Inner ear decompression sickness

Inner Ear Decompression Sickness (IEDCS) is a medical condition affecting the inner ear that arises from a rapid decrease in pressure, such as when a diver ascends too quickly from a deep dive. It is a type of decompression sickness (DCS), which is also known as "the bends." IEDCS specifically affects the vestibular and auditory functions of the ear, leading to symptoms such as vertigo, hearing loss, and tinnitus.

Causes

IEDCS occurs when inert gases, primarily nitrogen, which are dissolved in body tissues and fluids under high pressure, form bubbles inside the body as the pressure decreases. The inner ear is particularly susceptible to these changes due to its complex fluid-filled chambers. Rapid ascent without adequate decompression stops increases the risk of bubble formation in the blood or tissues, which can then interfere with the normal function of the inner ear.

Symptoms

The symptoms of IEDCS can vary but often include:

• Vertigo: A sensation of spinning or dizziness that can be severe and disorienting.
• Hearing loss: Partial or complete loss of hearing in one or both ears.
• Tinnitus: Ringing or buzzing noises in the ears.
• Nausea and vomiting.

These symptoms can develop quickly after surfacing and require immediate medical attention.

Diagnosis

Diagnosis of IEDCS involves a medical history review, focusing on recent diving activities, and a physical examination. Audiometric tests may be conducted to assess hearing loss, while vestibular function tests can help determine the extent of balance disturbance. Imaging studies, such as MRI, are sometimes used to rule out other conditions.

Treatment

The primary treatment for IEDCS is Hyperbaric oxygen therapy (HBOT). This involves placing the patient in a hyperbaric chamber and administering 100% oxygen at pressures higher than atmospheric pressure. The increased pressure and oxygen concentration help reduce the size of the nitrogen bubbles and promote their dissolution back into the body tissues and fluids, restoring normal function to the affected areas of the inner ear.

Prevention

Prevention of IEDCS focuses on adhering to safe diving practices, including:

• Following recommended ascent rates and decompression stops as outlined in diving tables and dive computers.
• Avoiding rapid ascents.
• Staying well-hydrated.
• Avoiding diving when unfit or unwell.
• Using enriched air nitrox to reduce nitrogen absorption for certain dives.

See Also

• Decompression sickness
• Hyperbaric medicine
• Scuba diving safety