Blood Gas Analysis Flashcards Preview

Anesthesiology > Blood Gas Analysis > Flashcards

Flashcards in Blood Gas Analysis Deck (41):
1

T/F: H+ is constantly being produced by metabolism.

True

2

What organs are involved in acid-base homeostasis?

Lungs, Kidney, Liver, GIT

3

What are the chemical buffers in the body?

Extracellular: HCO3-
Intracellular: Phosphate, proteins (slower acting)

4

How long does renal compensation take?

Hours to days

5

How long does respiratory compensation take?

Minutes (increase or decrease RR)

6

What are measured in Blood gas analysis?

-pH
-PaCO2
-PaO2

7

What are calculated in blood gas analysis?

-HCO3-
-BE
-O2 content (CaO2)

8

What is assessed for respiratory component?

PaCO2

9

What is assessed for metabolic component?

BE or HCO3

10

Normal pH

7.35-7.45

11

Normal HCO3-

24+/-4 mEq/L

12

Normal PaCO2

35-45 mmHg

13

Herbivores produce more......

HCO3-

14

Normal Cat values

HCO3- ~20mEq
PsCO2 ~30mmHg

15

Base Excess

Refers to an excess or deficit in the amount of base present in the blood

The differene of HCO3- from normal value if PaCO2 and temp were normalized

16

Positive Base excess

Metabolic alkalosis

17

Negative Base excess

Metabolic acidosis

aka base deficit

18

Anion Gap

The amount of positive and negative ions should be equal, the difference is represented in unmeasured ions

19

Main positive ions

Na and K

20

Main negative ions

Cl and HCO3

21

Normal Anion Gap

16+/-4 mEq/L

22

What causes elevated AG?

Metabolic acidosis (KLUE)

Ketoacidosis
Lactic acidosis
Uremia
Ethylene glycol or other toxins/drugs

23

Metabolic acidosis with a normal AG?

May be due to Cl retention or HCO3 excretion

Diarrhea or renal disease

24

Total CO2 is a measurement of?

HCO3- and dissolved CO2

25

Is TCO2 an accurate measurement of HCO3?

Yes, dissolved CO2 is only a small amount

26

T/F: Results of blood gas should be interpreted with physical exam, lab work, etc.

True

27

PaCO2 is ____ related to CO2 production and _____ related to CO2 elimination

Directly; indirectly

28

Results of PaCO2

1. Lower the PaO2
2. Lower the pH
3. Reflect respiratory acidosis
4. Reflect respiratory compensation for metabolic alkalosis

29

Does PaO2 reflect O2 content?

No

30

Is PaO2 or PAO2 lower?

PaO2 is always lower

31

Reason for high A-a difference

V/Q mismatch
Right to left shunt
Diffusion impairment (not vet med)

32

Reasons for V/Q mismatch

Atelectasis
Lung diseases

33

PaO2/FiO2 ratio

Serves same purpose as A-a gradient but easier to interpret

34

Normal PaO2/FiO2 ratio

>500mmHg

35

Hypoxemia

Insufficient oxygenation of arterial blood

SpO2

36

5 Causes of Hypoxemia

1. Low FiO2
2. Hypoventilation
3. Diffusion impairment
4. V/Q mismatch
5. Right to left shunt

37

A-a PO2 has been used to distinguish what?

Lung disease from hypoventilation as a cause of hypoxemia

38

Under anesthesia, what is A-a PO2 difference used to diagnose?

V/Q mismatch resulting from pulmonary atelectasis

39

Hypoxemia with normar PaO2

Anemia or pathological Hb

40

Hypoxia

Insufficient oxygenation of the tissues

41

Causes of hypoxia

1. Hypoxemia
2. Insufficient tissue perfusion
3. Insufficient uptake of O2 by cells