QuestionSBA
QuestionChoice
This is where there is a reduction in the volume of air the lungs can hold, this is often due to the loss of elasticity of the alveoli.

The speed of airflow out of the lungs is not impaired so FVC is reduced and FEV1 is relatively preserved.

This produces a ratio > 70% also known as a restrictive picture. Conditions that cause this include fibrosis/ scarring of the lungs or a pleural effusion.
10005827
b
FEV1/FVC ratio 85%
QuestionChoice
This would support the restrictive spirometry picture.

The diagnosis of asthma would result in an obstructive spirometry finding.
10005830
e
FVC is reduced, FEV1 is preserved
QuestionChoice
Restrictive lung conditions can cause an increased FEV1/FVC ratio or can present with a normal ratio with a decreased FVC.

This is because FVC will be reduced with fibrotic or other pathological changes and FEV1 can be preserved. With worsening disease, FEV1 can decraese also and cause a normal ratio.
10005828
c
FEV1/FVC ratio 70% with decreased FVC
QuestionChoice
The likely diagnosis, in this case, is asthma. This is because the patient has a past medical history of atopy (eczema and hayfever) and the symptoms are highly suggestive.

Spirometry measures forced vital capacity and forced expiratory volume in one second. The normal ratio is about 70%.

In asthma, there is an increase in airway resistance due to secretions and bronchospasm and therefore expiratory flow is reduced. FVC is likely to be normal or slightly low due to air trapping but FEV1 is reduced as airway flow out is not as quick. This results in a ratio of <70%, this can be interpreted as an obstructive lung condition.
10005826
a
FEV1/FVC ratio 60%
QuestionChoice
Spirometry can be normal in well-managed asthma but this is the first presentation for this symptomatic patient so is not likely.
10005829
d
FEV1/FVC 70%
Concept
Chapter
2693
3726
Spirometry
Topic
132
Respiratory
13712
18 year old who has a past medical history of hayfever and eczema presents with a night-time cough, wheezing, shortness of breath and exercise intolerance.

What is most likely to be seen on spirometry with the most likely diagnosis?
a