Thank you for participating in our Spirometry Module. The answer key follows:
#1 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort . The FEV1 is reduced (73% predicted), the FVC is
normal (93% predicted) and the FEV1/FVC ratio is low demonstrating mild
obstruction (answer 3). This is confirmed by the coved expiratory limb
of the flow-volume loop.
#2 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort. The FEV1, FVC, and FEV1/FVC are normal. The
flow-volume loop is normal. This is a normal spirogram (answer 1).
#3 - The volume-time plot reveals a poor start to the test, a irregular
upstroke on expiration, and a poorly sustained plateau that all indicate
variable effort . This test is uninterpretable as it fails
acceptability criteria (answer 9).
#4 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort. The FEV1 is severely reduced (28% predicted) and the
FEV1/FVC ratio is low. This is consistent with severe obstruction as
confirmed by the coved expiratory limb of the flow-volume loop.
However, the severe reduction in FVC (40% predicted) implies a possible
concurrent restrictive defect. (answer 5).
#5 - The volume-time plot reveals a somewhat slow start to the test, but a
brisk upstroke to expiration and a sustained plateau both indicate
an adequate effort . The FEV1, FVC, and FEV1/FVC ratio are all normal.
However, the FEF25-75 are markedly reduced (40% predicted). This
suggests the possibility of early obstruction of small airways, visible
as the terminal coving of the flow-volume loop expiratory limb (answer
2).
#6 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a long, sustained plateau that all indicate
an adequate effort . The FEV1 is severely reduced (36% predicted), the
FVC is normal, and the FEV1/FVC is low. This indicates severe airways
obstruction (answer 4) and is confirmed on the flow-volume loop with a
markedly coved expiratory limb and a normal inspiratory limb.
#7 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort . The FEV1 is mildly reduced, the FVC is moderately
reduced, and the FEV1/FVC is high. The flow-volume loop is narrow but
of normal shape. This suggests a restrictive defect (answer 6).
#8 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort . The FEV1 and FVC are normal, but the FEV1/FVC and
FEF25-75 are reduced. This suggest possible early obstruction.
However, the flow-volume loop reveals a marked flattening of both the
inspiratory and expiratory limbs. This suggests a possible fixed upper
airway obstruction (answer 8). In this case, subglottic stenosis years
after intubation for general anesthesia.
#9 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort . The FEV1, FVC, and FEV1/FVC are normal. However, the
flow-volume loop demonstrates a flattened inspiratory limb despite a
normal expiratory limb. This suggests the possibility of a variable
extrathoracic airway obstruction (answer 7). In this case, laryngeal
dyskinesia - vocal cord asthma.
#10 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a sustained plateau that all indicate an
adequate effort . The FEV1 is mild to moderately reduced (68%
predicted), the FVC is normal, and the FEV1/FVC is reduced. The
flow-volume loop has a coved expiratory limb with a normal inspiratory
limb. This spirogram demonstrates mild to moderate obstruction (answer
3).
#11 - The volume-time plot reveals a delayed start to the test, an
irregular upstroke on expiration, and a poorly sustained plateau that
all indicate a poor effort . This spirogram is uninterpretable as it
fails to meet acceptability criteria (answer 9).
#12 - The volume-time plot reveals a good start to the test, a brisk
upstroke to expiration, and a long sustained plateau that all indicate
an adequate effort . The FEV1 is severely reduced (49% predicted), the
FVC is normal, and the FEV1/FVC is low. The flow-volume loop shows a
coved expiratory limb and a normal inspiratory limb. This spirogram
shows severe obstruction (answer 4).