___ soluble agents

Answer 21

least. nitrous is fastest. (it has to do with the amt that can be dissolved in the blood)

Question 22

the moderately soluble anesthetic agents (such as iso) have a ___ rate of Fa to Fi rise

Answer 22

slower (think this is why we use nitrous for the second gas effect, because these gases are slow, bc they have a higher blood:gas coefficient)

Question 23

the higher the blood:gas coefficient, the ___the uptake

Answer 23

slower