Lung Function Tests Flashcards
What is spirometry?
What is reversibility testing in spirometry?
Used to measure volumes of air and flow rates to provide objective measure of lung function
Reversibility testing= bronchodilator given prior to repeating spirometry to see the impact on results
-used to differentiate between astham and COPD when spirometry shows restrictve picture i.e. obstructive picture is reversible with bronchodilator in asthma
What is FEV1?
When will it be reduced?
Forced expiratory volume in 1 second
-measures ability of air to freely flow OUT of lungs
Reduced in obstructive disease i.e. asthma or COPD
What is FVC?
When will it be reduced?
Total amount of air a person can exhale after full inhalation I.e. total volume of air person can take into lungs
Reduced in restrictive disease
How is obstructive disease diagnosed and why?
Which conditions are classified as obstructive disease and how would you differentiate between them?
FEV1:FVC ration <0.75
- means that FEV1 reduced more than FVC suggesting obstructive picture
- person may have good lung volume but is unable to move air quickly due to obstruction
Asthma and COPD
-reversibility test using bronchodilator= obstructive picture reversed in asthma when broncodilator given
How is restrictive disease diagnosed and why?
Which conditions are classified as restrictive disease?
FEV1 and FVC equally reduced
FEV1:FVC >0.75 due to restriction preventing the lungs from taking in a normal volume of air
ILD
MND (motor neurone disease)
Scoliosis or chest deformities
Obesity
What does a peak flow meter measure?
What conditions is it useful in and why?
What 3 patient factors need to be taken into account when looking at peak flow graph?
Measures the peak expiratory flow rate i.e. the fastest point of a persons expiration
-acts to measure how much obstruction to airflow there is in someone lungs
Asthma
- measure how well asthma is controlled
- measure how severe asthma exacerbation is
Age/sex/height
