Restrictive Lung Disease Flashcards
What is a broad definition of RLD?
Does this affect inspiration or expiration?
A reduction in lung volume
Makes it hard to inspire
What are the 2 broad categories of RLD?
What does each mean?
Intrinsic = problem is with the lug
Extrinsic = affects the lung indirectly
Give some examples of other structures affected in extrinsic RLD?
- pleura
- chest wall
- neuromusculature
What is the name of the graph that details forced expiration?
What are it’s axes?
Forced expiration Spirograph
X = time Y = litres
What is FEV1?
What is FVC?
What is the normal ratio and what is the name of this?
FEV1 = maximal forced expiratory volume in 1 second following maximal inspiration
FVC = maximal forced expiratory volume following maximal inspiration
Ratio = “Forced Expiratory Ratio” = usually 75% in health
What is seen in RLD in respect to the:
1) FEV1
2) FVC
3) FEV1/FVC
1) reduced FEV1 due to not breathing as much in (therefore can not breathe as much out!)
2) reduced FVC (for the same reason)
3) as BOTH reduced the RATIO remains the same or even INCREASES!!
Is gas transfer reduced in RLD?
Depends on the cause…
…if the cause is EXTRINSIC and lung parenchyma disease based then yes, if not then no
Give some examples of RLD.
Lung fibrosis
Respiratory muscle weakness
What happens in intrinsic RLD?
The lung elastic recoil is INCREASED, making it harder to expand
This results in hypoxia due to a V/Q mismatch (V vein reduced)
What happens in extrinsic RLD?
The compliance of the respiratory system is decreases meaning hypoxia occurs again due to a V/Q mismatch (with V reducing) but this time there are areas of atelectasis
What is atelectasis?
Lung collapse
What is diffuse pleural thickening?
What type of RLD is it?
What can cause it?
Thickening of the pleura?
It is EXTRINSIC as it is not affecting the lung directly
It can be caused by:
- Infection (TB)
- asbestosis
What is chest wall disease?
What type of RLD is it?
What can cause it?
Chest wall disease is normally a deformation of the chest wall
It is extrinsic
It can be caused by:
- pectus excavatum
- kyphoscoliosis
What is neuromuscular disease?
What type of RLD is it?
What can cause it?
It is basically a type of paralysis or the muscles and neurovasculature supplying respiration
It is extrinsic RLD
It can be caused by:
- polio
- motor neurone disease
- muscular dystrophy
- myasthenia gravis
What is ILD?
Interstitial lung disease = blanket term for a RANGE of disorders that cause lung fibrosis (scarring/stiffening)
It includes pulmonary fibrosis
Which areas of the lung are affected in ILD?
Distal to the terminal bronchioles (alveoli)
The areas between the aleveoli and the capillary endothelium (interstitium)
What is gas transfer factor?
TLCO = transfer of the lungs CO (carbon monoxide)
Name 3 drugs which can cause ILD?
Amiodarone (anti-arrhythmic)
Nitrofuratoin (bladder infection antibiotic)
Bleomycin (chemotherapy)
What 3 respiratory conditions is clubbing and crackles seen in?
What type of lung disease is each?
Idiopathic pulmonary fibrosis (finer crackles) = ILD (restrictive)
Bronchiectasis (courser crackles) = widened airways and excess mucous = obstructive lung disease
Cystic fibrosis (course crackles) = obstructive lung disease
What does TLCO tell you about a lung condition?
If the problem is intrinsic or extrinsic to the lungs
If TLCO reduces = INTRINSIC problem (with lungs)
If TLCO NOT reduces = EXTRINSIC problem (not lungs e.g. chest wall deformity)
What is another name for idiopathic pulmonary fibrosis, which is also its pathology?
Usual interstitial pneumonia
Who are the group most at risk of IPF?
Males aged 66+
What test is key in ILD?
Why is this?
CT scan
Diagnosis is by this method +/- biopsy
What tests are used in ILD to identify the:
1) severity
2) prognosis
1) severity = lung function tests (VC, TLCO)
2) prognosis = exercise tests
