Restrictive lung disease Flashcards
Restrictive lung disease
Problem w/ breathing mechanics
Gas diffusion limitation causes decreased lung volumes, increased work of breathing
Inadequate ventilation and/or oxygenation
PFTs:
Decreased total lung capacity
Decreased FEV1 and FVC
Overall FEV1/FVC >= 80%
Conditions with impaired breathing mechanics
Myasthenia gravis Guillain barre sn Poliomyelitis Severe kyphosis Scoliosis Chest wall deformities Morbid obesity Diaphragmatic hernia
Normal A-a gradient
Restrict volume
Interstitial lung dz
Increased A-a gradient
Restricted diffusion
ARDS progression
Shock, infection, toxic gas inhalation, aspiration, high [O2], pancreatitis, heroin OD, sepsis, trauma, uremia, and amniotic fluid embolism
- > inflammatory cells/mediators and oxygen free radicals
- > damage to endothelial (causes pulmonary edema) or alveolar epithelial (type I) cells
- > diffuse alveolar damage (DAD)
- > inflammatory cells/mediators and oxygen free radicals continuing cycle
Neonatal respiratory distress syndrome
Surfactant deficiency – dipalmitoylphosphatidylcholine
-type II pneumocytes mature at 34 weks gestation
deficiency -> increased surface tension -> alveolar collapse
Risks: premature, maternal DM, c-section
Give b-methasone or dexamethasone to mom to mature lungs 48 hrs prior to delivery
O2 toxicity in neonates
Retinopathy of prematurity
Intraventricular hemorrhage
Bronchopulmonary dysplasia
-disruption of development ongoing inflammation
Idiopathic pulmonary fibrosis (cryptogenic fibrosing alveolitis)
Risk: age, smoking, genetics
Mutations: telomerase, mucin MUC5B
Patchy interstitial fibrosis
Median survival after diagnosis 3 yrs
Honeycomb lung on CT
Interstitial pneumonia – heterogenous change of lung, normal mixed w/ honeycombing
Medications causing restrictive lung dz
Bleomycin – pneumonitis w/ infiltrates over 70yo esp
Busulfan – acute lung injury, chronic interstitial fibrosis, alveolar hemorrhage
Amiodarone – pulmonary fibrosis – 1%
Methotrexate – HSR-like lung reaction
Radiation effects on lung
Causes radiation pneumonitis
Restrictive pattern on PFTs
Pulmonary Langerhans Cell histiocytosis
Focal collections of Langerhans cells w/ eosinophils
Eosinophilic granuloma
Birbeck granules – tennis racket shaped
Young adult smokers
Better if stop smoking
Good Pasture Sn
Anti-BM Abs
Lung and kidneys
Hypersensitivity Pneumonitis
Organic dusts -> HSR -> inflammation of aveoli -> acute or chronic dz
Pt hx important
Farmer’s lung – moldy hay Pigeon breeders lung Bird fancier’s dz Cheese washer’s lung Fish meal worker’s lung Mushroom worker’s lung
