Restrictive Lung Diseases Flashcards
In general, what happens to lung volume in restrictive diseases
it is reduced
when considering restrictive diseases, what is our broad definition - location in lung and pathologic process
inflammatory dz of the lower respiratory tract (alveolar dz) - fibrosis
what do we see on CXR for restrictive lung dz
reduction in lung volume - see the diaphragms elevated
define intrinsic restriction and provide example
restriction due to alterations in lung - interstitial fibrosis
define extrinsic restriction
restriction due to alterations in surrounding structure
there are 2 types of intrinsic lung disorders causing restriction. In addition to interstitial lung dz, what is the other?
resection of the lung tissue
(pathoma) - what is the PFT definition of restrictive dz (3 things)
1) dec FEV1
2) greater dec FVC
3) inc FEV1/FVC ratio
for extrinsic disorders causing restriction of lung, what are the 3 main categories?
1) dz of pleura
2) dz of chest wall
3) neuromuscular disorders
for interstitial lung dz, what is the predominantly affected component (1) of what structure (2)
1) connective tissue
2) alveolar wall
ILD affects 2 things - lung volume and diffusion capacity. what is the most important determinant of diffusion capacity?
surface area
Thus in ILD, volume is dec, so surface area is dec, and diffusion capcity is dec
what happens to expiratory airflow in ILD
it is not affected; this is not an obstructive disorder
Compare the percentages of macrophage, lymphocyte, and neurophil in lung vs peripheral blood (just most common to least common)
blood - neutrophils, lymphocytes, then monocytes
Lung - macrophages, lymphocytes, then neutrophils least common
comparing the two etiologies of restrictive ILD, granulomatous and nongranulomatous, which one is more lethal, i.e. more fibrotic
nongranulomatous is more fibrotic, and thus more lethal
granulomas are still reversible, thus less fibrotic
if you see nongranulomatous ILD, what should be your first thought as to cause of the ILD?
look at medications pt may be taking
what 3 drugs should you be worried about in pt w/ nongranulomatous ILD
1) amiodarone - one of most common anti-arrhythmic drugs (MUST KNOW)
2) Bleomycin
3) nitrofurantion
what form of therapy, not a drug, can cause nongranulomatous ILD?
external radiation
if you do not know the etiology of the ILD fibrosis, and you see granulomas, what is the the dx
sarcoidosis - it is a dx of exclusion
If you do not know the etiology of the ILD and you do not see granulomas (nongranulomatous), what are the two broad categories of causes
1) Idiopathic interstitial penumonias
2) ILD w/ connective tissue diseases
what are 4 environmental causes of ILD fibrosis?
1) asbestos fibers
2) coal dust
3) cotton dust
4) pigeon droppings
the hypoxemia of ILD is mostly due to what?
V/Q mismatch - V is decreased compared to Q
what is the CO2 status of a patient with ILD? and why?
ILD - hypocapnia due to hyperventilation
what happens to the A-a gradient in ILD
A-a gradient increases
what is the hallmark finding of ILD (regarding oxygen status)
Exercise induced hypoxemia
says could be on exam
Define exercise induced hypoxemia in terms of A-a gradient
A-a gradient is normal at rest, but it increases during exercise
PFT in ILD - what are hallmark findings
1) TLC
2) VC
3) diffusing capacity
4) expiratory airflow
1) reduced TLC
2) reduced VC
3) reduced diffusing capacity
4) normal expiratory airflow
again, recall the definition of restrictive lung dz in terms of FEV1, FVC, and FEV1/FVC ratio
FEV1 is dec
FVC is dec even more
FEV1/FVC is inc
(this might be tested - know how to diff from obstructive dz)
To differentiate obstructive vs restrictive pathology, what values do we look for in the FEV1/FVC ratio for each (ranges)
obstructive - FEV1/FVC less than 70
restrictive - FEV1/FVC greater than 80
what is the most common symptom of ILD?
dyspnea
what are the common clinical signs of ILD?
1) breathing pattern
2) auscultation of lungs
3) inspection of PVD
4) heart pathology
5) oxygen status
1) tachypnea
2) crackles “velcro” rales
3) digital clubbing
4) cor-pulmonale, late
5) cyanosis, late
what is the buzzword radiologic finding of ILD that suggests end stage lung dz
honeycomb
what is the buzzword radiologic finding of ILD that suggests early-stage lung dz
ground glass
what is the buzzword radiologic finding of ILD that suggests in-between stage lung dz
interstitial markings (reticulo-nodular)
is ground glass appearance reversible?
yes - can be treated
what are the 5 components of diagnosis of ILD
1) extensive history
2) physical exam - evaluate symptoms and signs
3) look at radiographs
4) PFTs
5) BAL and lung biopsy (not necessary every time)
Know about BAL
Muthiah told this guy to talk about it, it must be impt
know that lung resection can cause restrictive pathology
remove part of lung, TLC must decrease, and so on
in what fraction of patients can the dx of restrictive lung disease be made with just PFT and radiology? what fractioin requires lung biopsy?
PFT + radiology - 2/3 of pts
lung biopsy - 1/3
