PFTs Flashcards
define elasticity
Tendency of a hollow organ to return to its original size when distended
Define compliance
The measure of the expandability of a lung
What is the relationship between compliance and elasticity?
inverse
What process of breathing is affected in restrictive lung disease?
Inspiration primarily affected
Define restrictive lung disease
- Function of compliance and elasticity
- Lung compliance low
A. Increased stiffness of lung limits chest expansion (Volume)
Define obstructive lung disease?
- Disturbance in ventilation due to increased airway resistance
A. Difficulty exhaling quickly due to increase in airway resistance (Flow)
What process of breathing is affected in obstructive lung disease?
expiration is primarily affected
What is the typical test done for PFTs?
Plethysmograph
What does spirometry measure?
Measurement of Air Flow Rates
Calculation of Lung Volumes & Capacities
When is spirometry performed?
Usually done pre-surgery or to see how well a bronchodilator works
What do Gas Diffusion & Inhalation Tests measure?
Measures amount of gas exchange at alveoli/min.
What does Exercise Pulmonary Stress Testing measure?
estimation of pulmonary reserve
What are the indications for PFTs?
- Detect the presence of lung disease
- Quantify the extent of the lung disease
- Measure the effects of occupation and the environment
- Determine the benefits of the therapy (i.e. bronchodilators)
- Assess the risk for surgery
- Evaluate disability of impairment
- Disease research
What are spirometry results dependent on?
age, height, weight
How long must a FVC maneuver last?
6 seconds
What are examples of obstructive pulmonary diseases?
COPD
Asthma
Bronchiectasis
Bronchitis
What are the FEV1, FEV, and FEV1/FVC results for obstructive pulmonary disease?
Dec FEV1
Dec FEV
Dec FEV1/FVC
< 70% predicted
What are the TLC and RV results in obstructive pulmonary disease?
Inc TLC
> 120% predicted
Inc RV
> 120% predicted
What test is used to assess severity in COPD?
FEV1
What is the FEV1/FVC ratio used for?
used to determine pattern (obstructive, restrictive, mixed , normal)
Define restrictive lung disease
A category of extrapulmonary, pleural, or parenchymal respiratory diseases that restrict lung expansion
What happens to lung volume, work of breathing and perfusion in restrictive lung diseases?
↓ lung volume, ↑ work of breathing & ↓ perfusion
What are the PFT results in resreictive lung disease?
↓ FVC
what are some examples of restrictive lung disease?
Pulmonary Fibrosis Sarcoidosis ARDS Kyphosis Obesity Myasthenia Gravis
what is the FEV1/FVC in restrictived lung disease?
FEV1/FVC is normal or increased
What are the FEV1, FVC, TLC, and RV values in restrictive lung disease?
- Dec FEV1
- Dec FVC
A. Always check this for restrictive disease - Dec TLC
A. < 80% predicted - Dec RV
A. < 80% predicted
What is respiratory failure?
Inadequate gas exchange by the respiratory system
Arterial oxygen and/or carbon dioxide levels can’t be maintained w/in their normal ranges
