PFTs Flashcards
What are the 5 components of the respiratory unit?
- Airways
- Alveoli
- Interstitium
- Capillary
- RBCs
When is it appropriate to order PFTs? (5)
- Evaluation of pts with suspected respiratory disease
- Eval of severity of respiratory disease
- Preop
- Eval of persons at risk for pulmonary disease
- Assessment of therapeutic response
True or false: you should never order PFTs in the acute setting
True
What are the three factors of respiration that are measured with PFTs?
Flow
Volume
Gas exchange
What is the normal Tidal Volume?
500 mL
What is the functional residual capacity?
Residual volume + expiratory reserve
What is the vital capacity?
TLC - residual volume (total volume that you can move)
What is inspiratory capacity?
Tidal volume + inspiratory reserve (total amount of air that you can move into your lungs, not including the residual volume)
What is the expiratory reserve volume?
Difference between the end of tidal volume expiration, and residual volume
Which lung volume cannot be measured with an inspirometer?
Residual volume
What is the first thing to check with a PFT result?
Name and date
What does spirometry measure? Is this a static or dynamic measure?
Flow
Dynamic
What do capacities measure?
Volume
What is used to determine gas exchange?
Carbon monoxide
What is body plethysmography?
Static measurement of lung volumes
What is DLCO? What is it used to assess?
Diffusion capacity of the lungs for CO. Used to evaluate gas exchange capacity of the lungs
Can spirometry be used to definitively diagnose restrictive lung disease?
No, but can aid in diagnosis
What are the three major factors that may affect the accuracy of spirometry?
- Inability to follow instructions
- Muscular weakness
- Poor oral seal
What is the reference population for PFTs based on? (4)
Age
Gender
Height
Race
What position must the patient be in to properly evaluate PFTs?
Seated
What happens to the lungs as we age?
Lose elasticity
What is FEV1?
Change in expiratory volume in the 1st second
Where is the FEV1 on a normal time-volume curve?
max of dV/dt
What is FEV25-75?
Forced expiratory volume in the 25-75% of the curve