EXAM #1: PULMONARY FUNCTION TESTING Flashcards
What are the indications to perform Pulmonary Function Testing?
1) Evaluation of suspected respiratory disease
2) Evaluation of the severity of respiratory disease
3) Pre-op eval.
4) Evaluating persons at risk for pulmonary disease
5) Assessment of response to therapy
This is NOT done in the acute setting
What are the elements of pulmonary function testing?
1) Flow
2) Volume
3) Gas exchange
What is the tidal volume?
Air in/out with normal breath (500 mL)
What is the inspiratory capacity?
TV + IRV
What is the functional residual capacity?
ERV + RV
What is the vital capacity?
TV + ERV + IRV
What is the total lung capacity?
TV + ERV + IRV + RV
What does spirometry measure?
Air flow
What does body plethysmography measure?
Static lung volumes
What is the Diffusing capacity of the Lungs for Carbon monoxide (DLCO) measure?
Gas exchange
What is FEV1?
Forced Expiratory Volume in the 1st second
What is FVC?
Foriced Vital Capacity
What is PEF?
Peak Expiratory Flow
What are three factors that can negatively effect the accuracy of Spirometry?
1) Inability to follow instructions
2) Muscular weakness
3) Poor oral seal
When is most of the air exhaled in spirometry?
FEV1
What happens to the FEV1/FVC ratio in obstructive disease?
Decreased
What is the marker for severe obstructive disease in terms of FEV1/FVC ratio?
Less than 50%
What are the obstructive airway pathologies?
1) Asthma
2) COPD
3) Bronchiectasis
4) CF
5) Upper airway obstruction
6) Extrinsic airway narrowing
7) FB
Draw the flow-volume loop for obstructive lung disease.
N/A
Draw the volume-time curve for obstructive lung disease.
N/A
How does the peak flow differ between obstructive and restrictive lung disease. Draw the difference.
Obstructive= reduced and “scooped out” or steeple
Restrictive= normal peak but reduced volume
How does airway obstruction alter the flow-volume loop?
Blunted inspiratory phase
*“Variable extra-thoracic obstruction” is how the graph is read
How will variable intrathoracic obstruction appear on flow-volume loop?
Blunted expiratory phase
Draw the flow-volume loop for fixed airway obstruction.
N/A
What is the indication for a bronchoprovocation test?
To evaluate airway hyperresponsiveness
What is the most commonly used drug for a bronchoprovocation test?
Methacholine
What is a positive bronchoprovocation test?
FEV1 decreased by 20%
What are the techniques to measure lung capacity?
1) Body plethysomography*
2) Nitrogen wash out
3) Helium technique
What is the major difference between what can be measure with body plethysmography and spirometry?
Able to measure residual lung capacity and diagnose restrictive lung disease
What is the normal TLC?
80-120% of the normal
What defines restrictive lung disease?
Less than 80% of reference TLC
What defines hyperinflation?
More than 120% of reference TLC
What are the restrictive lung disease pathologies?
1) NM
2) Skeletal
3) Diaphragmatic paralysis
4) Pleural disease
5) Parenquimal
What is the utility of the DCLO in diagnosing restrictive lung disease?
Normal= extrapulmonary
Low= intrapulmonary
What is the utility of MIP and MEP (maximal inspiratory and expiratory pressures) in PFT?
Helps diagnose neuromusclar disorders
