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Code for the Medical Examination of Divers

Disclaimer: This resource has been prepared to help the workplace parties understand some of their obligations under the Occupational Health and Safety Act (OHSA) and regulations. It is not legal advice. It is not intended to replace the OHSA or the regulations. For further information please see full disclaimer.

Note: This code is referenced in Ontario Regulation 629/94 (Diving Operations) made under the Occupational Health and Safety Act.

1. Physician knowledge and competency

This examination shall be conducted by a physician with basic training in diving medicine who is capable of screening workers for exposure to atmospheric pressure. The physician shall:

  1. (1) Be licensed to practice in Ontario;
  2. (2) Have completed a basic training course in diving medicine;
  3. (3) Have an effective current working knowledge of the physical laws affecting the diver and the underwater operation through continuing medical education;
  4. (4) Have an understanding of the interaction that occurs between these physical laws and the diver’s physiology and of the implications of this interaction for the diver;
  5. (5) Have sufficient awareness of the pathological conditions that can arise as a consequence of exposure to pressure; and
  6. (6) Have the ability to perform a competent physical evaluation of diving candidates, divers and caisson workers.

2. Purpose

The objective of the medical examination is to protect the health of divers by:

  1. (1) identifying pre-existing health conditions that could be aggravated by exposure to changes in atmospheric pressure (compression and decompression);
  2. (2) evaluating the effect of changes in atmospheric pressure on divers;
  3. (3) enabling remedial action to be taken when necessary to ensure the safety of the diver; and
  4. (4) providing health education on the effects of changes in atmospheric pressure and on the results of the medical examination.

3. Medical examination

  1. (1) Medical and occupational history;
  2. (2) Physical examination;
  3. (3) Clinical tests;
  4. (4) Determination of fitness; and
  5. (5) Health education.

4. Medical screening and occupational history

At the medical examination the examining physician shall review the diver's personal log. A screening questionnaire[1] shall be administered at the examination to identify any symptoms or medical conditions that could impact fitness to dive.

An occupational history shall be undertaken to identify:

  1. (a) previous exposure to changes in atmospheric pressures (both occupational and non-occupational);
  2. (b) history of frequency and duration of exposure to changes in atmospheric pressure since previous examination;
  3. (c) history of signs and symptoms that may indicate prior injury as a result of compression or decompression injury such as middle ear trauma, air embolism, decompression sickness, oxygen convulsions, vestibular damage, high pressure neurological syndrome and aseptic bone necrosis.

5. Physical examination

During the physical examination, particular attention shall be directed to those systems that may be affected by changes in atmospheric pressure and stress involved in diving, for example, cardiopulmonary, ear, nose and throat (ENT), musculoskeletal system and central nervous system.

6. Clinical tests

Clinical tests aid in the assessment of a diver's fitness for and continued exposure to changes in atmospheric pressure and the stress involved in diving. Test requisition forms must indicate that the patient is a diver and that the purpose of the investigation is to assess medical fitness to dive. This will enable the interpreting physician (e.g., radiologist, internist/cardiologist, or respirologist) to report the test results appropriately.

  1. (1) Blood work
    A complete blood count shall be conducted on the initial examination and with each subsequent diving medical. Other blood work (e.g., sickle cell test) shall be conducted if clinically indicated.
  2. (2) Urinalysis
    Blood, glucose and protein urinalysis shall be conducted on the initial examination and with each subsequent diving medical. Other urinalysis testing shall be conducted if clinically indicated.
  3. (3) Pulmonary function tests
    Pulmonary function tests shall be undertaken at the initial examination and periodically if clinically indicated. They shall include FVC, FEV1, FEV1/FVC ratio, FEF 25-75% or other equivalent flow rate measurement that could indicate small airways dysfunction or air trapping. Particular attention must be given to indices of flow at low-mid volumes. Values less than 75% of predicted are not necessarily disqualifying but must trigger detailed pulmonary function tests and respirology consultation, perhaps with methacholine challenge testing.
  4. (4) Chest X-rays
    Chest X-rays shall include full-size posteroanterior (PA) (inspiratory and expiratory) and lateral. They shall be conducted on the initial examination and periodically if clinically indicated.
  5. (5) Electrocardiogram (with exercise tolerance tests)
    An electrocardiogram (ECG) shall be conducted in accordance with the diver’s age, as follows:
    1. (a) Less than 40 years of age – initial 12 lead resting ECG;
    2. (b) At 40 years of age – standardized exercise ECG;
    3. (c) Over 40 years of age – resting ECG required every two years to age 50; and
    4. (d) At or over 50 years of age – standardized exercise ECG required annually.
    An ECG shall also be conducted as clinically indicated.
  6. (6) Pure tone audiogram
    A pure tone audiogram shall be performed on both ears, 250-8000 Hz inclusive, at least 12 hours after any high noise exposure. This audiogram shall be conducted at the time of initial examination and then periodically every two years. Additional audiograms must be conducted if clinically indicated (e.g., after barotrauma).

7. Determination of fitness

When making a determination of ‘fit to dive’, ‘fit to dive with limitations’, or ‘unfit to dive’, the examining physician shall consider, but is not limited to, the following aspects:

  1. Age
  2. Physical fitness
  3. Medication and underlying conditions
  4. Smoking
  5. Disability and functional loss
  6. Infection and impaired immunity
  7. Obesity
  8. Mental health
    • Contraindications to diving may include schizophrenia, bipolar affective disorder, recurrent depression, disorders asymptomatic due to treatment, agoraphobia and claustrophobia.
  9. Alcohol, drug or substance misuse
  10. Respiratory system including asthma
    • Contraindications to diving include active sarcoidosis, cystic fibrosis with pulmonary involvement and fibrotic lung disease.
  11. Cardiovascular system including ischemic heart disease, dysrhythmia, pacemaker, patent foramen ovale, valvular heart disease, blood pressure and peripheral circulation.
    • Contraindications to diving include symptomatic ischaemic heart disease, conventional coronary bypass surgery, dysrhythmia that might cause incapacity in water, atrial or ventricular septal defects, aortic or mitral stenosis, coarctation, varicose veins associated with circulatory impairment and conditions known to be associated with impaired organ perfusion.
  12. Central nervous system
    • Contraindications to diving include recurrent, unprovoked loss of consciousness of unknown aetiology or recurrent episodes of fainting, epilepsy (unless seizure-free for ten years without treatment or medication and with expert assessment), neurological diseases such as stroke, multiple sclerosis or Parkinson’s disease, severe motion sickness and severe migraine, particularly with complicated aura and excess daytime somnolence.
  13. Musculoskeletal system
  14. ENT
    • Contraindications to diving include middle ear barotrauma until any middle ear fluid is reabsorbed, all active infections of the ear canal and middle ear until resolved, previous stapedectomy, Meniere’s disease and other vertiginous conditions, laryngocele until corrected, any condition causing an incompetent larynx and the presence of a tracheostomy.
  15. Vision
  16. Dental health
  17. Endocrine system (including diabetes and thyroid disease)
    • Contraindications to diving include the use of cortisol replacement, the presence or development of diabetic complications and gross thyroid disease.
  18. Genitourinary system
  19. Gastrointestinal system
    • Contraindications to diving include inflammatory bowel disease, gall bladder pathology and pancreatitis.
  20. Skin
    • Contraindications to diving include any condition that may affect thermal control and severe exfoliative disorders.
  21. Haematology
    • Contraindications to diving include sickle cell anaemia, other sickle cell disorders including beta thalassaemia and thalassaemia major.

Temporary medical restriction

Some temporary medical conditions may be aggravated by exposure to pressure. If they are present, exposure to pressure must be temporarily restricted until the disease or condition has been resolved. This may include conditions such as the following:

  1. (a) Upper respiratory infections (including otitis media and sinusitis);
  2. (b) Lower respiratory infections;
  3. (c) Barotrauma;
  4. (d) Decompression illness;
  5. (e) Wounds or physical injury (until healed or resolved);
  6. (f) Surgery (until healed and physical fitness restored);
  7. (g) Pregnancy;
  8. (h) Minor episodes of head injury; or
  9. (i) Acute or chronic skin infection.

8. Fitness certificate

The fitness certificate provided to the diver shall state:

  1. (a) that the diver is fit, fit with limitations or unfit to dive
  2. (b) that the medical examinations were conducted according to the Code for the Medical Examination of Divers, dated October 2013
  3. (c) the date of the examination
  4. (d) the date of the next required examination. Examinations are required:
    • i. Every two years if under age 40;
    • ii. Annually if age 40 or older; and
    • iii. More frequently if recommended by the person’s examining physician
  5. (e) the physician’s name, address and signature.

Not a required component of the code

At the discretion of the examining physician, other tests including psychometric testing and psychiatric examination may be undertaken.

Long bone imaging may be indicated in cases of suspected dysbaric osteonecrosis.

[1] CSA Standard Z275.2-11, "Occupational Safety Code for Diving Operations", Annex F, Occupational Diver’s Medical Fitness Examination may be used as the screening questionnaire.

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Disclaimer: This web resource has been prepared to assist the workplace parties in understanding some of their obligations under the Occupational Health and Safety Act (OHSA) and the regulations. It is not intended to replace the OHSA or the regulations and reference should always be made to the official version of the legislation.

It is the responsibility of the workplace parties to ensure compliance with the legislation. This web resource does not constitute legal advice. If you require assistance with respect to the interpretation of the legislation and its potential application in specific circumstances, please contact your legal counsel.

While this web resource will also be available to Ministry of Labour inspectors, they will apply and enforce the OHSA and its regulations based on the facts as they may find them in the workplace. This web resource does not affect their enforcement discretion in any way.