Pulmonary Function Testing Flashcards
Volume of air inspired and expired with each normal breath
Tidal Volume
Amount of air that can be forcefully expelled beginning with lungs completely full and blowing until lungs are empty
Forced Vital Capacity (FVC)
Amount of air expelled in the first second of the FVC maneuver
Forced Expiratory Volume in 1st second (FEV1)
What is the FVC maneuver?
Amount of air expelled beginning with the lungs completely full and blowing until the lungs are as empty as possible
Volume of air remaining in lungs after expiration
Residual Volume
Maximum volume to which lungs can be expanded with inspiration
Total Lung Capacity (TLC)
What are some indications to perform Pulmonary Function Tests (PFTs)?
- Dyspnea, cough, asthma, COPD
- Suspected bronchiectasis, ILD, chest wall diseases
What are 5 components of PFTs?
- Spirometry
- Lung volumes/capacities
- DLCO
- Bronchodilator therapy
- Bronchoprovocation
Spirometry flow volume curve shows?
Expiration only
Spirometry flow volume loop shows?
Expiratory and Inspiratory flow
What does Spirometry measure?
FVC
FEV1
FEV1/FVC ratio
What does Body Plethysmography measure?
Residual volume
Total Lung Capacity
DLCO
Diffusing capacity of lung for Carbon Monoxide
What does DLCO measure?
Gas exchange through the alveolar wall
How is DLCO performed?
- Diffusing capacity of the lung for Carbon Monoxide
= Patient inhales CO, holds breath, then exhales and the CO is measured to calculate the DLCO
When is Bronchodilator Therapy used?
With Obstructive Lung Disease to determine if it is reversible
What is given for Bronchodilator Therapy?
Albuterol (beta 2 agonist)
When is Bronchodilator Therapy (+) and what does that conclude?
Greater than 12% increase in FEV1 or FVC AND volume increase greater than 200 ml
= Asthma
When is Bronchodilator Therapy (+) and what does it conclude?
Greater than 12% increase in FEV1 or FVC AND volume increase greater than 200 ml
= Asthma
If Bronchodilator Therapy is (-), what does that conclude?
COPD or other obstructive lung disease
When is Bronchoprovocation used?
When PFTs are normal but Asthma is still suspected
Most common type of Bronchoprovocation used?
Methacholine challenge
– Ach analog used to (+) mAchR = Bronchoconstriction
DDX for Obstructive Lung Disease
COPD: chronic bronchitis, Emphysema
Asthma
Bronchiectasis, Bronchiolitis
How does the Obstructive lung disease flow volume curve look?
Concave
How does the Restrictive lung disease flow volume curve look?
Peaked, steeple, witch’s hat
Spirometry results for Obstructive Lung Disease?
FEV1 < 80% predicted
FEV1/FVC ratio < 0.7!!!!!
Lung volume results for Obstructive Lung Disease?
INCREASED residual volume and TLC
DLCO results for Emphysema with obstructive lung dz?
LOW
– Others = normal
Spirometry results for Restrictive Lung Disease?
FVC < 80% predicted
FEV1/FVC ratio normal > 0.7
Lung volume results for Restrictive lung dz
DECREASED residual volume and TLC
DLCO results for Interstitial Lung Disease (restrictive)
LOW
– Others = normal
What PFTs results will be present with MIXED disease?
- FEV1/FVC = LOW
- TLC = LOW and is < 5% of predicted
What PFTs results will be present with MIXED disease?
- FEV1/FVC = LOW
- TLC = LOW and is < 5% of predicted
FEV1/FVC ratio must be less than ____ to be considered an Obstructive Lung Disease
LESS than 0.7
