Respiratory - Lung Function Tests Flashcards
What lung function test is used to diagnose obstructive and restrictive diseases?
Spirometry
What is reversibility testing?
Giving a bronchodilator e.g. salbutamol before repeating to see if results are impacted
What is FEV1?
Forced Expiratory Volume in 1 second
How much air can be forcefully exhaled in 1 second
Measures airflow out of the lungs, reduced with obstruction
What is FVC?
Forced Vital Capacity
How much air can be exhaled after full inhalation
Volume of air person can take into lungs, reduced with restricted lung capacity
What is obstructive lung disease?
FEV1 less than 70% of the FVC
Obstruction is slowing passage of air out of the lungs, may have good lung volume but air moves slowly due to obstruction
What picture on spirometry do you get with asthma and COPD?
Asthma
Obstructive due to bronchoconstriction
COPD
Obstructive due to chronic airway and lung damage
Both reversible, more in asthma
What is restrictive lung disease?
FEV1 and FVC equally reduced
FEV1:FVC greater than 70%
Lungs ability to expand fill with air reduced
Causes inadequate ventilation of alveoli and insufficient blood oxygenation
What causes the FEV1:FVC ratio is restrictive lung disease?
FVC restricted due to restriction of lung expansion and capacity
What are some examples of restrictive lung disease?
Interstitial lung disease (idiopathic pulmonary fibrosis)
Sarcoidosis
Obesity
Motor neurone disease
Scoliosis
What is peak flow?
Measures the peak of expiratory flow of air
What is peak flow used for?
See how well lung disease is controlled or when there is an exacerbation of obstructive lung disease especially asthma
What is the technique for peak flow?
Stand tall
Deep breath in
Good seal around the device
Blow as fast and hard as possible into device
3 attempts record best result
How is predicted peak flow calculated?
Sex
Height
Age
