Spirometry

Question 1

When/Why do you use Spirometry?

Answer 1

• Evaluate signs and symptoms
• Monitor disease (see if the disease progresses or not)
• Monitor drug effects (does the patient improve after treatment)
• Make sure a patient can survive thoracic surgery (ex: smoker with lung cancer, if ressect an area of the lung with a tumor may cure cancer, but now the patient has decreased lung function)

Question 2

What are on the axis of a Flow Volume Loop

Answer 2

Y- flow
X- Volume

Above the X axis: expiration
Below: inspiration

Question 3

Tidal volume

Answer 3

Amount of volume that comes in with normal breathing

Question 4

Total lung capacity

Answer 4

Maximum amount of air that fills the lungs.
Total amount you can blow out until RV + RV.
Includes RV, therefore cannot determine value with Spirometry.
However, the point is at 0 on X axis.

Question 5

Residual volume

Answer 5

Blow out until you can’t anymore.
There is still a remaining volume of air in the lung - residual volume.

Cannot determine this value with Spirometry.
Need to do a helium dilution test.
However, the point of RV is at the end of FVC expiration on the X axis.

Question 6

Forced vital capacity or Vital capacity

Answer 6

Volume you can breath in after blowing out until RV.

Question 7

Units of flow

Answer 7

Liters/sec or liters/min

Question 8

Inspiratory capacity

Answer 8

After a normal tidal volume exhalation, the volume you can breath in all the way.

Question 9

Inspiratory reserve volume

Answer 9

After a normal tidal volume inhalation, the volume you can breath all the way in

Question 10

Can you get forced expiratory volume in 1st second (FEV1) from a flow volume loop?

Answer 10

No, need to look at volume time plot

Question 11

Volume time plot axis

What are values you can get

Answer 11

Y- volume
X time

FEV1 and FVC

Question 12

If you stop short after FEV1, what can you not determine?

Answer 12

FVC

Question 13

Scooping of a flow volume loop indicates

Answer 13

Lower airway obstruction/narrowing (asthma, COPD, bronchiectasis)

Question 14

What do you see in a volume time plot of a patient with obstructive disease?

Answer 14

Reduced FEV1
However, if you give them enough time, can almost reach normal FVC.

FEV1/FVC ratio is reduced in obstruction

Give bronchodilator to restor FEV1

Question 15

What is air trapping and when do you see it?

Answer 15

Increased residual volume. Seen in obstructive diseases.

Give bronchodilator - less air trapping.

Question 16

A smaller flow volume loop is indicative of

Answer 16

Restriction

Question 17

What do you see in a volume time plot of a patient with restriction?

Answer 17

Reduced FEV1 and FVC

Therefore, the FEV1/FVC ratio stays the same or is slightly elevated

Question 18

What are causes of restriction?

Answer 18

Intrinsic: interstitial fibrosis, pulmonary edema

Extrinsic: kyphoscoliosis, obesity

Neuromuscular disease

Question 19

Pseudorestriction

Answer 19

The FVC is reduced because the residual volume is elevated