PFT Flashcards
Two types of ventilatory region
Deadspace Ventilation and effective alveolar ventilation
It occurs in a ventilatory region where gas exchange perfusion is not available.
Deadspace ventialtion
where gas exchange perfusion is available
effective alveolar ventilation
The volume of the conducting airways from the mouth/nose down to and
including the level of the terminal bronchiole
Anatomic deadspace
The volume of malfunctioning alveoli that are lacking normal gas distribution
Alveolar deadspace
The total volume of deadspace in the pulmonary system; consists of the
the sum of the anatomic and physiologic deadspace combined; may also referred as “functional deadspace”
Physiologic deadspace
Alveolar units where the quantity of ventilation exceeds the quantity of perfusion available; result in a partial deadspace ventilation effect
ventilation in excess of perfusion
It measures the volume of a subject’s conducting airways. This provides a measure of the subject’s anatomic deadspace volume
Fowler method
What are the equipment required in Fowler test
rapid-response gas analyzer for nitrogen and spirometer system. Nitrogen washout for frc determination or single-breath nitrogen elimination test.
Test administration step 1
Inhale and breathe 100 % O2 through single-breath O2 inspiration
With inspiration, the subject’s alveoli contain a mixture of
N2 and the inspired
02
The presence of N2 results from the preexisting
residual volume gas
It differs, however, in that it allows room air instead of 100% 02-to be inhaled for the test. The tracing and calculations are based on FEC02 values measured during exhalation
Carbon dioxide meter in spirometer
Bohr Equation
deadspace over tidal volume is equal to the quantity of FACO2 - FECO2 over FACO2
The equipment needed to perform the bohr test includes
a spirometer for measuring exhaled volumes, a Douglas bag for collecting and exhaled gas sample, a CO2 analyzer, and an end-tidal PCO2 analyzing system or equipment for arterial blood sampling and analysis.
what is the duration of collection time of exhaled gas in Bohr tests
5-10 minutes
What is the normal values of Vd/Vt
.20 and .40
It is what states that alveolar deadspace begins to develop measurably and that Vd increases to become greater than the Vdan.
Pathologic states
What are the normal values for VAeff
31/min to 81/min
Relative increase in Vaeff can lead to
Hyperoxia and hypocapnia
Decreases in VAeff can cause
Hypoxemia and hypercapnia
If a rapid, shallow breathing pattern is adopted by the subject, there will be relatively
more deadspace ventilation and less effective alveolar ventilation
If a slower, deeper breathing pattern is adopted by the subject, there will be relatively
less deadspace ventilation and more effective alveolar ventilation
Increase anatomic deadspace is caused by
- Disorders that cause destruction or dilation of the airway walls (bronchiectasis) .
Breathing at a greater FRC level or with larger inspiratory volumes (air trapping/hyperinflation).
- Bronchodilator agents.
Decrease anatomic deadspace is caused by
Disorders that cause constriction (asthma) or obstruction (carcinoma) of the airways
Bronchoconstrictor agents.
Caused of increased alveolar deadspace (2)
Loss of perfusion and Reduce perfusion
Caused of loss of perfusion
pulmonary emboli
Caused of reduce perfusion
Decrease cardiac output/hypotension
Pulmonary hypertension
Caused of ventilation in excess of perfusion
Alveolar septal destruction
Positive pressure ventilation
What region of the lungs does larger alveoli present and vice versa
upper region, lower region
What is the reason on why lung bases received more ventilation
Because of their small size
The alveoli in peripheral, outer lung tissue receive
more ventilation than alveoli deeper within the lung.
The result of more ventilation in bases of the lungs
This is the result of intrathoracic pressure relationships
The result of peripheral alveoli receiving more ventilation than alveoli deep within the lungs
intrapulmonary tissue force relationship
In normal ventilation, the greater part of inspiratory / expiratory volume exchange occurs in
Lung bases
Region of the lungs that are responsible for holding a larger portion of the FRC volume.
Upper lung region
Increased compliance is caused by what disease
emphysema
Decreased compliance is caused by what disease
fluid or exudate collecting in the alveoli or interstitial space
atelectasis
tumors
fibrotic pulmonary disorder
Decreases airway resistance due to partial obstruction is caused by
asthma
bronchitis
peribronchiolar and intrabronchiolar tumors
Check valve expiratory obstruction is caused by what disease
emphysema
It involves having the subject inhale a breath of 100% oxygen
single-breath nitrogen elimination test (SBN2) or single-breath oxygen test
Phase I
The initial 0.0% N, concentration measured during the emptying of the Vdan.
Phase II
It is the the rapid increase in % N2 that indicates the transition from Vdan to alveolar gas.
Phase III
It is the relative % N2 plateau that results from the emptying of mixed gas from
the alveoli during expiration.
Phase IV
It occurs toward the end of the expiration in most subjects. It is a relatively rapid
increase in % N2 from the Phase III plateau that continues with exhalation to the RV level.
What are the equipments required for the SBN2 test
Gas analyzer for N2, spirometer system, a system for recording and producing tracing for the %N2 and Ve changes, and feedback system
Test admin summary for SBN2
Nose clip on and take 2 deep breaths to TLC level without a pause at peak and exhale to RV level while maintaining a flow rate of 0.3-0.5 or 0.4 (ideal) 1/sec.
What phase to determine Vdan by using fowler method
Phase II
What phase to determine uniformity ventillation in the lung
Phase III
_____Involves having the subject breathe the radioactive gas_____
Ventilation scans, Xenox 133
It is made of the lungs during the breathing of the gas
scintiscan
It is made to record the process and pattern of the distribution of the Xe’33
in the lungs.
Scintiphotograph
These scans allow a visual evaluation of the distribution of ventilation in the
lungs.
Ventilation scans
_____It involve the intravenous injection of a radioactively tagged substance_____
Perfusion scans, Iodine 131 and technetium 99
What is the commonly used carrier in perfusion scans
Human albumin
It is processed into_______ , or particles that are large enough to be caught and held in the _______.
microspheres, pulmonary capillary circulation
A region of the lungs that demonstrates a perfusion defect but has normal ventilation is strongly indicative of what disease.
pulmonary embolism
Subjects with______ often show matching ventilation and perfusion defects throughout the lung fields.
COPD
The flow-volume loop is plotted with flow indicated on the________ and volume on the_______
vertical axis, horizontal axis
T/F The PEFR is more easily read from a flow/volume loop than it is from a volume/time curve
T
Pulmonary function studies are interpreted by comparing a_______ with what are predicted to be________
subject’s test values, normal values for that subject
What parameter relates directly to changes in VC from volume spirometry. Evaluation of the flow-rate parameters below aids in disorder differentiation.
FVC
What parameter relates to flow rates and disorders in the large, upper airways. Very effort-dependent. Also used to monitor asthma and bronchodilator therapy.
PEFR
What parameter relate to flow rates and disorders in the large, upper airways. Still may be relatively effort-dependent.
FEV0.5, FEV1, FEF200-1200
What parameter relate to flow rates and disorders in smaller bronchi and larger bronchioles. Some degree of effort-dependence remains
FEF2, FEF25%-75%
What parameter relate to flow rates and disorders in smaller bronchioles. Little or no effort-dependence.
FEV3, FEF75%-85%
What parameter relates to changes in both flow rates and lung volumes. Generally, opposite results are demonstrated between restrictive and obstructive disorders.
FEVt%
what parameter relates most significantly to flow rates and disorders in the large upper airways.
FEFx%
Examples of disease under pulmonary restrictive disorders
Interstitial Fibrosis, Vascular congestion, Pneumoconioses, Sarcoidosis
Examples of Thoracic extrapulmonary restricted disorders
Kyphoscoliosis, Rheumatoid spondylitis
Examples of abdominal extrapulmonary restricted disorders
Ascites, peritonitis, severe obesity
Examples of neuromuscular defects extrapulmonary restricted disorders
Poliomyelitis. myasthenia gravis
Reductions in lung volumes (FVC and FEVJ occur in subjects with________
restrictive disorders
Most significant for making restrictive/obstructive differentiations are values for the______
FEVt%
With restrictive disorders, FEVt%, values will often be_____ than predicted.
larger
What parameter provides an additional resource for differentiating between restrictive and obstructive disorders.
RV, TLC, and RV/TLC% values
_________generally produce decreased values in the most of the parameters measured during an FVC maneuver. These decreases are due largely to the_________ that occur with obstructive disorders.
Obstructive disorders, airflow limitations
It provides a simple graphic representation of the parameters measured with forced expiratory and inspiratory VC maneuvers. More significantly, it also demonstrates a very characteristic shape in certain disorders.
Flow/volume loop
It quantifies the degree of concavity that the middle portion of the MEPV curve may have toward the volume axis.
Angle Beta
With a________ , the primary change is a decrease in_______ . The entire loop is displaced what direction to a lower level of lung volume
restrictive disorder, volume, downward
In_________ the latter portion of the expiratory loop begins to take on a_________ appearance, This concavity is most pronounced in subjects with what disease because of their greater sensitivity to dynamic airway compression. The entire loop is displaced to a higher lung volume.
small airway obstruction, concave, emphysema
What obstruction causes relatively equal decreases in both expiratory and inspiratory flow rates,
Fixed large airway obstruction
Intrathoracic variable large airway obstructions cause a flattening of the caused_________ by the limitations of the______ flow. This flattening occurs because obstructions of this type are exposed to the same dynamic forces as the lungs themselves.
expiratory portion of a flow/volume loop, expiratory
Extrathoracic variable large airway obstructions cause a flow limitation on________ , with a characteristic flattening of the________
inspiration, flow/volume loops inspiratory portion
Comparing the_______ values may be helpful in evaluating upper airway obstruction. These values will be reduced almost equally with a fixed obstruction
FEF50% and FIF50%
A________ will produce a greater decrease in the FEF50% value. A____________ will produce a greater decrease in the FIF50% value.
variable intrathoracic obstruction, variable extrathoracic obstruction
Among subjects of the same gender,________ is the single greatest factor that affects pulmonary function.
height
In______ , normal values are more directly related to height than to age.
children
This is true until a height of approximately________ is reached.
60 inches (152 cm)
The______ of the subject is sometimes taken into consideration along with the height. This is often done by using the value for the________ (BSA). The equation for calculating BSA is________ where the height (Ht) is in______ , the weight (Wt) is in______ , and the BSA is in______.
weight, subject’s body surface area, BSA= Ht^0.725 X Wt^0.425 X 0.007148, centimeters, kilograms, square meters
With adult subjects, especially after the age of______, advancing age tends to have a deteriorating effect on normal. pulmonary function values. As age increases, normal values decrease for
25
Lung volumes (exceptions arc RV and FRC, which increase with advancing age).
- Expiratory flow rates.
- Diffusing capacity
The gender of the subject affects predicted normal pulmonary function values. ________subjects tend to demonstrate greater___________ than_______ subjects of the same height and age.
Male, lung volumes, expiratory flow rates, and diffusing capacities, female
When male and female subjects with the same predicted normal FVC values are
compared, the________ subject will have greater predicted values for_______
female, expiratory flow rates.
What are the primary characteristics?
height, weight, age, gender
what are the secondary characteristics
Race/ethnic origin, altitude, air pollution, and other environmental factors
_______ subjects tend to demonstrate smaller predicted normal
values for a given height and age than subjects of______ origin.
Black and Oriental, European
It should be noted, however, that values for_________ are the same for both black and European-descent subjects who have the same________ .
predicted expiratory flow rates, predicted FVC values
Pollution caused by high levels of_______ (by-products of high-sulfur coal combustion) has been documented to cause deterioration in pulmonary function
“reducing”- type agents
Equations for predicting “normal” pulmonary function parameters are based on the testing of populations of______
“normal” individuals
Variables that must be controlled with pulmonary function testing to establish
normal values include the following:
The individual tested, the test procedures. the test equipment
The equations used to predict normal pulmonary function values are referred to as
regression equations
The equations used to predict normal pulmonary function values are referred to as_______
regression equations
Two types of regression equation
linear, non-linear
_______ are based on simple differences in gender, age, and height and offer relatively easy calculation of normal values.
Linear equations
________ allow calculation of predicted normals over a wider and possibly nonlinear range. It also allows the inclusion of other physical characteristics, such as ________
Nonlinear equations, weight
