Restrictive Lung diseases Flashcards
Different interstitial lung diseases?
- idiopathic pulmonary fibrosis
- sarcoidosis
- radiation induced injury
- pneumoconiosis
What does restriction in lung disorders always mean for the FVC?
- it always means a decrease in lung volume (FVC)
- total lung capacity if measured is significantly reduced
- total lung capacity = FVC + RV
- FEV1 may be reduced
- so ratio of FEV1 to FVC is normal or increased
What is the cause of asbestosis?
- inhalation of asbestos fibers
What are the 2 categories of asbestosis fibers?
- chrysotile and amphibole
- chrysotile is less toxic and accounts for 90% of asbestos use in the U.S.
What are the disease manifestations of asbestosis?
- characterized by slowly progressive (years), diffuse pulmonary fibrosis
- spectrum: asbestosis, pleural dz, and malignancies
- malignancies: non-small cell carcinoma of the lungs - malignant mesothelioma
What is the pathogenesis of asbestosis?
- direct toxic effect of the fibers on pulmonary cells and release of mediators from inflammatory cells
What are the clinical findings of asbestosis?
- most pts are asymptomatic for 20-30 years after initial exposure:
dyspnea on exertion
progresses to fine bibasilar and expiratory crackles and clubbing - if cough, sputum production or wheezing are present more likely secondary to smoking
Dx process of asbestosis?
- PFTs: reduced lung volumes: VC and TLC
decreased pulmonary compliance, and absence of airflow obstruction (normal ratio of FEV1 to FVC) - radiographs: begins in lower lung zones with small parenchymal opacities with a multinodular or reticular pattern
often associated pleural abnormalities, shaggy heart and ground glass appearance
and honeycombing and upper lobe involvement late stage disease
Pathogenesis of Bronchiolitis Obliterans?
- chronic airway rejection in lung transplant pts due to:
episodes of acute rejection, primary graft dysfunction, CMV pneumonitis, noncompliance with immunosuppressive meds and lymphocyte bronchitis or bronchiolitis - can develop farther out from transplant: 5 years after lung transplant 45% of recipients develop BO, this is often a slow, relentless progression
- the mortality rate is 25-56%
What is the presentation of bronchiolitis obliterans?
- usually indolent sxs similar to URI
- exertional dyspnea and decline in spirometry
- initially radiographs and exam only help exclude other illnesses
- advanced stages: see bronchioectasis with obstruction and hyperinflation, often colonized with pseudomonas
Dx of bronchiolitis obliterans?
- requires transbronchial biopsies with BAL:
usually made on a pt who presents with declining spirometry without an acute illness - yield of transbronchial biopsies can be variable
- need a good bronchoscopy technique and adequate bronchio-alveolar lavage
- rule out infection!!
Tx of BO?
- changing anti-immune meds
- photopheresis
- retransplantation
- prevention: make sure pts are taking immunosuppression drugs
What is hypersensitivity pneumonitis also known as?
- extrinsic allergic alveolitis
- it represents an immunologic reaction to an inhaled agent: usually an organic antigen, and occurs within the pulmonary parenchyma
What are the inciting agents of hypersensitivity pneumonitis?
- agricultural dusts
- bioaerosols
- reactive chemical species
Epidemiology of HP?
- ** remains largely unknown and variable: farmer’s lung affects 0.4-7% of the farming population with a prevalence of 420-3000 per 100000 persons
- prevalence of HP in bird fanciers ranges from 20-20000 affected persons per 100000
- cigarette smoking is associated with a decreased risk of HP
- individuals who develop HP have genetic factors that play a role
List of HP etiologic agents?
- farming, vegetable and dairy cattle workers
- ventilation and water related contamination
- bird and poultry handling (exposure to down)
- veterinary work and animal handling
- grain and flour processing and loading (grain can become colonized with microorganisms and insects, grain is easily aerosolized so exposure to antigens can occur easily
- lumbar milling, construction, wood stripping: mold exposure
- plastic manufacturing
- painting
- electronics industry
Presentation of acute HP?
- may follow heavy exposure to antigen
- may be confused with viral or bacterial infection
- abrupt onset (4-6 hrs after exposure) of:
fever and chills
nausea
chest tightness and dyspnea without wheezing - PE: tachypnea and diffuse fine rales
- tx: removal from antigen, sxs subside in 12 hours to several days, disease may recur with re-exposure
- labs: want to order CBC, and white count
CXR: may show a micronodular, interstitial pattern, frequently normal, sometimes do HRCT
Subacute of intermittent HP?
- low level exposure over time: farmers lung or chemical workers
- gradual development of productive cough, dyspnea, fatigue, anorexia, and wt loss
- PE: tachypnea, diffuse rales
- lab: lymphocytosis on BAL, mild hypoxemia
- PFTs: restriction pattern or mixed restriction/obstruction pattern
- x-rays: normal or reticular opacities in middle and upper lung zones, acinar nodules
- Tx: removal from antigen and glucocorticosteroids, takes weeks to months to resolve
Presentation of chronic progressive HP?
- generally no report of acute episodes
- insidious onset of cough, dyspnea, fatigue and wt loss
- PE: digital clubbing may be seen, diff from idiopathic pulmonary fibrosis is difficult
- lab: lymphocytosis, also neutrophilia or eosinophilia on BAL
- PFTs: restrictive, obstructive often seen with it, resting and exertional hypoxemia
- x rays: fibrotic changes, loss of lung volume, emphysema pattern changes (perm. changes)
DDx of HP?
- inhalation fever
- organic dust toxic syndrome
- chronic bronchitis
- asthma
- chronic airflow limitation
How do you dx HP?
- high index of suspicion
- careful review of pts occupational, avocational, and domestic exposures
- a normal CXR doesn’t rule it out
- inhalation challenge by re-exposure
- HRCT and BAL (intermittent or chronic)
Tx of HP?
- antigen avoidance
- glucocorticoids used to accelerate initial recovery, however the long term outcome is relatively unchanged
Prevention of HP?
- reduction of antigenic burden (wetting compost)
- design facilities: maintain humidity less than 60%, avoid having stagnant water or carpet that is likely to get moist
- maintenance: routinely inspect all heating, ventilation, an air conditioning equipment that it is clean and water is drained daily from humidifiers and vaporizers
- protective devices: masks, and filters
What is interstitial lung disease?
- diffuse parenchymal lung disease
- collectively referred to as the ILDs
- a heterogeneous group of disorders that are classified together becuase of similar clinical, x-ray, physiologic or pathologic manifestations
- most of these disorders are associated with extensive alteration of alveolar and airway architecture
Presentation of ILD?
- 50% idiopathic (idiopathic pulmonay fibrosis)
- clinically presents with progressive exertional dyspnea and nonproductive cough
- presents on x-ray with haziness progress to nodules then linear opacities
- prognosis: usually die of respiratory failure within 3-6 years once x-ray changes
Acute restricitve lung disease?
- acute idiopathic pneumonia
- eosinophilic pneumonia
- hypersensitivity pneumonia
- bronchiolitis obliterans organizing pneumonia
Subacute restrictive lung disease?
- sarcoidosis
- some drug induced ILDs
- alveolar hemorrhage syndromes
- conntective tissue disease (SLE)
Chronic restrictive lung disease?
- idiopathic pulmonary fibrosis
- sarcoidosis
- pulmonary langerhans cell histiocytosis
What is Idiopathic pulmonary firbosis? Who does it affect? Rfs?
- chronic, relentlessly progressive fibrotic disorder of the lower respiratory tract
- affects adults older than 40
- precise factors that initiate and maintain inflammatory and fibrotic responses in IPF are unknown
- RFs: infections, enviro pollutants, chronic aspiration, and drugs
IPF pathogenesis?
- early in IPF alveolitis is dominated by inflammatory cells including:
alveolar macrophages - secrete proinflammatory and profibrotic cytokines which affect mesenchymal cell proliferation and promote collagen depositions - neutrophils
- eosinophils
- lymphocytes
- increased numbers of basophils and mast cells
Presentation of IPF? Dx process?
- dyspnea on exertion
- persistent nonproductive cough
- abnormal CXR
Dx:
routine blood tests - including serologic studies and autoimmune testing to r/o other diseases, radiographs, HRCT, PFTs: restrictive pattern, BAL: looking for neutrophils, lymphocytosis - indicates HP
Tx of IPF?
- no randomized placebo-controlled trials show that tx is beneficial
- prognosis of disease is dismal
- uncertainity remains about the following:
which pts should be treated?
when should therapy be started?
what is the best therapy?
how should the disease course and response to tx be monitored?
meds used: glucocorticoids
immunosuppressives: azathiprine, cyclophosphamide, methotrexate
antioxidants: acetylcysteine
What is sarcoidosis?
- a multisystem granulomatous disorder of unknown etiology that affects people worldwide
- characterized pathologically by the presence of noncaseasting granulomas in involved organs
- typically affects young adults, initially presents with one or more of the following:
bilateral hilar lymphadenopathy
pulmonary reticular opacities, skin, joint or eye lesions
What % of pts with sarcoidosis have lung involvement?
- over 90% of pts
- staged according to CXR
Presentaion of sarcoidosis?
- dyspnea
- cough (nonproductive)
- chest pain
Tx of pulmonary sarcoidosis?
- large number of pts undergo spontaneous remission or have benign clinical course
- no easy way to assess dz activity and severity, so predicting clinical course and prognosis of disease is difficult
- marked variability in presentation and clinical course make it difficult to develop tx guidelines
- cause of dz is unknown so no specific tx exists
Indications for tx of pulmonary sarcoidosis?
- worsening pulmonary sx: cough, dyspnea, chest pain, or discomfort, and hemoptysis
- deteriorating lung fxn
- progressive radiographic changes
- tx with glucocorticoids: daily, if improvement slowly taper, if reactivation of disease increase to last effective dose and tx for 3-6 months, some pts require maintenance dose
What is drug induced pulmonary disease?
- eosinophilic pneumonias:
present 2-10 days after drug started, sxs: dry cough, fever, chills, and dyspnea, radiograph: eosinophilic pleural effusion + patchy or diffuse pulmonary infiltrates
What drugs are associated with drug induced pulmonary disease (eosinophilic pneumonia)?
- nitrofurantoin
- sulfonamides
- penicillin
- thiazides
- tricyclic antidepressants
- hydralazine
- isonaizid
- gold salts
tx: withdrawing use of drug
What are the 2 types of radiation-induced lung injury?
- radiation pneumonitis
- radiation fibrosis (long term)
- both are seen in pts who have undergone thoracic radiation for breast, lung, esophageal, stomach cancer and lymphoma
- radiation induced damage dose is limiting factor
Pathogenesis of radiation induced lung injury?
- ionizing radiation localized release of sufficient energy to break strong chemical bonds and generate highly reactive free radical species
- radiation induced lung injury results from the combo of direct cytotoxicity upon normal lung tissue and the development of fibrosis triggered by radiation induced cellular signal transduction
- cytotoxic effect is largely due to DNA damage that causes clonagenic death in normal lung epithelial cells
What factors affect the development of radiation induced lung disease?
- method of irradiation
- volume of lung irradiated
- dosage of radiation
- time dose factor
- concurrent chemo
- induction chemo
Clinical manifestations of radiation induced lung injury? Findings on PE?
- early nonproductive cough
- dyspnea on exertion or inability to take a deep breath
- low grade fever
- chest pain: pleuritic, substernal
- malaise and wt loss may be seen (cancer or radiation caused?)
- PEs:
fine crackles or pleural rub, sometimes normal
**pleural friction rub
dullness to percussion
tachypnea, cyanosis or signs of pulm. HTN (severe)
Chest imaging for DDX? findings on CXR?
- need to distinguish from other pulmonary dz: infection lymphagitic or direct extension of tumor drug induced pneumonitis hemorrhage cardiogenic edema
CXR: may be normal, patchy alveolar filling defects, straight line effect, not conforming to anatomical units but to confines of radiation port is dx (straight lines in radiation field)
- small pleural effusions
Tx of radiation induced lung injury?
- corticosteroids
- inhibition of collagen synthesis
- stop radiation
What is pneumoconiosis?
- nonneoplastic reaction of lung to inhaled mineral or organic dust
- examples: silicosis, coal workers, can be complicated by infection and smoking
Presentation of coal worker’s pneumoconiosis?
- asymptomatic
- may cause chronic bronchitis and COPD so is then known as industrial bronchitis and is compensable
- radiographically: small opacities can progress to larger opacities and fibrosis