Pulmonary Function Tests Flashcards
What is measured during a pulmonary function test?
volume or flow of air during inhale and exhale which includes measurements of forced vital capacity (FVC) peak expiratory flow (PEF), forced expiratory volme in first second (FEV1) and mid-expiratory flow (FEF 25-75%)
How do you conduct a Pulmonary Function Test?
- subject exhales into a spirometer as hard and as fast as possible for 6 seconds until no more air can be expelled
- needs 3 acceptable trials
What measurement would be the primary indicator of an obstructive impairment?
FEV1/FVC being below 70%
What percentage of FEV1/FVC is considered a mild obstruction?
70-99%
What percentage of FEV1/FVC is considered a moderate obstruction?
60-70%
What percentage of FEV1/FVC is considered a moderate to severe obstruction?
50-60%
What percentage of FEV1/FVC is considered a severe obstruction?
less than 50%
How are restrictive ventilatory impairments inferred from spirometry?
when FVC is reduced and FEV1/FVC is normal or above 80%
What characterizes a restrictive ventilatory impairment?
reduced lung volumes and relatively normal expiratory flow rates