restrictive lung disease Flashcards
restricted breathing mechanics or
capacity to diffuse gases through alveoli restricted → ↓ lung volumes, ↑ work of breathing, inadequate ventilation (O2 into alveoli) and/or oxygenation (O2 to blood)
restrictive lung disease
hallmark sign of restrictive lung disease
↓ lung volume
restrictive lung diseases that interfere with breathing mechanics or gas diffusion
1) muscular (normal A-a gradient): myasthenia gravis GBS polio 2) structural (normal A-a gradient): restrict ability of lung to expand and volume of air into lung severe kyphosis scoliosis chest wall deformities obesity diaphgragmatic hernia 3) interstitial disease (↑A-a gradient, impaired gas diffusion): ARDS pneumoconiosis sarcoidosis etc. pneumonia lung abscesses lung cancer
↑A-a gradient
interstitial lung disease
inability to transport O2 from alveoli to pulmonary capillary
risk factors for acute respiratory distress syndrome (cause severe damage to lungs)
shock infection toxic gas inhalation aspiration high O2 concentration for extended time pancreatitis heroin OD sepsis trauma uremia amniotic fluid embolism
severe lung damage → inflammatory cells/mediators and O2 free radicals → damage to endothelial cells and alveolar epithelial (type I) cells → diffuse alveolar damage (DAD) → viscous cycle of inflammation hard to control
also hyaline membrane disease (HMD) → inflammation causes protein rich fluid leaks into alveoli to form intra-alveolar hyaline membrane→pulm edema → ↓ diffusion capacity of O2 → hypoxia induced damage to cells
also coagulation cascade activation →DIC
acute respiratory distress syndrome
cause: surfactant deficiency →↑ surface tension → alveolar collapse
neonatal respiratory distress syndrome
when are type II pneumocytes mature in neonate
34 wk GA
if delivery
risk of supplemental O2 in newborn
retinopathy of prematurity
risk factors for neonatal respiratory distress syndrome
prematurity
maternal diabetes
Csection
chronic fibrotic disease of lung due to INHALATION of inorganic dusts
damage due to MACROPHAGES: ingest foreign material → release inflammatory factors →fibrosis
pneumoconiosis
inhale carbon: coal dust → alveolar macrophages eat it →accumulate in CT
can be seen in urban dwellers, smokers too
black pigment in lung
ASYMPTOMATIC
anthracosis: mild coal workers pneumoconiosis (CWP)
inhale carbon: coal dust
small fibrotic lung nodules - UPPER LOBES
simple coal workers pneumoconiosis (CWP)
inhale carbon: coal dust
progressive massive fibrosis - UPPER LOBES
complicated coal workers pneumoconiosis (CWP)
inhale asbestos: shipbuilding, roofing, pipe fitting, plumbing (SPOUSE doing laundry from worker may get asbestosis)
inhaled asbestos → LOWER lung or mesothelial layers → macrophages try to clear toxins → chronic inflammation →
localized pleural plaques
interstitial fibrosis
recurrent pleural effusion
asbestosis
gerruginous bodies: golden brown fusiform rods (look like dumbells)
asbestos fibers are coated with iron containing protein material
↑ risk mesothelioma, laryngeal cancer, and lung cancer (squamous cell + adenocarcinoma)
if smoker: greater risk of lung cancer
asbestosis
worker in mining, demolition on concrete, stonecutting, SANDBLASTING
inhaled → macrophages try to clear it → chronic inflammation → fibrosis
UPPER LOBES
silicosis
coal miner is at risk for
coal dust: coal workers’ pneumoconiosis (UPPER)
silica: silicosis (UPPER)
radon
“eggshell” calcification of hilar lymph nodes
silicosis
↑ susceptibility to TB
silicosis: (silicotuberculosis)
silica crystals inhibit macrophages from killing phagocytosed mycobacteria
complication of silicosis
↑ risk TB
2x risk of lung cancer
high-tech electronics: aerospace mannufacturing
cell-mediated immunity → NONCASEATING granuloma (looks like sarcoidosis)
↑ risk lung cancer
berylliosis
lung diseases with noncaseating granuloma
berylliosis
sarcoidosis
bilateral hilar adenopathy
sarcoidosis
occurs if genetic predisposition to ineffective repair of alveolar epithelial cells injured by environemental exposures
2 genetic mutations: telomerase, mucin MUC5B
> 50 yo, survival 3 years
patchy interstitial fibrosis
idiopathic pulmonary fibrosis (cryptogenic fibrosing alveoloitis or usual interstitial pneumonia)
honeycomb lung on CT
idiopathic pulmonary fibrosis:
cystic spaces
focal collections of Langerhan cells accompanied by eosinophilic granulomas
young adult smoker
treatment: stop smoking and improve
pulmonary langerhan cell histiocytosis
Birbeck granules: tennis racket shaped cyto organelles
pulmonary langerhan cell histiocytosis:
in Langerhan cells
anti-basement membrane antibodies
goodpasture syndrome
interstitial lung disease + kidney disease (glomerulonephritis)
goodpasture syndrome
or
granulomatosis with polyangitis (upper airway disease)
triad:
necrotizing granulomas of UPPER and/or LOWER respiratory tract
necrotizing or granulomatous vasculitis mostly in LUNGS + UPPER airways
focal necrotizing glomerulonephritis
granulomatosis with polyangitis (Wegener)
inhalation of organic dusts → inflammation of alveoli examples: farmers lung: inhale moldy hay feathers, feces of birds mushroom
hypersensitivity pneumonitis
restrictive lung disease due to medications
bleomycin: pneumonitis with infiltrates >70 yo
busulfan: acute lung injury, chronic interstitial fibrosis, alveolar hemorrhage
amiodarone: fatal pulmonary fibrosis (check TFT, LFT, and PFT!)
methotrexate: hypersensitivity-lung lung RXN
radiation: radiation pneumonitis
“ground glass” appearance on CXR of infant
neonatal respiratory distress syndrome:
interstitial opacities
