Fouty: Pulmonary Function Tests Flashcards
85% of patients who complain of dyspnea on exertion usually due to what 2 things
lung or heart disease
3 main diseases of the lungs
airways
interstitial
pulmonary vascular
the total work of breathing is a combination of what 2 things
restrictive work
elastic work
work that moves air in and out of lungs
resistance work
work that distends lungs and chest wall
elastic work
respiratory rate in a minute
frequency
tidal volume per breath
Vt
lung volume that is high has very little what
resistance
minimal work has a tidal volume of 400 and how many breaths per minute
12-18
purpose of PFTs (pulmonary function tests)
if pulmonary disease is present
type of disease
severity of disease
lung volumes
airflow
adequacy of pulmonary vasculature
respiratory muscle strength
variables measured by PFTs
normal breathing=
tidal volume
big breath in measurement
total lung capacity
blow all of the breath out
vital capacity
end up with some air in the lungs after expiration
residual volume
4 volumes that makes up total lung capacity
tidal volume
expiratory reserve volume
inspiratory reserve volume
residual volume
4 capacities
functional residual capacity
inspiratory capacity
vital capacity
total lung capacity
how to measure residual volume
FRC-ERV
how to measure TLC
VC + residual volume
breathing in and out normally, what point do you come back to
functional residual capacity (resting expiration)
what is activated if you want to go lower than functional residual capacity
muscles of expiration
what is activated if you want to go higher than functional residual capacity
muscles of inspiration
How Do You Determine Total Lung Capacity if You Can’t Measure Residual Volume?
functional residual capacity - expiratory reserve volume (then add that to vital capacity to get TLC)
a way to measure functional residual volume that has limitations of profusion of gas not being uniform
helium dilution
another way of measuring functional residual volume that uses boyle’s law
“body box”
lung volumes can be what 3 things
increased, decreased, normal
most important test to check lung volumes
total lung capacity (by body box)
2nd thing to look at to check lung volumes
functional residual volume
TLC or FRC > Upper limits of normal (ULN)
greater than 120% predicted per GOLD
lung volumes increased
TLC or FRC < Lower limits of normal (LLN)
Less than 80% predicted per GOLD
lung volumes decreased
a ______ TLC defines restrictive physiology
decreased
a way to measure airflow through the lungs
spirometry