Pulmonary Function Test Flashcards
What are some reasons to do respiratory function tests?
Eval Pt with suspected disease Eval of severity Pre-op evaluation Eval those at risk Asses response to therapy
What are the variables assessed by PFTs?
Flow (air movement)
Volume (size)
Gas Exchange: oxygen and CO2
What is the average tidal volume?
500ml
What are the components of Functional residual capacity?
Expiratory reserve volume
Residual volume
What are the components of Inspiratory capacity?
Inspiratory reserve volume
Total Volume
What are the components of Vital capacity?
Inspiratory reserve volume
Total Volume
Expiratory reserve volume
What is the difference between Spirometry and Body plethysmography?
Spirometry: Dynamic measurement (air flow)
Plethys: Static Measurement (lung volumes)
How is gas exchange ability assessed?
Diffusing capacity of the Lungs for Carbon mOnoxide(DCLO)
What is the FEV 1?
Forced Expiratory Volum in 1st second
What is the criteria for a SEVERE obstruction to airflow?
FEV1 less than 50%
What changes about FEV1 and Spirometry in Restrictive lung disease?
FEV 1 and FVC are lower than normal but FVC(plateau) is reached after the same amount of time. same volume
What changes about FEV1 and Spirometry in Obstructive lung disease?
FEV 1 is much lower and FVC(plateau) is reached much more gradually.
What is the appearance of the flow volume curve in obstructive lung disease?
Reduced peak flow, Steeple pattern, concave/scooped out
What is the appearance of the flow volume curve in restrictive lung disease?
Normal Shape, normal peak flow, reduced volume
Is an obstruction worse during inspiration or expiration?
Inspiration! (croup, vocal cord dysfunction)
