Blood Gases

Question 1

Tube type used for blood gases.

Answer 1

Heparinized, plastic syringe.

Question 2

What type of sample (anaerobic/aerobic) is needed for pH and blood gas studies?

Answer 2

Anaerobic.

Question 3

How will CO2, pH, and O2 be affected by an opened sample?

Answer 3

↑ pH
↑ O2
↓ CO2 and pCO2

Question 4

How will CO2, pH, and O2 be affected by the sample not being put on ice right away?

Answer 4

↑ CO2
↓ pH
↓ O2

Question 5

In metabolic acidosis, the primary gas in deficit is..

Answer 5

HCO3.

Question 6

What conditions could cause metabolic acidosis to occur?

Answer 6

DKA, renal disease, diarrhea, late salicylate poisoning.

Question 7

In metabolic acidosis, what are the compensatory mechanisms used for the lungs and kidneys?

Answer 7

Primarily respiratory
   - Hyperventilation
   - ↓pCO2
Some renal
   - ↑ excretion of H
   - Reabsorption of HCO3

Question 8

What are common lab findings for metabolic acidosis?

Answer 8

↑pH, HCO3, CO2, and pCO2; acidic urine.

Question 9

In metabolic alkalosis, there is an excess of ___.

Answer 9

Bicarbonate (HCO3).

Question 10

Metabolic alkalosis is seen in what conditions?

Answer 10

Vomiting, K depletion, diuretic therapy, and Cushing’s Syndrome.

Question 11

What types of respiratory compensatory mechanisms are used for a patient in metabolic alkalosis?

Answer 11

Primarily respiratory: hypoventilation, ↑ retention of CO2.

Question 12

What types of renal compensatory mechanisms are used for a patient in metabolic alkalosis?

Answer 12

Some renal: ↓ excretion of H; ↑ excretion of HCO3.

Question 13

What are common lab findings for a patient in metabolic alkalosis?

Answer 13

↑ pH, HCO3, CO2, and pCO2.

Question 14

In respiratory acidosis, patients primarily have excess ___.

Answer 14

CO2.

Question 15

Respiratory acidosis is seen in what conditions?

Answer 15

Emphysema, pneumonia, and rebreathing air (paper bag).

Question 16

What renal compensatory mechanisms are used for a patient in respiratory acidosis?

Answer 16

↑ H excretion; HCO3 reabsorption.

Question 17

What are common lab findings in patients with respiratory acidosis?

Answer 17

↓ pH, and ↑ HCO3, CO2, and pCO2.

Question 18

For a patient in respiratory alkalosis, the primary deficit is ___.

Answer 18

CO2.

Question 19

Respiratory alkalosis is commonly seen in what conditions?

Answer 19

Hyperventilation and early salicylate poisoning.

Question 20

What renal compensatory mechanisms are used for a patient in respiratory alkalosis?

Answer 20

↓ H excretion.

Question 21

What are common lab findings in patients with respiratory alkalosis?

Answer 21

↑ pH and HCO3; ↓ pCO2 and CO2.

Question 22

If pCO2 is opposite of pH, it is a likely indication of…

Answer 22

respiratory condition.

Question 23

If HCO3 and pH are going in the same direction, it is likely an indication of…

Answer 23

metabolic condition.

Question 24

When a patient has known alkalosis/acidosis and the pH returns to normal, what is likely the cause?

Answer 24

Full compensation occured.

Question 25

If main compensatory mechanism kicked in, but pH is still out of normal range, what likely occurred?

Answer 25

Partial compensation occured.

Question 26

Primary respiratory dysfunction results in change in ___ (seesaw); main compensation is HCO3 (metabolic).

Answer 26

pCO2.

Question 27

Primary metabolic dysfunction results in change in ___ (swing); main compensation is pCO2 (respiratory).

Answer 27

HCO3.

Question 28

Define Base Excess/Deficit.

Answer 28

Defined as the amount (dose) of acid/base needed to return pH to normal.

Question 29

What two blood gasses are used to determine the Base Excess/Deficit calculation?

Answer 29

pH and pCO2.

Question 30

A positive base excess (↑pH) is an indication of…

Answer 30

Metabolic alkalosis.

Question 31

A negative base excess (↓pH) is an indication of…

Answer 31

metabolic acidosis.

Question 32

pH reference range.

Answer 32

7.35 - 7.45.

Question 33

pCO2 reference range.

Answer 33

35 - 45 mmHg.

Question 34

HCO3 reference range.

Answer 34

22 - 26 mmol/L.

Question 35

pO2 reference range.

Answer 35

85 - 105 mmHg.