Pulmonary Function Tests Flashcards
What is the difference between volumes and capacities?
Volumes can be measured, while capacities have to be summed from two or more volumes.
What are tidal volumes?
Normal inspiratory and expiratory breaths at rest
What is expiratory reserve volume?
The amount of air remaining in the lungs after a normal expiration that can be forcefully expired
What is inspiratory reserve volume?
The amount of air that can be inhaled after a normal inspiration has taken place
Functional residual capacity is ___________.
residual volume plus expiratory reserve volume
Inspiratory capacity is ______________.
inspiratory reserve volume plus tidal volume
Vital capacity is ________________.
inspiratory reserve volume plus tidal volume plus expiratory reserve volume
In terms of spirometry, the hallmark finding of obstructive diseases is ___________.
reduced FEV/FVC ratio
__________ diseases cannot be diagnosed with spirometry.
Restrictive
The latter 2/3 of expiration is ___________.
effort independent; it is determined by the elastic recoil of the lungs
The _______ side of the flow-volume loops is symmetric.
inspiratory
TGV is another term for __________.
functional residual capacity (FRC)
Name six causes of restrictive lung disease.
(1) pulmonary fibrosis
(2) pulmonary edema
(3) obesity
(4) neuromuscular disorders
(5) interstitial lung disease
(6) pleural disease
During resting breathing, _______ requires effort, but _______ happens spontaneously.
inspiration; expiration
Residual volume cannot be ________, it must be estimated.
measured
____________ represents the volume at which the elastic recoil of the lungs is balanced with the outward force of the chest wall.
Functional residual capacity
Inspiratory reserve volume is the volume that can be inspired after ___________.
a resting inspiration
The accepted “normal” range for % predicted is ______________.
80% - 120%
In a flow-volume loop, obstructive diseases will be ______________.
left-shifted and have a “coving” of the expiratory rate
The “flow-volume loop points to the obstruction” only works for __________.
variable obstructions; fixed obstructions (such as tracheal stenosis) are flattened on both sides
Helium volume tests are less accurate in those who have ____________.
obstructive diseases with air trapping
The only PFT whose predicted value can be >120% and still be considered normal is _________.
residual volume (which can go up to 140% and still be considered normal)
TLC and FRC will be low in _________.
restrictive disorders
What can decrease DLCO?
Emphysema, anemia, pulmonary edema, pulmonary vascular disease, and interstitial lung disease
DLCO corrected with helium volume tests can ___________.
determine if diffusion is appropriate given volume limitations
A bronchodilator test is considered positive when __________.
FEV and/or FVC increase by greater than 12%
FRC (aka TGV) is determined by _________.
lung compliance and chest-wall compliance
A flow-volume loop in a person with restrictive lung disease will also show _________, much like in obstructive disease.
reduced maximum flow (in this case due to increased resistance to air flow)
Extra-thoracic variable obstructions include ___________.
laryngeal edema and vocal-cord paralysis
Intra-thoracic variable obstructions include _______.
tracheal tumors
P(i[max]) measures ___________.
the maximal inspiratory force (against an occluded aperture)
What is the metacholine challenge?
Metacholine induces bronchoconstriction. Those with asthma require orders of magnitude less than those without asthma to induce an asthma attack.
