Lung Function Tests & Common Lung Diseases Flashcards
What is meant by a obstructive lung disease?
Obstruction of air flow, especially on expiration
What is meant by a restrictive lung disease?
Restriction of lung expansion
Name two obstructive lung diseases.
Asthma and COPD
Name two diseases which fall under the category of COPD
Chronic bronchitis
Emphysema
What is chronic bronchitis?
Inflammation of the bronchi
What is emphysema?
Destruction of the alveoli and loss of elasticity
List some restrictive lung diseases.
Fibrosis, Infant Respiratory Distress Syndrome, Oedema and Pneumothorax
What is fibrosis?
A condition in which formation of excess fibrous connective tissue creates a “stiff” lung
Name the two types of fibrosis.
Idiopathic and Abestosis
What is the cause of abestosis?
Occupational related like breathing in coal dust.
Do restrictive lung diseases impact on inspiration or expiration?
Inspiration
Do obstructive lung diseases impact on inspiration or expiration?
Expiration
Why would infants have Infant Respiratory Distress Syndrome?
If they were born before 36 weeks as insufficient surfactant production, increasing surface tension.
What is pulmonary oedema?
Fluid building up around the alveoli.
What technique measures lung function?
Spirometry
Which two ways can measurements obtained via spirometry be classified?
Static or dynamic.
What is meant by a static spirometry measurement?
Only consideration made is the volume exhaled
What is meant by a dynamic spirometry measurement?
Time taken to exhale a certain volume is what is being measured
List the different things spirometry can measure.
Tidal volume
Inspiratory reserve volume
Expiratory reserve volume
Inspiratory capacity
Vital capacity
What does FEV1 refer to?
Forced expiratory volume in 1 second
What is the usual FEV1 value for young, fit, healthy males?
4L
What does FVC refer to?
Forced vital capacity- total amount of air you can expire over anytime.
What is the usual FVC value for young, fit, healthy males?
5L
What is the FEV1 to FVC ratio in a healthy male?
80%
(4/5=80%)
The values for FEV1 or FVC can vary depending on what?
Age, gender and height
What is the normal FEV1 for those with obstructive lung dieases?
1.3
What is the normal FVC or those with obstructive lung diseases?
3.1
What is the normal ratio for those with obstructive lung diseases?
42%
What is the normal FEV1 for those with restrictive lung diseases?
2.8
What is the normal FVC for those with restrictive lung diseases?
3.1
What is the normal ratio for those with restrictive lung diseases?
90%
Why is the ratio in those with restrictive lung diseases normal?
The impact on lung capacity can be huge, meaning there is simply less air to flow (which reduces FEV1) but the air that does flow is not obstructed. As such both FEV1 and FVC reduce in proportion and the ratio remains normal or may even increase.
Briefly explain FEV1, FVC and ratio of obstructive diseases.
FEV1 reduced a lot, FVC reduced a little so ratio is reduced a lot.
Briefly explain FEV1, FVC and ratio of restrictive diseases.
FEV1 reduced a lot, FVC reduced a lot so ratio unchanged or increases.
Why is absolute airflow of restricted diseases reduced?
Lung volume decreased in the first place.
