Restrictive Lung diseases Flashcards
1
Q
Different interstitial lung diseases?
A
- idiopathic pulmonary fibrosis
- sarcoidosis
- radiation induced injury
- pneumoconiosis
2
Q
What does restriction in lung disorders always mean for the FVC?
A
- 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
3
Q
What is the cause of asbestosis?
A
- inhalation of asbestos fibers
4
Q
What are the 2 categories of asbestosis fibers?
A
- chrysotile and amphibole
- chrysotile is less toxic and accounts for 90% of asbestos use in the U.S.
5
Q
What are the disease manifestations of asbestosis?
A
- characterized by slowly progressive (years), diffuse pulmonary fibrosis
- spectrum: asbestosis, pleural dz, and malignancies
- malignancies: non-small cell carcinoma of the lungs - malignant mesothelioma
6
Q
What is the pathogenesis of asbestosis?
A
- direct toxic effect of the fibers on pulmonary cells and release of mediators from inflammatory cells
7
Q
What are the clinical findings of asbestosis?
A
- 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
8
Q
Dx process of asbestosis?
A
- 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
9
Q
Pathogenesis of Bronchiolitis Obliterans?
A
- 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%
10
Q
What is the presentation of bronchiolitis obliterans?
A
- 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
11
Q
Dx of bronchiolitis obliterans?
A
- 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!!
12
Q
Tx of BO?
A
- changing anti-immune meds
- photopheresis
- retransplantation
- prevention: make sure pts are taking immunosuppression drugs
13
Q
What is hypersensitivity pneumonitis also known as?
A
- extrinsic allergic alveolitis
- it represents an immunologic reaction to an inhaled agent: usually an organic antigen, and occurs within the pulmonary parenchyma
14
Q
What are the inciting agents of hypersensitivity pneumonitis?
A
- agricultural dusts
- bioaerosols
- reactive chemical species
15
Q
Epidemiology of HP?
A
- ** 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
16
Q
List of HP etiologic agents?
A
- 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
17
Q
Presentation of acute HP?
A
- 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
18
Q
Subacute of intermittent HP?
A
- 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
