FAQs

Decompression Illness includes both DCS and CAGE. Both refer to different concepts related to diving safety and physiology. Here’s a breakdown of each term:

DCS (Decompression Sickness)

• Definition:
  Decompression Sickness (DCS), also known as “the bends,” is a condition that occurs when dissolved gases (primarily nitrogen) form bubbles in the bloodstream and tissues due to a rapid decrease in pressure during ascent.
• Causes:
  • Ascending too quickly after a dive.
  • Failure to perform necessary decompression stops or exceeding no-decompression limits.
  • PLEASE ALSO BE AWRE THAT DCS CAN HAPPEN WHILE DIVING WITHIN NDL LIMITS.
• Symptoms:
  • Joint and muscle pain
  • Fatigue
  • Dizziness
  • Skin rashes
  • Neurological symptoms (e.g., numbness, confusion) in severe cases
• Treatment:
  • Immediate administration of 100% oxygen
  • Recompression therapy in a hyperbaric chamber

CAGE (Cerebral Arterial Gas Embolism)

• Definition:
  Cerebral Arterial Gas Embolism (CAGE) occurs when air bubbles enter the bloodstream and block arteries, particularly those supplying the brain. This usually results from lung over-expansion injuries (pulmonary barotrauma) during a rapid or improper ascent.
• Causes:
  • Holding your breath during ascent (violating the basic diving rule to breathe continuously).
  • Rapid ascent causing expanding air to rupture lung tissue and release air into the bloodstream.
• Symptoms:
  • Sudden loss of consciousness
  • Seizures
  • Confusion or disorientation
  • Visual disturbances
  • Paralysis or weakness in limbs
• Treatment:
  • Immediate administration of 100% oxygen
  • Recompression therapy in a hyperbaric chamber

Summary

• DCS is primarily caused by nitrogen bubbles forming during a rapid ascent.
• CAGE is caused by expanding air trapped in the lungs entering the bloodstream, often due to holding your breath during ascent.

Both conditions are serious medical emergencies and require immediate treatment with oxygen and hyperbaric therapy. Proper ascent techniques and adherence to dive safety guidelines can help prevent both.

Hyperbaric medicine is the primary and most effective treatment for Decompression Sickness (DCS). It involves the use of a hyperbaric chamber where a patient breathes 100% oxygen while exposed to increased atmospheric pressure. This helps resolve the nitrogen bubbles that cause DCS. Here’s how hyperbaric medicine helps:

1. Increases Ambient Pressure

• In a hyperbaric chamber, the pressure is increased to levels higher than sea level (often between 2.5 and 3.0 ATA or more).
• This elevated pressure helps shrink nitrogen bubbles trapped in the bloodstream and tissues, relieving symptoms caused by the bubbles obstructing blood flow.

2. Facilitates Bubble Reabsorption

• The increased pressure reduces the size of the nitrogen bubbles (following Boyle’s Law, which states gas volume decreases under pressure).
• The smaller bubbles are more easily dissolved back into the bloodstream and safely eliminated through the lungs.

3. Enhances Oxygen Delivery

• The patient breathes 100% oxygen (as opposed to the 21% oxygen in regular air).
• At higher pressures, oxygen is dissolved directly into the plasma (the liquid part of the blood) in significantly higher amounts.
• This helps deliver oxygen to tissues that were deprived of blood flow due to nitrogen bubbles, promoting healing.

4. Reduces Inflammation

• Hyperbaric oxygen therapy reduces inflammation and swelling caused by DCS.
• This helps tissues recover faster from any damage caused by the bubbles or lack of oxygen.

5. Improves Tissue Repair

• By delivering high concentrations of oxygen, hyperbaric medicine helps repair damaged tissues and promotes cell growth.
• This is particularly important if DCS has caused damage to joints, muscles, or the nervous system.

Typical Hyperbaric Treatment Protocols

• Recompression Therapy typically follows the U.S. Navy Treatment Tables (such as Table 6).
• Treatment involves stages of pressurization (e.g., to 60 feet or 18 meters) and gradual decompression while breathing pure oxygen.
• A session can last 2 to 5 hours, and multiple sessions may be needed depending on the severity of DCS.

Summary of Benefits

1. Reduces bubble size through increased pressure.
2. Facilitates nitrogen elimination by allowing bubbles to dissolve safely.
3. Increases oxygen supply to tissues, counteracting hypoxia.
4. Reduces inflammation and swelling.
5. Promotes healing of damaged tissues.

By combining these effects, hyperbaric medicine effectively reverses the dangerous symptoms of DCS and reduces the risk of long-term damage.

Scuba diving is generally safe when practiced correctly, but divers often experience certain complaints or issues. These range from mild discomfort to potentially serious medical conditions. Here are the most common diving complaints:

1. Barotrauma

Caused by pressure differences between air spaces in the body and the surrounding water. Types include:

• Ear Barotrauma (Middle Ear Squeeze)
  • Cause: Failure to equalize pressure during descent.
  • Symptoms: Ear pain, fullness, hearing loss, or bleeding.
• Sinus Barotrauma
  • Cause: Inability to equalize pressure in sinus cavities due to congestion.
  • Symptoms: Pain, nosebleeds, or pressure headaches.
• Pulmonary Barotrauma
  • Cause: Holding your breath during ascent (violating the “never hold your breath” rule).
  • Symptoms: Chest pain, shortness of breath, and potentially Arterial Gas Embolism (AGE).

2. Decompression Sickness (DCS) / “The Bends”

• Cause: Rapid ascent or missed decompression stops leading to nitrogen bubbles forming in the bloodstream.
• Symptoms: Joint pain, muscle aches, fatigue, dizziness, and neurological issues.
• Prevention: Proper ascent rates, adhering to dive tables/computers, and safety stops.

3. Hypothermia

• Cause: Extended exposure to cold water (even in warm countries).
• Symptoms: Shivering, numbness, confusion, and fatigue.
• Prevention: Wearing appropriate thermal protection (wetsuits or drysuits).

4. Mask Squeeze

• Cause: Failure to equalize pressure in the mask during descent.
• Symptoms: Facial bruising, red eyes, and discomfort.
• Prevention: Exhale through your nose to equalize pressure in the mask.

5. Seasickness / Motion Sickness

• Cause: Movement of boats or currents.
• Symptoms: Nausea, dizziness, and vomiting.
• Prevention: Motion sickness medication, staying hydrated, and focusing on the horizon.

6. Fatigue

• Cause: Dehydration, physical exertion, and thermal stress.
• Symptoms: Tiredness and weakness after a dive.
• Prevention: Proper hydration, rest, and appropriate gear.

7. Sunburn

• Cause: Prolonged exposure to sun while on a dive boat or during surface intervals.
• Prevention: Using waterproof sunscreen and wearing protective clothing.

8. Cuts, Scrapes, and Marine Life Injuries

• Cause: Contact with coral, rocks, or stings from jellyfish and other marine life.
• Prevention: Good buoyancy control, wearing exposure suits, and avoiding contact with marine life.

9. Panic and Anxiety

• Cause: Fear, equipment malfunctions, or unexpected situations underwater.
• Symptoms: Rapid breathing, confusion, and loss of control.
• Prevention: Proper training, dive planning, and relaxation techniques.

10. Dehydration

• Cause: Breathing dry compressed air, sweating, or vomiting.
• Symptoms: Dry mouth, fatigue, dizziness, and increased risk of DCS.
• Prevention: Drinking plenty of fluids before and after diving.

Summary

Most diving complaints can be minimized or avoided by following safe diving practices, maintaining good physical health, and using proper equipment. Knowing how to recognize and respond to these issues helps ensure a safe and enjoyable diving experience.