PFT Study Guide
Contraindications include: - ANSWER-- pneumothorax (untreated)
- hemoptysis
- cardiovascular disease
- cataract removal surgery (ocular pressure)
Pulmonary function devices that collect and measure GAS volumes - ANSWER-- water sealed spirometer
- bellows spirometer
- dry-rolling-seal spirometer
Lung volumes - ANSWER-how much air your lungs can hold
Spirometry determines - ANSWER-how quickly you can move air in & out of your lungs
Diffusing capacity - ANSWER-how well your lungs add oxygen & remove carbon dioxide
Purpose of performing pulmonary function tests (PFTs) - ANSWER-- Functional *status* of the *lungs*
- *How MUCH & how FAST GAS* can be moved into and out of the lungs
- *Diffusion characteristics* of the alveolar-capillary membrane
*the tests can dx. lung diseases & measure the severity of the disease*
Parameters to establish normal values for PFTs - ANSWER--*G*ender -*H*eight -*R*ace
- Age
What is the most important factor influencing lung size and predicted values? - ANSWER-*Height*
the taller the person, the larger are predicted lung volumes, flow rates, and diffusing capacity.
Lung volumes and flow rates are affected typically when the BMI is greater than: - ANSWER-*BMI>30*
as a person gains weight, lung volumes and flow rates do not changes until the person becomes obese (BMI>30)
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The instrument used primarily in PFT - ANSWER-Spirometer (for measuring routine *flows* & *volumes*)
Standard equipment in a pulmonary function laboratory - ANSWER-- Spirometer
- Gas analyzer
- Body plethysmograph
What is the volume of air inhaled and exhaled during quiet breathing? - ANSWER-tidal volume (Vt)
Normal minute ventilation of an average person at rest - ANSWER-4 to 12 L/min (depending of the size of the pt.)
Why is proper coaching of the pt. during FVC maneuver extremely important? - ANSWER-*ERRONEOUS FVC* test results (most common)
Restrictive lung disorders reduce FVC by - ANSWER-shrinking the lung (decrease in lung size)
Obstructive lung disorders reduce FVC by - ANSWER-increase in RV (caused by air trapping)
If measured FVC is significantly smaller than SVC, what is occurring? - ANSWER-air trapping
What level of VC is associated with *increased risk of postoperative respiratory complications*? - ANSWER-<20 ml/kg (reduced VC)
What level of VC is associated with *increased risk of respiratory failure*? - ANSWER- <15 ml/kg
indicates that the ventilatory reserve is decreased enough to cause resp. failure
Total lung capacity (TLC) is a function of the persons - ANSWER-- *A*ge
- *R*ace
- *S*ize
_ *G*ender
*reported as the Measured volume and as % Predicted*
The body plethysmograph uses which gas law? - ANSWER-Boyles law
The closed system helium dilution method is used to measure - ANSWER-FRC
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