Pulmonary function tests

Question 1

What is the difference between obstructive and restrictive respiratory disorders?

Answer 1

Restrictive-These are extra-airway disorders that reduce the lungs capacity to fill

Obstructive-Airways diseases that cause obstructed airflow

Question 2

What is FVC and FEV(1)

Answer 2

FVC: Forced vital capacity, max volume that can be expelled from full lungs

FEV(1): Forced expired volume in 1 sec

Question 3

What do restrictive and obstructive diseases look like on an FVC chart?

Answer 3

Question 4

What is measured on a flow-volume loop?

Answer 4

Question 5

What do obstructive and restrictive diseases look like on a flow-volume loop?

Answer 5

Mild obstructive
-Reduced FVC
-Indented exhalation curve

Severe obstructive
-Reduced FVC
-Reduced PEFR
-Indented exhalation curve

Restrictive disease
-Reduced FVC
-Narrower curve

Question 6

What is the expected normal, restrictive and obstructive FEV1/FVC ratio?

Answer 6

Normal 4.3/5.1= 84%
Restrictive 3.3/3.3= 100%
Obstructive 1.0/1.9= 53%

Question 7

What does a flow-volume loop of a variable extrathoracic obstruction look like?

Answer 7

Question 8

What does a flow-volume loop of a variable intrathoracic obstruction look like?

Answer 8

Question 8

What does a flow-volume loop of a fixed airway obstruction look like?

Answer 8