clinical features and management of restrictive lung disease Flashcards
define restriction
forced vital capacity <80% of normal
what is used as a marker of restriction
vital capacity
spirometry is key
what are the causes of restriction
lungs pleura nerve/muscle bone other
lung causes of restriction
interstitial lung disease:
idiopathic pulmonary fibrosis
sarcoidosis
hypersensitivity pneumonitis
pleural causes of restriction
pleural effusion
pneumothorax
pleural thickening e.g. from TB (calcification)
skeletal causes of restriction
kyphoscoliosis
ankylosing spondylitis
thoracoplasty
rib fractures - pain
what is thoracoplasty
TB patients used to have ribs reduced/removed at the top to reduce lung volume in order to treat the TB before abx were developed
TB is aerobic so by reducing the lung volume it reduced the ability of the TB to grow
muscular causes of restriction
amyotrophic lateral sclerosis - neurological cause of restrictive pattern to breathing
sub-diaphragmatic causes of restriction
obesity
pregnancy
is restrictive pattern of lung function always due to lung disease
NO
Where is the interstitium
space between the epithelium of the alveolus and the endothelium of the capillary
1-2 cells thick over which gas exchange occurs
what are interstitial lung diseases
> 200 disease causing thickening of the interstitium and can result in pulmonary fibrosis
top 3 ILDs
sarcoidosis
idiopathic pulmonary fibrosis
hypersensitivity pneumonitis
what is sarcoidosis
multisystem granulomatous disease of unknown cause
histological hallmark is non-caseating granuloma
just because there is a granuloma doesnt mean there is sarcoidosis
what is erythema nodosum
bruising rash
well known association with sarcoidosis
lumps on the shins tend to be sore
where are granulomas found in sarcoidosis
skin lesions
often locate to areas of trauma e.g. scars
who gets sarcoidosis
adults <40
f>m
world-wide
how is sarcoidosis investigated
Hx and exam
CXR
stage I sarcoidosis disease on CXR
nodes only
lymphadenopathy and enlarged blood vessels
stage II sarcoidosis disease on CXR
snowstorm shadowing
nodes and lung parenchymal involvement
stage III sarcoidosis disease
fibrosis
stage IV sarcoidosis disease
wrecked lung
irreversible w/o transplant
how is sarcoidosis investigated
pulmonary function tests - can’t be done in isolation
bloods - lower lymphocyte conc in peripheral blood, concentrated in lungs
urinalysis - check for protein or blood, differentiate from vasculitis
ECG - cardiac sarcoidosis can be fatal
TB skin test - granulomas can also be TB
eye exam - check for posterior uveitis, anterior uveitis is bright red
why are smokers less likely to get sarcoid
suppression of lymphocyte response
further assessments for sarcoidosis
bronchoscopy including transbronchial biopsies and endobronchial ultrasound
granulomas can be seen
high res CT - snowstorm, tend to grow along lymphatics
surgical biopsies
mediastinoscopy
video assissted thoracoscopic lung biopsy (VATS)
fairly rare, EBUS is more commonly used
may need to take out a node/piece of lung
how does CXR affect prognosis of sarcoidosis (remission rate)
stage I 55-90%, enlarged glands - 90% chance of spontaneous resolution
stage II 40-70%
stage III 10-20%
stage IV 0%
how is sarcoidosis treated
mild disease, no vital organ involvement, normal lung function, few symptoms - no treatment
erythema nodosum/arthralgia - NSAIDs
skin lesions/anterior uveitis/cough - topical steroids
cardiac, neurological, eye disease not responding to topical Rx, hypercalcaemia - systemic steroids
what is the prognosis for sarcoidosis
<1% of caucasians die
10-205 sustain permanent pulmonary or extra-pulmonary complications
respiratory: progressive resp failure, bronchiectasis, aspergilloma, haemoptysis, pnuemothorax
what is the main histological feature of idiopathic pulmonary fibrosis
fibroblastic focus
these areas produce collagen
typical presentation of IPF
chronic SOB and cough
typically 60-70y/o
m>f
failed treatment for ‘LVF’ or infection
clubbed (40%) and crackles (can be fluid, infection or fibrosis)
appearance of IPF of CXR
fluffy white shadowing at the lung bases
no sharp heart border, fluffy and merges with the lung
appearance of IPF on CT
honeycombing round the edge of the lungs
tends to start at the edge and move inwards gradually
median survival for IPF
3 yrs
treatment for IPF
refer to ILD clinic
oral anti-fibrotic (OAF) - pirfenidone, nintedanib
palliative care
drugs slow down disease progression, don’t improve QOL (can be quite toxic)
surgical option = transplant (best option for <65 y/o)
hypersensitivity pnuemonitis causes
birds
farming
malt whiskey
hx is important - make sure not to miss any potential exposures
