Occupational health of respiratory disease

Question 1

What are occupational respiratory disorders?

Answer 1

These are disorders affecting the respiratory
tract as a result of workplace exposures.

> These may be caused by an occupational
exposure, or

> These may be aggravated by an occupational
exposure

Question 2

What are the occupational respiratory disorders casued by?

Answer 2

> These may be caused by an occupational
exposure, or

> These may be aggravated by an occupational
exposure

Question 3

What are the categories of the occupational respiratory disorders?

Answer 3

1. Disorders of the airways
2. Disorders of the parenchyma
3. Airway and parenchymal damage
4. Malignant diseases

Question 4

What are the disorders of the airways?

Answer 4

 Asthma
 Chronic bronchitis
 Byssinosis

Question 5

What are the disorders of the parenchyma?

Answer 5

 Idiopathic Pulmonary Fibrosis
 Granulomatous Lung Diseases
 Pneumoconiosis

Question 6

What are the airway and parenchymal damage disorders?

Answer 6

 Acute inhalational injury
 Hypersensitivity Pneumonitis
 Pulmonary Alveolar Proteinosis
 Infectious disease

Question 7

What are the malignant occupational respiratory diseases?

Answer 7

 Lung cancers

 Pleural cancers

Question 8

What is the clinical approach to Occupational respiratory disorders?

Answer 8

1. Interview
2. Clinical examination
3. Investigations and laboratory tests

Question 9

What happens in an interview in clinical approach of occupational respiratory disorders?

Answer 9

you find out the:-

 Nature of the presenting complaints
 Medical History
 Social and family History
 Occupational history

Question 10

What happens in an investigation and lab tests in clinical approach of occupational respiratory disorders?

Answer 10

 Lung function tests
 Radiography
 Skin prick tests
 biopsy

Question 11

What are some common occupational respiratory disorders?

Answer 11

 Occupational Asthma

 Chronic Obstructive Pulmonary Disease

 Pneumoconiosis

 Hypersensitivity pneumonitis

 Acute Inhalational Injuries

Question 12

What is occupational asthma?

Answer 12

It is work related Asthma

 A disease characterized by reversible reduction in airflow or increased airway
irritability due to:-

> causes attributed to a particular working environment

Question 13

What happens in the obstructed airway?

Answer 13

There is inflammation and thick mucus.

Question 14

What are the types of asthma in the workplace?

Answer 14

1. Asthma caused by work
   > Occupational asthma
   > 2-15% of all asthma cases
2. Asthma made worse by work
   >At least 5 in every 100 people have asthma in the
   community

> Not all of these are caused by work (even though
it may have started while working at a particular
factory)

Question 15

Types of asthma caused by work.

Answer 15

1. Delayed onset

> Generally low exposure over months/years
Caused by respiratory sensitizers
“asthma with latency”

2. Immediate onset
   >Generally very high exposure, often requiring
   emergency hospitalization

> Caused by respiratory irritants
“Reactive Airways Dysfunction Syndrome”

Question 16

What are the casues of occupational asthma?

Answer 16

1. Substances of animal origin
2. Substances of non-animal origin (vegetable)
3. Chemical substances

Question 17

Substances of animal origin that cause occupational asthma

Answer 17

 Birds
 Insects
 Laboratory animals
 Sea animals

Question 18

Substances of non-animal origin that cause occupational asthma

Answer 18

 Certain woods (cedar, oak, mahogany) (LMW)

 Flour and grain dust (HMW)

 Latex (HMW)

 Fungi and moulds (LMW)

 Coffee beans (HMW)

Question 19

Chemical substances that cause occupational asthma

Answer 19

 Isocyanates in spray paints
 Some metals
 Some drugs
 Textile dyes

Question 20

What are the risk factors of occupational asthma?

Answer 20

 Levels of exposure to allergen

 Atopy status

 Cigarette smoking:-
> Generally associated with IgE dependent
asthma

 Non specific airway irritability

 Exposure to low levels of respiratory irritants

Question 21

How does the occupational asthma present?

Answer 21

 Few months to few years after being exposed
 Often starts with just a cough (day/night) or
sneezing
 Commonly diagnosed as “acute bronchitis” –
incorrectly
 Initially gets better when away from work
 Later presents as typical asthma: tight chest,
wheezing, shortness of breath especially
when active
 If exposure continues, symptoms present
even when away from work

Question 22

What are the other issues to deal with when dealing with occupational asthma?

Answer 22

 Need to make sure of diagnosis
 Need to decide whether to remove from exposure
 Value of legal exposure limits
 Value of protective equipment
 Need to decide on whether to apply for
compensation

Question 23

COPD and Work exposures

Answer 23

Work-related chronic bronchitis/COPD has been the subject of considerable debate in the scientific literature

 Balance of opinion that work-relatedness does exist

Question 24

What are the Pneumoconioses?

Answer 24

 Silicosis

 Asbestosis

 Coal Workers’ Pneumoconiosis

 Other dust related pneumoconiosis

Question 25

What are the characterisctics of pneumoconioses?

Answer 25

1. INSIDIOUS ONSET (meaning of insidious=proceeding in a gradual, subtle way, but with very harmful effects) 2. Symptoms of breathlessness 3. Chronic cough 4. Minimal clinical features 5. Radiographic changes – interstitial disease 6. Restrictive lung function changes

Question 26

What is Hypersensitivity Pneumonitis?

Answer 26

> A granulomatous, interstitial and alveolar filling lung disease > Results from repeated inhalation and sensitization from a variety of organic dusts and low molecular weight chemical antigen

Question 27

What are some causes of Hypersensitivity Pneumonitis?

Answer 27

1. Bacterial  Thermophilic and non-thermophilic bacteria 2. Fungal  Aspergillus  Cryptosporium  Penicillium 3. Animal proteins  Avian proteins  Wheat weevils 4. Chemicals  Toluene diisocyanates  anhydrides

Question 28

How does Hypersensitivity Pneumonitis present?

Answer 28

1. Latency – 3 weeks to years 2. Temporal relationship is vital clue 3. Exposure history 4. Acute illness 4 – 12 hours following exposure: > Cough, dyspnoea, chest tightness, fever and chills, myalgia 5. Chronic illness include weight loss, sputum production, fatigue 6. Clinically: bilateral crackles, clubbing, cyanosis

Question 29

What is acute inhalation injury?

Answer 29

 Generally occurs as a result of an accident  Follows a large unpredictable exposure to a respiratory irritant  Most famous example: Bhopal, India

Question 30

Classification of chemical injury

Answer 30

1. Acute – within 48 hours of exposure | 2. Persistent sequelae – weeks to months

Question 31

Chemical injury: Acute – within 48 hours of exposure

Answer 31

 Laryngeal edema  Airflow obstruction  Pneumonia  ARDS

Question 32

Chemical injury: Persistent sequelae – weeks to months

Answer 32

 Asthma  RADS  Bronchitis  Bronchiolitis obliterans

Question 33

Clinical importance of Chemical injury?

Answer 33

 Acute injury – easily recognized and supportive therapy instituted  Delayed onset – may not be recognized and can be fatal or have severe chronic consequences  Some have both acute and delayed onset that may be separated by several weeks  Bronchiolitis obliterans is a common chronic consequence of these disorders

Question 34

What does the Lung function testing include?

Answer 34

 Peak Flow measurements  Basic Spirometry  Cross shift spirometry  Spirometry with bronchodilator response  Non-specific bronchial hyperresponsiveness  Bronchial challenge spirometry

Question 35

What is Spirometry?

Answer 35

Spirometry is an essential clinical tool  Potential for the wide variation in equipment, testing and interpretation  Guidelines provide standardization of testing  Requires procedures and QC check

Question 36

What does spirometry of good quality require?

Answer 36

 Competent operator  Reliable and accurate equipment  Co-operative patient ** Important to focus on technical aspects of test

Question 37

What is Spirometry used for?

Answer 37

 Used for clinical diagnostic purposes  Used for determining work relationship  Used for determining fitness to work and impairment

Question 38

Peak Flow Measurements

Answer 38

 Used to monitor response to medication  Used for diagnostic purposes for occupational asthma: > For the above, need serial peak flow monitoring, 5x per day, for 2 weeks during exposure, and 2 weeks after exposure  Not useful for determining fitness to work or impairment

Question 39

OCCUPATIONAL RESPIRATORY DISORDERS TAKE HOME MESSAGES:-

Answer 39

 Many respiratory conditions may have a work relationship – if not looked for, will not be found  The presentation may be years after exposure has ceased  Prognosis may be dependent on early removal from exposure  Removal from exposure may have financial consequences – therefore careful diagnosis is critical  If work-related – institute process of compensation