Arterial Blood Gas Analysis Flashcards Preview

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Flashcards in Arterial Blood Gas Analysis Deck (32):
1

Do acidosis and alkalosis pertain to the pH?

NO (ex. you can have a metabolic acidosis with a very high pH; higher than 7.4).

2

What is acidosis?

a process of either an increase in PCO2 or a decrease in the HCO3- that tends to lower pH.

3

What is alkalosis?

a process of either a decrease in PCO2 or an increase in the HCO3- that tends to raise pH.

4

What is acidemia?

a decrease in blood pH (less than 7.4)

5

What is alkalemia?

an increase in blood pH (greater than 7.4)

6

What is normal PCO2?

40

7

What is normal HCO3-?

24

8

What do you have if your pCO2 is less than 40?

respiratory alkalosis

9

What do you have if your pCO2 is greater than 40?

respiratory acidosis

10

What do you have if your HCO3- is greater than 24?

metabolic alkalosis

11

What do you have if your HCO3- is less than 24?

metabolic acidosis

12

**** What are the 3 rules of acid/base?

1. Ignore the pH. Read the pCO2 and the HCO3-
2. The pH points toward the primary process (if 7.4 then there are 2 primary processes).
3. Use the compensation formula (Winter's or ratios) of the primary process.

13

Will compensation ever completely normalize an acid/base disturbance?

NO!

14

What must we always define when we calculate for compensation?

if it is appropriate or not.

15

Does it take the kidneys a long time to compensate for a respiratory acid/base disturbance?

YES

16

*** What is the respiratory compensatory response for a metabolic acidosis (decrease in HCO3-)?

a DECREASE of 1.2 mmHg in pCO2 in the blood for every 1 meq/L fall in HCO3- (so you are trying to blow off more CO2

17

*** What is the respiratory compensatory response for a metabolic alkalosis (increase in HCO3-)?

an INCREASE of 0.7 mmHg in pCO2 in the blood for every 1 meq/L rise in HCO3- (so you are trying to keep more CO2 in the lungs to balance the pH).

18

*** What is the metabolic compensatory response for an ACUTE respiratory acidosis (increase in blood pCO2)?

an INCREASE of 1 meg/L in HCO3- for every 10 mmHg rise in pCO2.

19

*** What is the metabolic compensatory response for a CHRONIC respiratory acidosis (increase in blood pCO2)?

an INCREASE of 3.5 meg/L in HCO3- for every 10 mmHg rise in pCO2.

20

*** What is the metabolic compensatory response for an ACUTE respiratory alkalosis (decrease in blood pCO2)?

a DECREASE of 2 meg/L in HCO3- for every 10 mmHg fall in pCO2.

21

*** What is the metabolic compensatory response for a CHRONIC respiratory alkalosis (decrease in blood pCO2)?

a DECREASE of 4 meg/L in HCO3- for every 10 mmHg fall in pCO2.

22

**** SEE QUESTION EXAMPLES IN NOTES

**** SEE QUESTION EXAMPLES IN NOTES

23

What 3 of the 4 diagnoses do not require further investigation once they are made?

1. respiratory acidosis
2. respiratory alkalosis
3. metabolic alkalosis

24

**** What diagnosis requires further investigation (as Venditto says, it comes in vanilla, chocolate, and strawberry)?

metabolic acidosis!!
- increased anion gap
- normal anion gap
- decreased anion gap

25

How are the electrolytes written?

Na+ / Cl-
K+ / total CO2

26

** What is the total CO2?

HCO3- + (pCO2 x 0.03)
*SO it is really only adding about 1 to the HCO3- and this is why most people say bicarb.

27

What is the anion gap?

difference between the cations and the anions.
*normal is about 10

28

What are the pneumonics for gapped vs normal metabolic acidoses?
(picmonic)

- gapped (increased)= MUDPILES (still not done...)
- normal= HARD UP (and you're done)
- non-gapped (decreased; not the same as normal)= BMW and you're done; bromide toxicity, multiple myeloma (increased IgG), waldestoms (increased IgM).

29

Where can you see bromide toxicity?

someone who ingests hot tub water by accident because you keep them clean with bromide rather than chlorine because the heat of the hot tub denatures the chlorine.

30

**** Since you're still not done following a gapped metabolic acidosis, what else do you have to do?

- delta/delta, which is the (delta anion gap/delta HCO3-)
to calculate for additional acid/base disturbance.
*If 2= increased gap + metabolic alkalosis
*If between 1 and 2= increased gap only

31

**** What is the difference between pO2 and O2 saturation?

- pO2= the oxygen dissolved in plasma (where the actual diffusion happens).
- O2 saturation= the oxygen in the RBC (where most of the O2 is, and is required to maintain the pO2).

32

How much pO2 do you get for a given O2 sat?

the body adjusts in amount of pO2 to its surroundings (shifts the O2 dissociation curve left or right).
*Ex. you'll get a higher pO2 for a given amount of O2 saturation when you're running a temperature (fever).