Occupational decompression sickness

Decompression sickness (also known as the bends or caisson disease) occurs when there is a rapid decrease in pressure while diving rapidly after diving, exiting a diving bell or high-pressure chamber, or ascending to high altitudes, … causing gases dissolved in the blood or tissues to form bubbles in the blood vessels.

Henry’s law states that the amount of gas dissolved in a liquid is proportional to the partial pressure of the gas when in equilibrium with the liquid. Therefore, the amount of inert gas (e.g., nitrogen, helium, …) dissolved in blood and tissues increases at higher pressures.

1. What is occupational decompression sickness?

Occupational decompression sickness (DCS, also called diver’s disease or Caisson disease) occurs due to sudden changes in environmental pressure at work, forming gas bubbles in the blood vessels or tissues due to abrupt external pressure changes during labor.

There are 2 types of decompression sickness:

• Type I: Involves joints, skin, and lymphatic system; milder and usually not life-threatening.
• Type II: Involves serious neurological or cardiovascular issues; sometimes life-threatening and affects multiple organ systems.

The spinal cord is particularly vulnerable; other susceptible organs include the brain, respiratory system (e.g., pulmonary embolism), and circulatory system (e.g., heart failure, cardiac shock).

Discover Occupational Decompression Sickness Risk Calculator. This tool provides detailed risk assessments and safety prevention recommendations, helping divers and managers better understand risks in their work. With a multidimensional database and advanced algorithms, the tool is a reliable source for both divers and occupational safety experts. Its main goal is to protect divers’ health and minimize decompression sickness risks while promoting safety and sustainability in professional diving.

2. Occupations at risk of decompression sickness

Occupations at risk for occupational decompression sickness typically include:

• Divers.
• Working in high-pressure chambers, caissons, deep mines, or underground works.
• Other jobs involving sudden external pressure changes during work.

3. Mechanism and causes of occupational decompression sickness

During ascent, as surrounding pressure decreases, gas bubbles (mainly nitrogen) may form. Bubbles can appear in any tissue, causing local symptoms, or travel through the bloodstream to distant organs (arterial gas embolism).

4. Symptoms and effects of occupational decompression sickness

Severe symptoms may appear within minutes of surfacing, but in most patients, they develop gradually. Symptoms include:

• Type I: Usually causes gradually increasing joint pain (commonly elbows and shoulders) and muscle pain; worsens with movement and is described as “deep” and “aching.” Other signs include lymphatic swelling, mottled skin, itching, and rash.
• Type II: Neurological symptoms and sometimes respiratory symptoms. Typical signs are mild paralysis, tingling, numbness, difficulty urinating, and loss of bowel or bladder control. Headache and fatigue may occur but are nonspecific. Dizziness, tinnitus, and hearing loss may occur if the inner ear is affected. Severe symptoms include seizures, slurred speech, vision loss, confusion, and coma. Death can occur.
• Respiratory distress is a rare but severe symptom; includes difficulty breathing, chest pain, and pulmonary edema. Large gas embolisms may cause rapid circulatory failure and death.
• Avascular necrosis is a late manifestation, often occurring without prior symptoms. It results from prolonged or repeated high-pressure exposure (commonly in compressed-air workers and commercial divers, not recreational divers). Destruction of shoulder and hip joint surfaces can cause chronic pain and disability from secondary osteoarthritis.

5. Protective equipment to prevent decompression sickness

Depending on the profession, workers wear appropriate protective equipment. For divers, necessary protective gear includes:

• Breathing apparatus and compressed air tanks, the most essential equipment, provide oxygen for breathing underwater.
• Diving mask to see underwater and breathe via the snorkel or regulator.
• Diving suit to maintain body temperature and protect against the underwater environment.
• Safety line to keep divers close to the boat and ensure safety during dives.
• Diving lights for underwater visibility.

6. Compensation for workers with decompression sickness

In Vietnam, workers with occupational decompression sickness are compensated according to Social Insurance Law. Benefits include:

• Compensation for health loss according to legal regulations, based on severity and work capacity.
• Healthcare and treatment to minimize symptoms.
• Other benefits such as health insurance, social insurance, family allowances, and leave entitlements.

Workers must meet legal requirements and submit proper documentation to receive compensation. Contact social insurance agencies for guidance on registration and claims.

7. Treatment of decompression sickness

Treatment is based on dissolving gas bubbles and releasing excess gas through the lungs by quickly returning the patient to a high-pressure environment. Medications cannot dissolve large gas bubbles.

Severe cases can be treated with hyperbaric oxygen therapy, combined with medications and physical therapy to restore organ function.

For acute cases, provide first aid: remove diving gear, lay patient supine, maintain blood pressure and cerebral perfusion, and transport to a hospital or hyperbaric center immediately. Use saline solutions only; avoid protein or nutrition solutions. Rapid first aid and transport can enable full recovery.

8. Prevention of occupational decompression sickness

Workers should:

• Strictly follow diving procedures.
• Regularly train and test divers.
• Use specialized diving equipment suitable for the job.
• Monitor divers’ health before and during work. Conduct regular medical checks according to legal requirements.

9. Employer responsibilities in preventing decompression sickness

Employers must protect workers’ health and safety:

• Ensure a safe working environment.
• Provide PPE, training, and guidance on using equipment and preventing decompression sickness.
• Conduct regular health checks to detect and treat decompression sickness early.
• Support treatment and compensation according to law.
• Perform workplace environment monitoring and report results periodically to improve working conditions.

10. National Occupational Environment Monitoring Center

Nam Viet Occupational Environment Monitoring Center is a professional unit monitoring and measuring workplace environmental quality across all provinces in Vietnam. With an experienced team of monitoring specialists, the center uses modern equipment to ensure accuracy and reliability.

REGISTER FOR WORKPLACE ENVIRONMENT MONITORING SERVICE

The center also assists clients in planning, handling, and tracking workplace environmental issues, prioritizing customer satisfaction and providing optimal solutions.

With investments in technology and skilled staff, Nam Viet’s monitoring center is a reputable unit in Ho Chi Minh City, focusing on:

• Maintaining brand reputation and high service quality.
• Providing the best and most suitable solutions for clients.
• Team of Masters and Engineers with expertise, committed to environmental protection and business benefits.

• Clients will receive professional service from monitoring experts and the best cost advantages.

11. Workplace Environment Monitoring Price List

To help businesses perform professional workplace environment monitoring, Nam Viet provides a price list for monitoring services with quality and reasonable cost.

• Our price list provides detailed information on the cost of monitoring services, including travel, measurements, analysis, and reporting. Clients can trust the accuracy and reliability of our reports.
• We commit to offering competitive and reasonable prices and provide prompt professional consultation for any questions.
• Clients can easily choose service packages that suit their needs. We ensure maximum satisfaction with professional service quality.