Lecture 9: Pulmonary function testing Flashcards
What four aspects of pulmonary function can be tested?
- Ventilation (inc lung mechanics)
- Gas-exchange
- Perfusion (quality and quantity)
- Respiratory control
What does respiratory function testing performed to assess;
- Impact of a pathological or aging process
- To track the progress of a disease process and/or treatment regime
- Assess degree of interventional risk or risk associated with specific activity
What are some generic lung function tests commonly used?
- Spirometry
- Static lung volumes
- D(lco) (diffusion capacity)
- Bronchodilator response
- Bronchoprovocation tests
- Cardiopulmonary exercise testing
What are some indications to use spirometry / FVC?
- Establish obstructive disease
- Assess intervention impact
- Pre-op evaluation
- Assess work related exposures
What happens with pulmonary function with age?
Declines after 25
What impacts PV loop?
- Age, height, gender, changes the normal
How are static lung volumes measured?
Measure all static volumes and capacities of the lung
- Plethsmyography
- He dilution (C1V1=C2V2)
- N2 wash-out
What indications for static lung volume test?
Measurements of static lung volumes are used to establish or confirm diagnosis of Restrictive lung disease
How does static plethysmography;
Boyles law: P1V1 = P2V2
What is D(lco) used for?
Alveolar capillary diffusion assessment
Evaluates the transfer of gas from the air spaces into the pulmonary capillaries
What are the indications for D(lco)?
- Evaluations and follow up parenchymal lung disease
- Differentiating among chronic bronchitis, emphysema, and asthma
- Evaluates pulm. involvement in systemic diseas
What is the D9=(lco) equation?
Rate of diffusion = area (conc. grad / thickness)
Uses Carbon monoxide
What is the bronchodilator response?
The degree to which bronchodilators can ameliorate the effect of airway obstruction can be assessed with PFTs
- FEV1 increase 12-15% ~200mL indicates reversibility.
What are the indications for a bronchodilator response;
- Preop evaluation of obstruction reversibility
- Reversal of bronchospasm induced by bronchial challenge test
- Evaluate treatment regime
- Reverse airway obstruction
What is the use of a bronchoprovocation test?
- Evaluate airway hypersensitivity
BUT no tests are 100% sensitive and specific
