Basic Concepts in Occupational Medicine
description
Transcript of Basic Concepts in Occupational Medicine
Occupational Health UnitOccupational Health UnitRoyal Free HospitalRoyal Free Hospital
Basic Concepts in Occupational Medicine
Aims & Objectives
Aim:To be able to apply the basic principles of occupational medicine to your
professional practice as doctors
Objectives:1. Know what questions to ask in order to take an appropriate and relevant
occupational history2. Identify factors or patterns in a patient’s history that may indicate a work related
contribution to ill health3. Consider a work related health dilemma and reach a conclusion with reasons4. List 3 causative agents and related work activities for occupational asthma,
allergic contact dermatitis and cancer.5. Specify what information is necessary to make a fully informed assessment of
an individual’s medical fitness for work
Occupational Health
Work Health (occupational disease/work related ill health)
Health Work (medical fitness for work)
Occupational Health/Therapy
Occupational Medicine/Health
a branch of medicine concerned with the interaction between health and work (“occupation”)
Occupational Therapyassessment & treatment
to enable maximum independent function in daily living, using purposeful activity (“occupation”)
Case 1: The Hazards of WorkYou are an occupational physician. A 31-year-old laboratory technician is referred to your clinic by her manager, because of alleged lateness
and poor performance at work. You are asked to assess whether there is an underlying medical cause for this.
She tells you that she has not been sleeping well lately, possibly due to nocturnal coughing. She says the
lab is cold and drafty, and that by the end of the working day her right arm is aching. She says that when she told her manager, he was unsympathetic; telling her she should leave if she doesn’t like the job.
1. What are the presenting medical problems? 2. What are the possible work-related causes of her symptoms? 3. What are the potential hazards in her workplace and how might you classify them? 4. How will you respond to the manager’s questions?
Classification of work hazards
PhysicalMechanicalChemicalBiologicalPsychosocial
Hazard and Risk
Hazard: potentially harmful
Risk: probability of harm(quantifiable as risk assessment)
IdentifyEvaluateControl
– Eliminate– Substitute– Enclose/separate– PPE/vaccinate
Principles of Control of Workplace Hazards
Case 2: Is it work-related?A 58-year-old hospital porter has been off sick for almost a year, with low back pain. He says he injured his back at work. His back
pain has not improved with physiotherapy and analgesia. He has difficulty walking up and down stairs and is breathless on exertion. His occupational history is as follows:
Left school at 15 Had numerous labouring jobs in the construction industry for 20 years or so Worked on a tunnelling project for 18 months Worked as a lorry driver for a brewery for 8 years Worked as a hospital domestic assistant for 2 years Has been employed as a hospital porter for 11 years 1. What occupational hazards might account for his breathlessness? 2. How would you assess whether his symptoms are work related or not? 3. What are the possible causes of his back pain? 4. What advice would you give him? 5. Is he likely to be return to work? 6. What work might he be able to do?
Pathology
Timing of symptoms
Possible causes
Elicit relevant history
Presentation of Occupational Disease
The Occupational History
What is your job? What do you do for a living? What do you do at work? What do you work
with? What is a typical working day?How long? What else?Any known hazards? Anyone else with similar
symptoms?Hobbies? (DIY, pets, gardening, chemicals)
Occupational Asthma
Occupational Asthma Asthma induced by specific substances
encountered in the work place. It may occur in individuals who would otherwise not have developed asthma
Work-related Asthma Asthma which relates to substances in the work
place (resp irritants) that exacerbate asthma in people with pre-existing asthma
Causes of Occupational Asthma
Isocynates Platinum salts Proteolytic enzymes Wood dusts Glutaraldehyde Soya bean Persulphates or henna Crustaceans or fish
products
Grain / Flour (barley, oats, wheat, maize)
Caster bean dust Laboratory animals Antibiotics Latex Soldering flux (colophony) Ispaghula Tea dust
KOH 2006
exposure
risk
Dose response relationship
UK detergent factory: incidence of occupational asthma vs enzyme use
0
2
4
6
8
10
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
% all cohort
incidence
UK detergent factory: incidence of occupational asthma vs enzyme use
0
2
4
6
8
10
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
% all cohort
40
45
50
55
60
65
70
75
80ktonnes enzyme
enzyme incidence
UK detergent factory: incidence and new employees
0
2
4
6
8
10
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
% all cohort
0
50
100
150
200new employees
new employees incidence
UK detergent factory: incidence among new employees vs enzyme use
0
5
10
15
20
25
30
35
40
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
ktonnes enzyme
40
45
50
55
60
65
70
75
80% new employees
enzyme (ktonnes) incidence (new)
Investigation of a case of suspected Occupational Asthma
History Symptoms Associated symptoms Duration Work history Is patient aware of exposure to any respiratory sensitisers at
work? Timing of symptoms (immediate /delayed) Improvement away from work Adult onset Smoking history History of atopy
Investigation of a case of suspected Occupational Asthma
Clinical investigations 2hrly PEFR Skin prick test RAST / ELISA Spirometry Bronchial challenge
Management
1. Drug treatment • as for non-occupational asthma
2. Non-drug treatment • Remove from exposure • Review work place
– Is prevention possible?– Are control measures adequate? – Compliance with (COSHH) regulations?
3. Health surveillance
What happens when a supermarket opens?
X X Xsurveillance no surveillance
UK Supermarket bakeries
Increased incidence of
occupational asthma No cases of
occupational asthma
Occupational Dermatitis
Endogenous (constitutional) Exogenous (contact)
– Irritant (acute/chronic)– Allergic (immediate/delayed)
Occupational Dermatitis
Allergic Latency Lag period Eye lid swelling Papules and vesicles Exposure to a known
sensitiser
Irritant usually involves the
hands Scaling and redness Papules and vesicles
are unusual Exposure to a known
irritant
Causes of Occupational Dermatitis
Irritant “Wet work” Soap detergents vegetable juices/fruit fish/meat dough
Allergic Latex Biocides/preservatives
(e.g. formaldehyde) Chrome salts Plant allergens (e.g. onion,
garlic, spices) Epoxy resin monomers Hairdressing chemicals
History
Duration Site Work history Exposure to known allergens/irritants Improvement away from work Treatment
Management
Avoid exposureAllergen/irritant replacement Skin protection Change job Drug treatment
Occupational Cancer
Target Organ Lung
Nasal sinuses Urothelial tract
Liver(angiosarcoma)
Carcinogen Asbestos, As, Be, Cd,
Cr(VI), Ni, Fe, BCME Ni Rubber, Dyes, Al,
Tar/pitch VCM
Industrial Injuries Disablement Benefit
Prescribed diseases (IIAC)relevant diseaserelevant occupationAdministered by DWP
Case 3: Assessing fitness for workY You are an occupational physician. A 29-year old HIV positive doctor has been offered a post on an anaesthesia
rotation. 1. Is it relevant to know how HIV was acquired? 2. How will you assess whether s/he is medically fit for the job? 3. What information will you need, to make a fully informed assessment?
Fitness for work
JobRelevant medical historyRisks (self, colleagues,
employer, public)
A Model Framework for Assessment of Medical Fitness for Work
Person•Relevant medical history
•Functional capacity (physical/psychological)
Job•Demands/requirements
•Safety critical work•Hours, travel etc
Risks•Employee•Employer
•Colleagues•3rd parties
(customers/service users/public)
Fitness for Work
Aims & Objectives
Aim:To be able to apply the basic principles of occupational medicine to your
professional practice as doctors
Objectives:1. Know what questions to ask in order to take an appropriate and relevant
occupational history2. Identify factors or patterns in a patient’s history that may indicate a work related
contribution to ill health3. Consider a work related health dilemma and reach a conclusion with reasons4. List 3 causative agents and related work activities for occupational asthma,
allergic contact dermatitis and cancer.5. Specify what information is necessary to make a fully informed assessment of
an individual’s medical fitness for work