Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
|
Serpentine fiber characteristics
|
Chrysotile
Long, pliable curley fibers Readily cleared from the lung Mesothelioma risk by itself or with tremolite contamination |
|
|
Amphiboles fiber characteristics
|
Tremolite, amosite crocidolite
Short, straight, needle-like More durable & fibrogenic Greater mesthelioma risk Readily form asbestos bodies |
|
|
Ferruginous body
|
Asbestos fibers covered in protein and then iron
Only visible with iron stains Abundance of ferruginous bodies does not correlate to amount of asbestos in lungs -Huge diversity in rate of coating |
|
|
Asbestos exposure
|
>3000 products
40% of the workforce from 1940-1970 key to Dx is complete history and high index of suspicion |
|
|
Materials and industries with asbestos exposure
|
MATERIALS
Textiles Building materials Plastics Paper products Insulation Caulks, putties cements, bond refractories INDUSTRIES Pipefitting Plumbing Foundry Construction Printers Carpenters Railroad Shipyards |
|
|
Asbestos latency
|
Must be >10 years
Longer the better therefore early jobs most important |
|
|
Asbestos induced pleural effusion
|
May develop > 10yrs after first exposure
May be benign or malignant May be bloody Can lead to blunting of costophrenic angle through pleural thickening |
|
|
Asbestosis pleural plaques
|
Parietal pleura
-inside chest wall Posterior-lateral surface 6-9th ribs Usually bilateral Solitary abn. in 48% of workers 20 yr latency usual |
|
|
Asbestosis
|
ILD
Fine reticular nodular markings Starts in the lung bases Latency often >20yrs Dose dependent |
|
|
Mesothelioma: exposure history, latency, risk, types
|
Exposure Hx in 70-80%
30-40 yr latency Risk NOT dose dependent 3 types -Epithelial -Sarcomatous -Desmoplastic |
|
|
ILO score
|
Measures severity of scaring in the lungs
0 nothing 1 mild scarring 2 moderate scarring 3 severe scarring B reader (specialist at reading films) give 2 scores. First is what he thinks it is. Second is what he thinks another B reader might give it. Elevated in smokers performing same job as non-smokers |
|
|
Mesothelioma: signs and symptoms
|
Bloody pleural effusion
Cytology rarely Dx (biopsy usually required) Symptoms -Pleuritic CP 60% -Dyspnea 35% -Cough 15% -Weight loss 5% |
|
|
Bronchogenic cancer and exposure
|
Asbestos related cancer
5 X more common than in non exposed Synergy with cigarette smoking yields 100 X risk Cell types equal to smoking induced Loosely exposure amount related Most common cancer caused by asbestos exposure |
|
|
Occupational asthma definition
|
"Variable airways narrowing causally related to exposure in the working environment to airborne dusts, gases, vapors or fumes"
It is specific to the work place |
|
|
Occupational asthma: epidemiology and prevalence in industries
|
Occupational exposures cause significant worsening in up to 15% of asthmatics
Estimated 2-5% of asthma cases in U.S. are de novo occupational asthma Failure to diagnose and manage promptly can lead to long-term, irreversible sequelae Plastics industry 5% Animal breeders/handlers 6% Bakers 10-30% Cotton workers (cardroom) 20-30% Metal refinery (platinum) 30-50% Western red cedar 5% |
|
|
History suggesting non-occupational asthma
|
No relation between work and symptoms
Preexisting asthma / respiratory problems Upper respiratory infection at onset of symptoms Non-occupational allergies Smoking Medications (beta blockers, NSAIDs) Gastroesophageal reflux symptoms Review medical records |
|
|
Occupational asthma: immunology
|
Latent period of immunologic sensitization
Low levels cause symptoms Sensitivity increases with continued exposure If IgE mediated, correlation with skin tests, in vivo tests Usually only in minority of workers |
|
|
Occupational asthma: exposure causing asthma (not just exacerbating it)
|
TDI (diisocyanates) 5-10%, wood dusts 4%, pine resins (colophony) 4-21%, salts of nickel chromiun & platinum
RADS (denudation of respiratory tract epithelium, respiratory failure) -acute overwhelming exposure -nonspecific bronchial hyperreactivity --methacholine |
|
|
Reactive Airways Dysfunction Syndrome (RADS)
|
No previous history of asthma
Acute, high level exposure to toxic/irritant agent Respiratory symptoms within 24 hours of exposure Persistent respiratory symptoms, non-specific bronchial hyperreactivity Pulmonary functions normal or show reversible obstruction -Obstruction less reversible than asthma Eosinophilic infiltration not characteristic |
|
|
Occupational asthma challenge diagnosis
|
A positive challenge is usually defined by a sustained fall in FEV1 of ≥ 20%, as compared to the control mock day.
-This confirms the diagnosis of occupational asthma A negative challenge however does not exclude entirely the diagnosis of occupational asthma -Wrong agent (or sensitizing process not active) -Loss of sensitization -Medication not allowed |
|
|
Occupational asthma management
|
Reduce / avoid exposure in work place
Removal of worker in some cases, particularly if sensitizer present Surveillance measures -Periodic monitoring of work place exposures, spirometry, tests for immunologic sensitization Medications Address any non-occupational factors |
|
|
Occupational asthma prognosis
|
Timely removal should result in improvement
Residual disease -Reported from isocyanates, red cedar, snow crab, some irritants, other agents -Worse prognosis if greater duration exposure; greater severity / frequency of symptoms, airway obstruction or hyper-reactivity, dual bronchial responses |
|
|
Silicosis occupational exposures
|
Metal mining
Coal mining Nonmetallic minerals Stone, clay and glass products Foundries Sandblasting |
|
|
Silicosis presentation
|
Shortness of breath on exertion
Cough/sputum production Chest tightness Wheezing |
|
|
Silicosis x-ray abnormalities
|
Rounded opacities approximately 1 mm in diameter
Upper lung zones May coalesce or Calcify -into progressive massive fibrosis May have associated lower lung bullae that cause pneumothorax Egg-shell calcification of mediastinal, hilar nodes |
|
|
Silicosis: immunity
|
High incidence of RF and ANA
High incidence of TB or m. Avium Caplan’s Syndrome |
|
|
Silicoproteinosis
|
Acute overwhelming exposure
Prominent alveoler filling with eosinophilic proteinaceous material |
