Arterial Blood Gas (ABG)

T/F: Gradual chronic changes are more dangerous than sudden, acute changes in blood pH, and and tend to be associated with more serious clinical manifestations

False (acute)

T/F: An ABG only gives you snapshot of what is happening at that exact moment in time

True

What system do you get an ABG from (arterial or venous)

Arterial ONLY

1 multiple choice option

What patients often benefit from the use of supplemental oxygen, especially during exertion

Patients with low oxygen saturations

What is the most accurate method of assessing a patient's oxygenation, and acid–base status?

Arterial Blood Draw

T/F: Current technology allows for continuous monitoring of a patient's status

False (does not)

Normal value & range: pH (2)

- 7.4

- 7.35-7.45

Normal value & range: PCO2 (2)

- 40

- 35-45

Normal value & range: PO2 (2)

- 97

- >80

Normal value & range: HCO3 (2)

- 24

-22-28

Normal range: PaCO2

35-45

PaO2: normal

80-100

PaO2: mild hypoxemia

70-80

PaO2: moderate hypoxemia

60-69

PaO2: severe hypoxemia

<60

What is the primary pH buffer system in the human body?

HCO3/CO2 chemical equilibrium system

What common household item does Nan think bicarbonate is like?

baking soda, it is a basic substance that will raise the pH of a solution

What drink does Nan think of when she thinks of CO2 (something acidic)

Soda

If you are increasing HCO3, it will raise the pH of the blood and make it more ___ , whereas if you decrease bicarbonate the blood will become more ___ (decreasing pH)

alkalotic, acidic

1 multiple choice option

HCO3 functions as an ___ substance

alkalotic

1 multiple choice option

Increases in HCO3 will make blood more...

alkalotic

1 multiple choice option

decreases in HCO3 will make blood more...

acidic

1 multiple choice option

CO2 functions as an ___ substance

acidic

1 multiple choice option

Increases in CO2 will make blood more...

acidic

1 multiple choice option

decreases in CO2 will make blood more...

alkalotic

1 multiple choice option

ACIDOSIS: pH less than what?

7.35

ACIDOSIS: Metabolic cause

decreased HCO3 in the blood

Decreased HCO3 in the blood can be d/t (3)

- Severe diarrhea

- Severe dehydration

- Prolonged lack of O2 from HF

ACIDOSIS: Respiratory cause

Buildup of CO2 in the blood

What can cause a buildup of CO2 in the blood

Hypoventilation

1 multiple choice option

What population/diseased population is prone to ↑ of CO2 in blood

COPD (obstructive lung disease)

ALKALOSIS: Metabolic cause

Increased HCO3 in the blood

What can cause an increased HCO3 in the blood (3)

- Prolonged vomiting

- Severe hypokalemia/low potassium

- Excessive use of diuretics

ALKALOSIS: Respiratory cause

Decreased CO2 in the blood

What can cause a decreased CO2 in the blood

- Hyperventilation

1 multiple choice option

When the respiratory system causes abnormal blood pH, the ___ system can attempt to regulate that pH.

Renal

1 multiple choice option

Renal compensation: In acidosis, the kidneys generate ___ and clear acid (to clear CO2)

Bicarbonate

1 multiple choice option

Renal compensation: In alkalosis, ___ HCO3 is reabsorbed by the kidneys, thus lowering the pH

Less

1 multiple choice option

When metabolic systems cause abnormal blood pH, the ___ system can attempt to regulate that pH by varying the respiratory rate

Respiratory

1 multiple choice option

Respiratory compensation: In acidosis, chemoreceptors sense the decreased pH, ___ rate and depth of breathing

Increase

1 multiple choice option

Respiratory compensation: In alkalosis, the breathing rate is ___

Decreased

1 multiple choice option

What causes what?: Step 1... what do you do

Check pH level

What causes what?: Step 2... what do you do

Check paCO2 and HCO3 levels

What causes what?: Step 3... what do you do

Determine if acid/base is respiratory or metabolic

How do determine if acid/base is respiratory or metabolic

The value trending in the same direction as the pH is the cause of the imbalance

Value trending in the same direction as the pH: paCO2

Respiratory

1 multiple choice option

Value trending in the same direction as the pH: HCO3

Metabolic

1 multiple choice option

What causes what?: Step 4... what do you do

Determine if compensations are present

Determine if compensations are present: if pH is normal

Fully compensated

Determine if compensations are present: partially compensated

If CO2 & HCO3 are trending in opposite directions, but pH is not normal, the body is attempting to compensate

What is happening??

pH= 7.48

PaCO2= 28

HCO3= 24

PaO2= 54

Non compensated respiratory alkalosis

What is happening??

pH: 7.84

CO2: 45

HCO3: 36

Metabolic alkalosis

What is happening??

pH: 7.1

CO2: 20

HCO3: 13

Partially compensated metabolic acidosis

Interpretation/what is happening?

FiO2 = .80 (w/ O2)

PaO2 = 79

PaCO2 = 40

pH = 7.33

HCO3 = 21

Metabolic acidosis, not compensated

FiO2: What is it and what is normal (2)

- Fraction of inspired oxygen

- Normal: 21%

Interpretation/what is happening?

FiO2 = .21 (w/ out O2)

PaO2 = 79

PaCO2 = 30

pH = 7.33

HCO3 = 20

Metabolic acidosis, partially compensated

Interpretation/what is happening?

FiO2 = 0.21 (w/ out O2)

PaO2 = 55

PaCO2 = 60

pH= 7.40

HCO3 = 31

Respiratory acidosis, fully compensated

Interpretation/what is happening?

pH=7.22

pCO2=57

HCO3=26

Respiratory acidosis, not compensated

Interpretation/what is happening?

pH=7.23

pCO2=54

HCO3=30

Respiratory acidosis, partially compensated

Interpretation/what is happening?

pH=7.58

pCO2=45

HCO3=35

Metabolic alkalosis, not compensated

Interpretation/what is happening?

pH=7.54

pCO2=23

HCO3=25

Respiratory alkalosis, not compensated

Interpretation/what is happening?

pH=7.29

pCO2=35

HCO3=16

Metabolic acidosis, not compensated

Interpretation/what is happening?

PH=7.6

pCO2=42

HCO3=35

Metabolic alkalosis, not compensated