10.14 Entrapped Gasses

10.14.2 Define barotrauma.

Barotrauma is injury or pain caused by a difference in pressure between a gas-filled space in the body and the surrounding atmosphere.

10.14.4 Explain the causes of barotrauma.

Barotrauma occurs when trapped gas within the body expands or contracts as the surrounding atmospheric pressure changes.

With an increase in altitude and corresponding decrease in atmospheric pressure, trapped gas tends to expand.

During a descent, atmospheric pressure increases and trapped gas tends to contract.

If the pressure cannot equalise, a pressure difference develops which may cause pain or injury.

Gas may become trapped in the:

• middle ear;
• sinuses;
• stomach and intestines; and
• teeth.

The lungs also contain gas but normally equalise pressure through normal breathing.

Conditions such as:

• colds;
• sinusitis;
• ear infections;
• hay fever; and
• allergies

may block the normal passages used to equalise pressure and increase the risk of barotrauma.

Key point

Climb — trapped gas expands.

Descent — trapped gas contracts.

10.14.6 Describe the symptoms of barotrauma.

Symptoms of barotrauma may include:

• ear pain or discomfort;
• sinus or facial pain;
• tooth pain;
• abdominal discomfort;
• dizziness;
• vertigo; and
• difficulty hearing.