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Decompression sickness is an occupational pathology that primarily affects divers and divers. In medical dictionaries, this disorder is called decompression sickness (DCS).
Caisson disease – what is it?
Decompression sickness is a violation of the normal blood supply to organs and tissues, provoked by a sharp drop in the pressure of gases that a person inhales (oxygen, nitrogen, hydrogen). Gases that are present in the blood in a dissolved form are converted into bubbles. They interfere with normal blood flow, contribute to the destruction of the vascular wall and tissue cells. If the disease has a severe course, then the person may remain disabled or even die. Often this condition develops in people who are in conditions of high atmospheric pressure. It manifests itself during the period when a person returns to an environment with normal atmospheric pressure, but at the same time does not comply with the necessary safety measures.
At risk are people who are engaged in the construction of ports, bridges, underwater tunnels, that is, all divers. Moreover, not only professionals, but also lovers of deep diving can suffer. A person in a special chamber-caisson or in a wetsuit is exposed to increased atmospheric pressure. It increases specifically to balance the water pressure on the suit or camera.
Diving under water takes place in 3 stages:
The stage of compression during which the pressure is increased.
The stage of performing the necessary work, when a person is in conditions of high atmospheric pressure.
The stage of decompression, when the pressure is reduced, and the person rises to the surface.
If during the first or third stage violations were made, then the diver may develop decompression sickness.
People learned about the disease in 1841, when the first caisson chambers with air pumps were invented. They were used for the construction of bridges and tunnels passing under water. People who stayed in these cells complained of pain in the joints, numbness of the arms and legs, and paralysis. Now all these symptoms have been carefully studied, they are classified as signs that characterize the decompression sickness of the first type.
Variants of the course of decompression sickness
Modern medicine distinguishes 3 types of decompression sickness.
They differ depending on which organs were damaged during diving:
The first type of decompression sickness. This type of disease is life-threatening, but it is not great. A person will experience joint pain, his lymphatic system, skin and muscles will suffer. In addition to pain in the shoulder and elbow joints, the victim will have increased pain in the back and muscles. They will gain intensity when you try to make a move. The nature of the pain is boring. Skin rashes are also observed in the form of spots, which are very itchy, lymph nodes increase in size.
The second type of decompression sickness poses a threat to human life. The pathological process will involve the brain and spinal cord, circulatory and respiratory systems. A person experiences urination disorders, he has severe headaches, tinnitus. If the disease has a severe course, then the victim may become deaf and blind, coma is not excluded. Choking is also a symptom of type XNUMX bend sickness, but it rarely happens. However, shortness of breath and chest pain should not be left unattended, as this is fatal. Another danger of a long stay of a person in conditions of high atmospheric pressure is the development of aseptic necrosis of bone tissue.
After a decompression event, decompression sickness develops in half of the people. Most often, the disease has a severe course. The first signs of a violation in the body appear 6 hours after rising to the surface. Although there is evidence of the development of decompression sickness even 24 hours after the dive.
developmental pathogenesis
To find an explanation for how decompression sickness develops, it is necessary to turn to physics, namely Henry’s law. It says that gases dissolve in a liquid with such intensity with which the liquid itself exerts pressure on these gases. That is, the higher the pressure, the better the gases dissolve. The faster the pressure drops, the faster the gases in the blood will form bubbles. Moreover, they will appear not only in the blood, but also in other fluids of the human body. Therefore, with decompression sickness, the spinal cord and brain, joints and lymphatic system suffer.
The gas bubbles that appeared during a sharp pressure drop will unite and block the vessels, as well as destroy the cells, or pinch them. The result of such a violation is blood clots, which can either rupture the vessel or cause the death of its tissues. With the flow of blood, gases travel throughout the body and can cause malfunction in almost any organ.
So, the reasons that can lead to decompression sickness:
Too fast rise to the surface from depth.
Immersion in cold water.
Extreme fatigue or being under stress.
Overweight.
The age of the person.
Air travel after deep diving.
The following reasons will lead to the development of pathology when diving in a caisson chamber:
Too long a person stays under water.
Dive to a depth of more than 40 meters. Under such conditions, the pressure rises by 4 atmospheres or more.
How to detect and treat decompression sickness?
In order for the doctor to be able to make a correct diagnosis, he needs to report in as much detail as possible about the symptoms that a person experiences. The doctor will prescribe an MRI or CT scan of the brain and spinal cord to the patient, which will establish characteristic disorders in them. Dysbaric osteonecrosis is also a sign of decompression sickness, which can be detected through tomography.
In 80% of cases, the disease can be completely cured. However, for this, therapy should be prescribed as early as possible.
For recompression, special equipment is used that supplies oxygen in large quantities to the victim’s bloodstream. This allows you to remove excess nitrogen bubbles from the blood. Oxygen enters the human body under high pressure. If it is not possible to carry out therapy immediately after rising from a depth, then the patient should be taken to a medical facility as soon as possible.
Subsequent therapy will be aimed at eliminating the symptoms of decompression sickness. The patient is prescribed painkillers, drugs to relieve inflammation and to strengthen the immune system.
So that a person does not develop decompression sickness, you need to correctly calculate the decompression regime, slowly rise from the depth. This allows the body to adapt and not react sharply to pressure drops. Modern cameras are equipped with computer technologies that minimize the risks of decompression sickness. However, the computer is not able to assess the individual characteristics of the body of each person. In addition, it happens that people themselves simply ignore all the rules for safe diving and ascent to the surface.
It is worth taking into account that decompression sickness can develop not only in divers who dive very deep. In a mild degree, pathology can occur even in divers. Therefore, it is so important to know the symptoms of the disease and avoid the causes that lead to its occurrence.
Video: what is decompression sickness?