ICL 2.11: Restrictive Lung Diseases Flashcards
what is restrictive lung disease?
anything that can decrease lung volume! specifically decreased TLC, FVC and FEV1
since everything decreases, FEV1/FVC will be normal, over 0.80
what are the 2 major causes of restrictive lung disease?
- extra-pulmonary causes
- lots of fat around the lungs like obesity
- kyphoscoliosis
- pleural effusion = fluid in the pleura
2. interstitial lung disease = restrictive lung disease secondary to lung disease
what are the effects of extra-pulmonary restrictive lung disease on A-a gradient, residual volume, and DLCO?
normal A-a gradient
normal residual volume
normal DLCO
these are all normal because the restrictive lung disease is being caused by something extra pulmonary, there’s nothing actually wrong with the lung itself
what are the effects of interstitial restrictive lung disease on A-a gradient, residual volume, and DLCO?
increased A-a gradient
decreased residual volume
decreased DLCO
what conditions can cause extrapulmonary restrictive lung disease?
- poliomyelitis
- myasthenia gravis
- obesity
- scoliosis
what conditions can cause interstitial restrictive lung disease?
- collagen vascular disease
- sarcoidosis
- pneumoconiosis (asbestosis, coal miner, silicosis)
- hypersensitivity pneumonitis
- drug toxicity
- idiopathic
what is interstitium?
the connective tissue framework of the lung!
the secondary pulmonary lobule is the most important part of the interstitium because it has lymphatics which clean stuff up which is why when you have interstitial restrictive pulmonary disease you’re in big trouble if you get an infection and the pneumonia will last longer and be more severe without the lymphatics around to clean stuff up
what is the secondary pulmonary lobule?
part of the interstitum: a unit of the lung supplied by 3-5 terminal bronchioles
it has airways, pulmonary arteries, veins and lymphatics
lymphatics clean debris and pus like when there’s pneumonia
when there’s interstitial lung disease, this part of the lung is damaged which is bad because it’s what cleans up infections and without it you’re screwed and very susceptible to infections
what are interstitial lung diseases?
disease of the connective tissue framework of the lung
it will effect the interlobular septae
what are airspace diseases?
diseases that affect the terminal airspaces = alveoli!
the alveoli can be filled with pus, blood, edema, cells –> the gas in the alveoli is replaced by another substance!
this will cause white infiltrates on CXR
how do we physiologically measure the abnormalities in interstitial lung disease?
check the diffusing capacity for carbon monoxide (DLCO)
the expectation is that it’ll be at least 80% of what’s predicted for that specific patient
you ask the patient to breath in CO and then ask them to hold their breath for 10 seconds to allow for diffusion and then you measure the amount of diffusion
this tells you the ability of the lungs to transfer gas across the alveolar-capillary membrane to RBCs –> you need to know your Hb levels because they can skew the results
how does DLCO differentiate extrapulmonary vs pulmonary restrictive lung disease?
if you have extrapulmonary restrictive lung disease you’ll have a normal DLCO because there’s nothing wrong with the lung itself
but if you have interstitial lung disease you’ll have decreased DLCO!
what is ground glass opacity?
hazey looking lungs but you can still see through it so it doesn’t obscure underlying vessels
the lungs just look a little cloudy white
this tells us there’s alveolitis or early fluid buildup that’s not totally filling the alveoli yet
you see this with interstitial diseases
what is honey combing on CT?
late stage lung fibrosis
honey comb fibrosis is very extensive and can cause traction bronchiectasis = they’re pulled open by the fibrosis causing the honey comb appearance!
what is tree in the bud appearance on a CT?
when the bronchioles are obstructed with pus! the CT literally looks like tree branches with buds
so it’s associated with bronchiolar infection like infectious brochiolitis
ex. mycobacterium, staph, etc.
what testing do you do if you suspect interstitial lung disease?
if someone comes in with SOB and you do a CXR that isn’t that sensitive but you hear crackles so next you should:
- high resolution CT
- physiologic testing (DLCO and PFT; RV will be decreased)
- bronchoalveolar lavage (BAL)
- surgical biopsy
what is the investigation of choice for detection and characterization of interstitial lung disease?
high resolution CT scan is the most sensitive and specific
MRI is only used for abnormalities in the apex of the lungs where we want to see the involvement of the brachial plexus like with a Pancost tumor
CXR aren’t very sensitive
ventilations perfusion scans are for chronic thromboembolic disease
what is the physiologic response of the lungs to interstitial lung disease?
- restrictive pattern (decreased FVC)
2. impaired gas exchange (decreased DLCO)
pulmonary funciton abnormalities in interstitial lung diseases include all of the following except?
A. reduced vital capacity
B. reduced FEV1/FVC
C. reduced diffusion capacity
D. reduced total lung capacity
B. reduced FEV1/FVC
because all the values are proportionally reduced so this ratio won’t change and it’ll still be over 0.8
which conditions are collagen vascular disease ILD?
- scleroderma
- polymyositis-dermatomyositis
- SLE
- RA
- mixed connective tissue disease
- ankylosing spondylitis
what is rheumatoid arthritis?
disease of the joints that effects women more than men but when it comes to the lungs it effects male lungs more
can cause collagen vascular disease ILD!
high titers of RF and rheumatoid nodules will be present
what is scleroderma?
disease that can cause collagen vascular disease ILD
associated with honeycombing with traction bronchiectasis
scleroderma can also cause esophagus dilation which causes aspiration!!
what is sarcoidosis?
asystemicdiseasecharacterize bythepresenceofnoncaseatinggranulomasthat is systemic so it can literally effect any organ but most commonly the skin, liver and lungs
sarcoidosistypicallyaffectsyoungadults,butitcanaffectanyindividualatanyage.
theexactetiologyisunknown….
itmostcommonlyaffectsthepulmonarysystem,initialpulmonarysymptomssuchascough
afterpulmonaryinvolvement,theeyesandskinarethenextmostcommonlyinvolvedsystems
what is the pathologenesis of sarcoidosis?
the hallmarkofsarcoidosisisthepresenceofnoncaseatinggranulomasinaffectedorgans
thesegranulomasformbecauseofwidespreadactivationofCD4+/CD8+Tcellsandthereleaseofpro‐inflammatorycytokinesbyTh1CD4+Tcells
thereleaseofinterferon(IFN)‐γfromCD4+Tcells activatesmacrophages which thenproducetumornecrosisfactor(TNF)‐αthatmaintainsthegranulomas
the activated macrophages withinthesegranulomasproduceangiotensinconvertingenzyme(ACE),someasuring serumACElevelsisapartofthework‐upforsarcoidosis however, it’s NOT specific
what is the clinical presentation of pulmonary sarcoidosis?
- young adults
- cough
- SOB
- chest pain
- decreased total lung capacity
- normal FEV1/FVC
- CXR: bilateral hilar adenopathy and reticular opacities
patients are often found to have interstitial lung disease
what is Lofgren syndrome?
a specific acute clinical presentation of sarcoidosis, consisting of a classic triad:
fever + bilateral symmetrical hilar lymphadenopathy + erythema nodosum
what is the clinical presentation of the various organs that can be effected by sarcoidosis?
- skin lupus like rash
- messed up pupil
- nerves = Bells palsy
- lung nodules
lung, skin, liver and eyes are most effected
what is the prognosis for pulmonary sarcoidosis? how do you treat it?
steroids!
they act as immunosuppressants and are the DOC for sarcoidosis
70% of patients will have total remission, 20% will have some permanent loss of lung function
10% will die due to cardiac dysfunction due to AV block, CNS disease, or pulmonary fibrosis leading to cor pulmonale
A 24-year-old African American male applies for work in a steel mill. He has a negative health history and a normal review of systems. A routine CXR is performed and shows bilateral adenopathy
A. order a contrasted CT of the chest, abdomen, and pelvis
B. clear to start work on Monday
C. collect 3 sputum samples for acid-fast smears and cultures, and send one sample for Mycobacterium tuberculosis nucleic acid amplification
D. order high-resolution CT scan of the chest without contrast
E. start prednisone 60 mg daily
no crackles and totally normal CXR except for hilarity adenopathy so he can go back to work! he has no physiological disease
not all cases of sarcoidosis need to be treated unless there’s organ involvement or symptoms; then you’d give steroids
what is pneumoconiosis?
aninterstitiallungdisease
resultingfroman inflammatoryresponsethat
occurswhencertaintypesofdust particlesareinhaled
it’s an occupational and environmental lung disease caused by exposure
common ones are coalminers disease, silicosis and asbestos related diseases
inhalationofwhatsizedparticlesismostlikelytoleadtothe developmentofpneumoconiosis?
inhalationofparticlesthatare1‐5µmindiameterismostlikelyto leadtothedevelopmentofpneumoconiosis
the smaller the particle the deeper down into the lung the particles can get
what is the pathogenesis of pneumoconiosis?
chronic exposure to small particles 1‐5µm that get deep down into the lungs and the immunological response causes inflammation which damages the lungs over time
what is the most helpful tool in the diagnostic workup of someone with suspected pneumoconiosis?
employment details and exposure history!!
- job
- type of industry
- years employed
- materials used by workers
- hygiene of workplace
- ventilation/exhaust system
- use of protection
what is coal miner’s lung?
a type of pneumoconiosis
coal is an inert dust BUT extended exposure over the course of many years causes pneumoconiosis to develop
prolongedexposuretocoalleadstopulmonarymacrophagesbecomingfilledwithcarbon,knownascarbon‐ladenmacrophages
CXR ofapatientwithcoalworkers’pneumoconiosiswillshowthatbothoftheupperlobes havebeenaffected because upper lobes have the highest ventilation
whatisthehistologichallmarkinapatientwithcoalworkers’ pneumoconiosis?
carbon‐ladenmacrophagesisthe
histologic hallmarkofcoalworkers’
pneumoconiosis
what is silicosis?
a pneumoconiosis that results from the inhalation of silica dust
patients usually have h/o working in foundries as sand blasters or in mines
what are patients with silicosis at risk for?
tuberculosis!
today it’s HIV is the highest risk for tuberculosis but in south africa, it’s silicosis!
silicosis also increases your list for lung cancer
what is the imagining hallmark of silicosis?
“eggshell”calcificationsareseeninthehilarlymphnodesofthechest
silicosisisknown toaffecttheupperlobesofthelungs
what are the risk factors for silicosis?
- mining
- stone cutting
- road and building construction
4 .glass manufacturing
- sand blasting
- sculpting or glass blowing
what is Caplan syndrome?
RA + pneumoconiosis of any type
cough, SOB, features of RA like painful joints and morning stiffness
what is asbestos?
asbestos refers to six naturally occurring fibrous minerals that have the ability to resist heat, fire and electricity
SO much industrial stuff used to use asbestos because it’s heat proof!
what is asbestosis?
a chronic, progressive form of parenchymal interstitial fibrosis caused by long term asbestos exposure that usually effects the lower lobes
lungs will have pleural plaques
increased risk for malignant mesothelioma
increased risk for lung cancer
patients will often have h/o working in shipbuilding, roofing, or plumbing industries
what is a common CXR finding of a patient with asbestosis?
- pleural effusions
2. subdiaphragmatic pleural plaques
what is the treatment for pneumoconiosis?
it can’t be cured…
progression can be slowed though with treatment
most importantly, avoid exposure to the offending agent and take preventative measures like quit smoking and wear PPE
what is mesothelioma?
this aggressive cancer forms in the thin membrane (mesothelium) that protects vital organs in the chest and abdomen
exposure to asbestos is the only medically-verified cause of the disease
what is hypersensitivity pneumonitis?
an inflammatory lung disease caused by an immunologic response to inhaled environmental exposures
it’s a type III and IV hypersensitivity reaction
can be caused by fungi, bacteria, animal products, bird poop, and chemicals –> the most common is thermophilic actinomycetes which is associated with cool mist humidifiers
it will cause noncaseating granulomas that will result in interstitial lung disease
what are the acute clinical findings seen with hypersensitivity pneumonitis?
- abrupt onset = 4-6 hours following exposure
- fevers, chills, malaise, nausea, cough, chest tightness, dyspnea without wheezing
can be confused with oral or bacterial infection so patients are frequently treated with antibiotics initially
what are the chronic clinical findings seen with hypersensitivity pneumonitis?
continued exposure to triggers
you might not always have a history of acute episodes to lead you in the right direction
but patients will often report insidious onset of cough, dyspnea, fatigue and weight loss
maybe try to ask about their history of where they work, if they have birds, etc.
how do you treat hypersensitivity pneumonitis?
avoid the antigen!!
systemic steroids can be given to help with short-term recovery from symptoms
what is idiopathic pulmonary fibrosis?
chronic, progressive disorder leading to fibrosis/scarring of the lower respiratory tract
you’ll see irregular reticular opacities and traction bronchiectasis that will appear as honeycombing on CT
2-5 year survival
it’s a restrictive disease so FEV1/FVC will be above 0.8
how do you treat idiopathic pulmonary fibrosis?
- supportive care like oxygen
- vaccination against pneumococcal and influenza
- lung transplant is the only definitive treatment
no medication can cure IPF but there’s 2 medications that slow progression: nintedanib and pirfenidone
which drugs are toxic to the lungs?
- nitrofurantoin (antibiotic)
- amiodarone (anti arrhythmic)
- gold (anti-inflammatory)
- bleomycin (chemo)
- radiation
