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What is Decompression Illness?

Decompression illness (DCI) is an all-inclusive phrase that describes two similar diseases, decompression sickness (DCS) and arterial gas embolism (AGE).

In scuba diving, we use the generalised term of DCI when referring to the manifestations and management of both disorders (e.g. decompression illness vs. sickness).

Who Can Get Decompression Illness (DCI)?

Put simply, decompression injury DCI is caused by the presence of gas bubbles in the body.

So, who gets DCI most often? In fact, besides scuba divers, it can also affect:

Here's the reason why! A sudden reduction in the surrounding pressure (ambient) is the predominant risk factor for getting decompression illness. But, other circumstances often intensify the likelihood of suffering DCI while scuba diving.

Despite following a similar risk profile, some scuba divers get DCI more often than others. Hence, we need to learn more about these individual risk factors. Remember, almost any dive profile can produce some typical symptoms of decompression illness.

Here's the thing:

Bubbles can enter the bloodstream if a pressure build-up in the lungs forces air from the lungs into the blood. Plus, making a rapid ascent contributes significantly to the risk of suffering arterial gas embolism (AGE).

AGE can result from breath hold diving or from inadequate exhalation on ascent. Trapping of air in the lungs, due to the asthma respiratory disorder, mucus, water inhalation, laryngospasm, cough, or cold can also be the cause of gas embolisms.

On the other hand, bubbles in the bloodstream and body tissues can result from excess nitrogen (or another inert gas) from inadequate decompression after a dive.

This divers' disease is known as decompression sickness (DCS) - often called 'the bends diving hazard' and caisson disease.

DCI Risk Factors

DCI can, and does, occur on dives that are well within the no stop limits of dive tables and dive computers because they cannot accurately predict the formation and distribution of bubbles in the body.

Bubbles in the blood and body tissues can block or damage blood vessels. This usually reduces the blood supply to various parts of the body.

They can also interfere with nerve function and cause undesirable chemical changes in the blood. Doing so further reduces effective circulation.

The following predisposing risk factors are known to increase the likelihood of scuba divers getting decompression illness:

Important: If symptoms to those of decompression illness are present after diving, never exclude DCI because of what may appear to be a safe dive according to the dive computer or tables.

Decompression Illness Symptoms

Although these usually occur within fifteen (15) minutes of diving, they may also develop up to twelve (12) hours after the dive. It can be even later if there is exposure to altitude.

Symptoms of DCI sometimes disappear spontaneously, particularly if the diver is breathing oxygen. But, medical consultation, evaluation, and treatment in a recompression chamber are usually required to minimise the tissue damage and to avoid a recurrence of the symptoms.

Decompression Sickness Symptoms

Signs and Symptoms of Severe Decompression Illness

Decompression Illness Treatment

The best treatment for decompression illness (DCI) and arterial gas embolism (AGE) is recompression. A diver with DCI symptoms will need treatment at a medical facility before undergoing recompression in a hyperbaric chamber.

Special Considerations for Decompression Illness

Intravenous (IV) fluids are preferable. Oral fluids are given only if the diver is conscious, stable and is not suffering from stomach pain, nausea or vomiting and is able to urinate. Record the amount and type of fluid given, urinary output, and check for bladder distension.

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