Spirometry and ABGs

Question 1

What is a normal FEV1/FVC ratio?

Answer 1

> 75%

Question 2

Describe the FVC, FEV1 and ratio in an obstructive disease pattern

Answer 2

FVC = normal
FEV1 = low
ratio = low

Question 3

Describe the FVC, FEV1 and ratio in a restrictive disease pattern

Answer 3

FVC = low
FEV1 = low
ratio = normal

Question 4

How does the body attempt to compensate for changes in pH?

Answer 4

Lose or gain CO2 (acid) through changing RR –> rapid

Lose of gain bicarbonate (alkali) through the kidneys –> slow

Question 5

If the change in pH is due to a respiratory cause, how will the pH relate to the CO2?

Answer 5

Opposite:
low pH, high CO2 –> respiratory acidosis
high pH, low CO2 –> respiratory alkalosis

Question 6

What are the features of a metabolic acidosis?

Answer 6

Increased H+ produced by body –>
low pH
low CO2 due to increased RR (body trying to get rid of CO2)

Question 7

What are the features of a metabolic alkalosis?

Answer 7

Loss of acid from body e.g. vomiting
High pH
Low RR to retain CO2 (acid)
Slightly elevated CO2

Question 8

What are some causes of a respiratory alkalosis?

Answer 8

Anxiety, sepsis, pain (hyperventilation)

Question 9

What are the features of a respiratory alkalosis?

Answer 9

High pH
High RR
Low CO2