Arterial Blood Gases

Question 1

what is an important component of the chemical buffering system that keeps the blood from becoming to acidic or basic?

Answer 1

bicarbonate (HCO3-)

Question 2

Mean pH

Answer 2

7.35-7.45

Question 3

mean PaCO2?

Answer 3

35-45 mmHg

Question 4

mean PaO2?

Answer 4

80-100 mmHg

Question 5

mean HCO3-? (bicarbonate)

Answer 5

22-26 mEq/L

Question 6

What are Eucapnia, hypocapnia, and Hypercapnia

Answer 6

Eucapnia: normal level of CO2 in arterial blood
Hypercapnia: elevated CO2 >45 mmHg
Hypocapnia: low level of CO2 in arterial blood <35

Question 7

What is hypoxemia, mild hypoxemia, moderate hypoxemia and sever hypoxemia?

Answer 7

Hypoxemia: low level of O2 <80 mmHg
Mild: 60-79
moderate: 40-59
severe: <40

Question 8

What two enzymes are leaked after an MI and when do their blood levels peak?

Answer 8

Creatine Phosphokinase (CK): peaks 12-24 hours after MI
Troponin: remains elevated for 5-7 days

Question 9

What is considered the “good” cholesterol?

Answer 9

HDL because it helps carry away LDL cholesterol reffered to as bad cholesterol since it is associated with the buildup of fatty plaques within arteries

Question 10

What is hematocrit and what does it mean if it is high/low?

Answer 10

Hematocrit is the percentage of red blood cells in total blood volume

Low: anemia, blood loss

High: dehydration or polycythemia vera (condition with overproduction of RBCS)

Question 11

Just go to page 410!

Answer 11

p. 410

Question 12

What does a PaCO2 <30 mmHg and PaCO2 > 50 mmHg indicate?

Answer 12

PaCO2 <30 mmHg indicates alveolar hyperventilation

PaCO2 >50 mmHg indicates alveolar hypoventilation, ventilatory failure

Question 13

How would you interpret the following?

1. PaCO2 > 45 mmHg and pH <7.4
2. PaCO2 > 45 mmHg and pH > 7.4
3. PaCO2 < 35 mmHg and pH >7.4
4. PaCO2 <35 mmHg and pH <7.4

Answer 13

1. respiratory acidosis
2. retention of CO2 to compensate for metabolic alkalosis
3. respiratory alkalosis
4. elimination of CO2 to compensate for metabolic acidosis

Question 14

What is the purpose of bicarbonate?

Answer 14

Bicarbonate (HCO3). Bicarbonate is a chemical (buffer) that keeps the pH of blood from becoming too acidic or too basic.

Question 15

How would you interpret the following?

1. HCO3- < 22 mEq/L and pH <7.40
2. HCO3- < 22 mEq/L and pH > 7.40
3. HCO3- >26 mEq/L and pH >7.40
4. HCO3- > 26 mEq/L and pH < 7.40

Answer 15

1. metabolic acidosis
2. renal compensation for respiratory alkalosis
   Renal compensation for respiratory alkalosis involves a decrease in HCO3 – reabsorption
3. metabolic alkalosis
4. renal compensation for respiratory acidosis
   Renal compensation of respiratory acidosis is by increased urinary excretion of hydrogen ions and resorption of HCO3−. (Hydrogen ions lower pH = more acidic)

Question 16

What does ROME stand for?

Answer 16

Respiratory Opposite

High pH Low PCO2 – Respiratory Alkalosis
Low pH High PCO2 – Respiratory Acidosis

Metabolic Eqaul

High pH High HCO3- - Metabolic Alkalosis
Low pH Low HCO3- - Metabolic Acidosis

Question 17

What does it mean if ROME doesn’t match up like it is suppose to?

Answer 17

Then it is a COMPENSATION for the other type of acidosis/alkalosis

Question 18

What is always the cause of metabolic vs respiratory acidosis/alkalosis?

Answer 18

Respiratory is always caused by level of CO2 but may have bicarbonate compensations

Metabolic is always caused by level of bicarb but may have CO2 compensations

Question 19

Why does high CO2 lead to a lower pH?

Why does high HCO3 lead to high pH?

Answer 19

CO2 reacts with water to form carbonic acid (pH of 4)

becuase bicarbonate has a pH of 8.4

ROME

Question 20

What is the equivalent SAO2 for the following with no shift in oxyhemoglobin curve?

1. mild hypoxemia: PaO2 60-79 mmHg
2. moderate hypoxemia: PaO2 40-59 mmHg
3. Severe hypoxemia: PaO2 < 40 mmHg

Answer 20

1. PaO2 60-70 mmHg SaO2 90-95%
2. PaO2 40-59 mmHg SaO2 60-90%
3. PaO2 <40 mmHg SaO2 <60%