pulmonary Review: PFT's and Diagnostic procedures Flashcards
consolidation
- a radiologic sign seen when a region of the lung is filled with something other than air
Infiltrate
- infiltrate implies that the substance (other than air) has infiltrated the lung tissue which is usually less density than consolidation
- cough
- SOB
- tachypnea
- possible fever
Pleural effusion
What it and most common symptoms
collection of fluid, air or blood in the pleural space - crushes the lung
- cough
- pain
- SOB
- tachypnea
Pulmonary tests
- ventilation/perfusion (V/Q) scans
- bronchoscopy
- chest imaging
- pulmonary function test (PFT)
V/Q scan
- radioactive isotopes are breathed in and radioactive iodine in the blood is injected
- can have one or both (look at V or Q)
- normal V/Q = 0.8
- there is typically more gas exchange seen in the lower parts of the lung due to gravity
Pulmonary function tests
- spirometry
- plethymysography
- expired gas analysis
Bronchoscopy
- can visualize an airway with a scope that goes down
- can clip off tissue for a biopsy
- can also use a balloon to open an airway if needed
What does it look at/used for
CT/MRI
- chest imaging
- changes in density
- abnormalities
- can be used to find mucus plugs
Aspiration pneumonia
- can be caused by a weak gag reflex
- swallowing dysfunction
- drug or alcohol abuse
Hypoxic vasoconstriction
- not enough ventilation = lungs will vasoconstriction to shift more blood to areas of better ventilation
- overtime this can cause pulmonary HTN
- pulmonary HTN can lead to right sided heart failure
Spirometry - interpretation of flow volumes and rates
- usually compared to predicted based on age, gender, height, weight and race
- determine if results are normal
- determine if results are indicative of obstructive or restrictive diseases and compare results over time
- consider H&P, serial PFTs, and patient signs and symptoms to determine disease progression
define the volumes of the lung
- Tidal volume: amount of air during quiet breathing
- IRV: amount that can be breathed in over TV
- ERV: amount that can be exhaled over TV
- RV: the amount always remaining in the lungs
Describe the capacities of the lung
- TLC: the total amount of air that can fit in the lungs
- VC: the total amount of air that you can control (IRV+TV+ERV)
- FRC: the amount that remains in the lungs after normal exhale
- IC: the amount that can be inspired after normal exhale (IRV+TV)
What does spirometry measure
- how fast and how much air you breath out
- can be used to look at volumes and rates
Tests to measure residual volume and functional residual capacity
- harder to measure RV
- can be measured by
- body plethysmography
- expired gas analysis: nitrogen washout test, helium dilatation test, diffusing capacity of carbon monoxide (DLCO)
Body plethysmography
- air tight box with pressures at a known value
- room measures changes in pressure and volume as patient exhales
- allows calculation of residual volume and functional capacity
Nitrogen washout
- open circuit method
- patient breaths 100% oxygen while the nitrogen washed out of the lungs is measures
- assumes 79% of lung volume is nitrogen
Helium dilution/diffusing capacity of carbon monoxide
- closed system
- known volume and concentration of gas inhaled and will be diluted proportional to the size of the lung volume e
- measured what the concentration of gas is at expiration
Obstructive lung diseases (COPD
- characterized by reduction in airflow with retained volume
- difficulty with exhalation related to air trapping
- examples: emphysema, chronic bronchitis, asthma, bronchiectasis
Restrictive pulmonary disorders
- characterized by reduction in volume
- difficulty with inhalation primarily due to stiffness of chest wall or lung tissue
- examples: interstitial lung disease, scoliosis, neuromuscular disease, obesity, injury
Total lung capacity in restrictive disorders and obstructive disorders
- restrictive = unable to expand but the proportion of each volume stays the same (each just gets smaller) = smaller TLC
- obstructive: have trouble with exhalation and therefore RV gets really large = increased TLC
Forced expiratory volume as a diagnostic criteria using FEV/FVC
- normally all the air is expired in 3 seconds (mostly in the first second)
- with a bronchospasm or COPD there is a decreased flow rate and it takes longer to FEV to get to 0
How does each of these compare to normal with a restrictive disoreder
1. VC
2. FVC
3. FEV
4. FEV/FVC
5. FEF
6. TLC
7. RV
8. FRC
- VC = decreased
- FVC = decreased
- FEV = decreased
- FEV/FVC = normal (ratio)
- FEF = decreased
- TLC = decreased
- RV = decreased
- FRC = decreased
How does each of these compare to normal with an COPD condition
1. VC
2. FVC
3. FEV
4. FEV/FVC
5. FEF
6. TLC
7. RV
8. FRC
- VC = normal/decreased
- FVC = normal/decreased
- FEV = decreased
- FEV/FVC = decreased
- FEF = decreased
- TLC = normal/increased
- RV = normal/increased
- FRC = normal/increased
