Decompression sickness or Decompression illness

Decompression sickness is the pathology caused by the formation of bubbles in the body from inert gases dissolved in tissues, which occurs as a result of a reduction in ambient pressure.

Inert gases are those that are not metabolized or involved in any biological process. The inert gas in air is nitrogen. Noble gases, such as helium, which is used in some deep diving gas mixtures, are also inert gases.

Enfermedad descompresiva o enfermedad por descompresiónDuring the compression phase, there is an increase in the partial pressure of inert gases, which dissolve and are absorbed by various tissues to a greater or lesser extent depending on various factors such as exposure time, solubility coefficient, temperature, or blood flow.

When the diver begins ascent (decompression phase), the opposite phenomenon occurs: inert gases are gradually released from tissues and enter the bloodstream and lungs, from where they are eliminated. If decompression occurs too quickly, the inert gas present in the tissues may converge to form bubbles, which can injure tissues due to direct pressure (Type I decompression sickness) or enter the circulation (gas embolism), leading to damage in distant territories, mainly the nervous system (Type II decompression sickness).

The inner ear is particularly sensitive to microbubbles due to its low tolerance to hypoxia, so it can sometimes be affected in isolation without other manifestations of decompression sickness. Additionally, some factors may predispose to its appearance, such as diver inexperience, successive dives, poor physical condition, or ascent to altitude by flight or mountaineering within 24 hours of the last dive. However, decompression sickness of the inner ear can occur even without these circumstances. In these cases, it is often associated with the persistence of a patent foramen ovale.

Symptoms of decompression sickness

Symptoms of decompression sickness of the inner ear include dizziness with rotational sensation, sometimes accompanied by nausea and vomiting, hearing loss, and tinnitus. Therefore, the presentation may closely resemble that of inner ear barotrauma; however, unlike barotrauma, there is usually no difficulty equalizing during the dive, nor are there accompanying symptoms of middle ear barotrauma. Symptoms typically have a later onset, mostly after the dive has ended or during ascent, and vestibular symptoms (vertigo) tend to predominate over cochlear or auditory symptoms.

Treatment of Decompression Sickness

The treatment in these cases is the same as for any other manifestation of decompression sickness and is based on hyperbaric oxygen therapy. However, it is important to differentiate between decompression sickness and inner ear barotrauma, as recompression in a hype

Paciente en tratamiento en cámara hiperbárica


rbaric chamber in the latter case would be detrimental. If there is doubt, this treatment could be performed after the placement of transtympanic drainage tubes. Despite treatment, sequelae often remain, such as irreversible hearing loss or residual instability. Therefore, as with most diving-related pathologies, prevention is key.

At Altiorem Clinic, we specialize in underwater medicine. If you have any questions or would like to schedule an appointment for a check-up, do not hesitate to contact us.