Question | Answer |
What are the 3 divisions of the respiratory system | airways
parenchyma
chest |
What is diffusion in the lungs | air exchange across alveolar capillary membranes |
What are PFTs used for | evaluate how lungs work
-how much air lung can hold
-how quickly air moves in and out
-how well lungs add o2 and remove co2 |
Why do we do PFTs | diagnose dyspnea/cough or shortness of breath to see if it is obstructive or restrictive problem |
When would you order a PFT | evaluate s/sx of lung disease
assess progression of lung disease
monitor tx
evaluate preoperative patient
screen people at risk for pulm disease |
What does spirometry measure | measures air movement can determine how much and how fast air can be inhaled and exhaled |
What does diffusing capacity measure | ability of lung to transfer/exchange gases |
what is residual lung volume | amount of air left in lung after maximal expiration |
What is SVC | slow vital capacity- volume of air which can be inhaled or exhaled in a slow steady maneuver |
what is FVC | forced vital capacity- amount of air that can be exhaled with force after deep inhalation |
what is VC | vital capacity- the maximum volume of air exhaled during FVC or SVC |
What is TLC | Total lung capacity- VC + residual volume is the total volume of air at full inhalation |
What is ERV | expiratory reserve volume- maximum volume of additional air that can be exhaled after a normal exhalation |
What is IC | inspiratory capacity- max volume of air that can be inspired from tidal volume and expiratory level |
What is TV | Tidal Volume- air inhaled and exhaled at rest |
What is FET | forced expiratory time- the time it takes patient to complete FVC maneuver (exhale all air after maximal inspiration) |
What is FEV1 | forced expiratory volume in 1 second- volume of air forced out in 1 second |
What is FEV1/FVC | ratio of FEV1 to FVC |
on a peak flow volume loop what if PEFR and PIFR | Peak expiratory flow rate, and Peak inspiratory flow rate |
What are FEF25, 50 and 75 on flow volume loop | flow rate at which 25, 50 and 75% of volume has been exhaled |
What is DLCO | diffusing capacity of lung- measure ability of lungs to transfer carbon mononxide gives a measurment of how well the lungs are working with gas exchange |
What are the following values for FVC test
normal
mild reduction
moderate reduction
sever reduction | normal FVC= 80-120%
mild= 70-79
moderate- 50-69
severe- below 50 |
What would be a normal FEV1 | 75-80% |
What would be a normal fev1/FVC ratio | 70% |
What would be a normal fef25-75 | greater than 50% would be normal |
What are the standards for pulm function tests based on | age, height, and sex |
Can you measure TLC with spirometry | NO because you can't measure RV |
What would be a normal TLC | 80% |
How can you measure RV | nitrogen washout, helium dilution, body plethysmography |
IF you think patient may suffer from asthma but they don't have s/sx currently what can you administer to get a spirometry that would show if they have it or not | methacholine, bronchial provocation test |
compared to normal flow volume loop what would an obstructive disease look like | width would be same but expiratory curve slope would be decreased and flattened |
Compared to normal flow volume loop what would a restrictive disease look like | narrower loop less volume exchanged but slopes would be steeper |
what is a characteristic of a restrictive airway disease | decreases lung volume, decreased TLC and FVC but normal or increased FEV1/FVC ratio |
What is characteristic of an obstructive airway disease | outlow limitation TLC and Lung Volume normal but low FEV1 FEV1/FVC and FEF25-75 |
What type of airway disease is asthma | obstructive |
what type of airway disease is COPD | obstructive |
How do you generally differentiate between COPD and Asthma | get a DLCO COPD will have a diminished DLCO asthma will be normal |
What type of airway disease is interstitial lung disease | restrictive |
What type of airway disease is chest bellows diseases | restrictive |
how do you distinguish between interstitial airway disease and bellows disesases | DLCO test- Interstial will have impaired gas exchange, Bellows lungs gas exchange is normal but can't get air in |