Arterial gas embolism involves obstruction of the blood supply to the organs which is caused by the presence of bubbles in an artery. The air bubbles can access the arterial or the venous blood after decompression sickness or pulmonary barotrauma.
Once the bubbles are present in the arteries, they can travel to any organ and block the small blood vessels, usually in the brain but also in the heart, kidneys and skin. A large-sized air embolism can obstruct the stream in the heart chambers or the large-sized arteries. Remember that arterial gas embolism is the main cause of fatality among divers.
What are the symptoms?
The indications of arterial gas embolism typically manifest within a few minutes of reaching the surface. If arterial gas embolism affects the brain, it often resembles a stroke which results to partial paralysis, confusion or loss of sensation. Some cases involve sudden loss of consciousness or seizures. In severe cases of arterial gas embolism, it can result to shock and death.
The other symptoms might stem from an underlying pulmonary barotrauma or decompression sickness or from arterial gas embolism in any of the following:
- Skin (pale tongue, purplish-bluish skin blotches)
- Heart (abnormal heart rhythms, heart attack, cardiac arrest)
- Kidneys (acute kidney injury, protein or blood in the urine)
How is it diagnosed
Divers who lose consciousness during ascent or right after are assumed to have arterial gas embolism. Immediate treatment is vital. In some cases, imaging tests are carried out but not always reliable.
An individual should lie down and oxygen is given. It is vital to return him/her as soon as possible to an environment with high pressure so that the air bubbles are compressed and forced to dissolve in the blood. Many healthcare facilities have high-pressure or hyperbaric chambers for this purpose.
Flying even at low altitudes reduces the atmospheric pressure and enables the bubbles to further expand, but it can be justified if it saves enough time in moving an individual to a suitable chamber. If possible, an individual should fly in a plane that is pressurized to sea level or should not fly higher than 2,000 feet.