Decompression sickness - treatment of the disease. Caisson disease - an ailment of divers and amateur divers Caisson disease at what depth

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Decompression sickness history

This disease first appeared after the invention air pump and the subsequent invention in the city of caisson - a chamber with high blood pressure commonly used to build tunnels under rivers and anchor bridge piers in the ground. The workers entered the caisson through the airlock and worked in an atmosphere of compressed air, which prevented the chamber from flooding. After the pressure was reduced to the standard (1 atm), the workers often developed joint pains, and sometimes more serious problems - numbness, paralysis, etc., which sometimes led to death.

Physics and physiology of DCS

When inhaling, the air, entering the bronchi, reaches the alveoli - the smallest structural unit lungs. It is here that the very process of gas exchange between the blood and the external environment takes place, when the hemoglobin contained in the blood takes on the role of transporting oxygen molecules throughout our body. The nitrogen contained in the air is not assimilated in the body, but it always exists in it, in a dissolved - "quiet" - form, without causing any harm. Nitrogen begins to behave quite differently when it comes to scuba diving.

The amount of gas dissolved in a liquid directly depends on the gas pressure on the surface of this liquid. If this pressure exceeds the gas pressure in the liquid itself, then a gradient of gas diffusion into the liquid is created - the process of saturation of the liquid with gas begins. This process continues until the gas pressure in the liquid equals the gas pressure on the liquid surface. The saturation process takes place. With a decrease in external pressure, the opposite process occurs. The gas pressure in the liquid exceeds the external gas pressure on the liquid surface, the process of "desaturation" takes place. Gas begins to evolve from the liquid to the outside. The liquid is said to boil. This is exactly what happens to the blood of a submariner who is rapidly rising from the depth to the surface.

When a diver is at depth, he needs gas to breathe at a pressure at least equal to that of the environment. Suppose a diver is at a depth of 30 meters. Therefore, for normal breathing at such a depth, the pressure of the inhaled gas mixture should be equal to: (30m / 10m) atm. + 1 atm. = 4 atm.
that is, four times the pressure on land. At the same time, the amount of nitrogen dissolved in the body, over time, increases and, ultimately, also exceeds the amount of dissolved nitrogen on land by four times.

Upon ascent, with a decrease in the external, hydrostatic pressure of the water, the pressure of the gas mixture, which the diver breathes, also begins to decrease. The amount of nitrogen consumed by the diver, or rather its partial pressure, also decreases. Because of this, a blood oversaturation with nitrogen begins to occur, as a result of which it begins to slowly be released in the form of micro bubbles. There is a "desaturation" of the blood, which at the same time, as it were, "boils". An inverse gradient of gas diffusion from liquid is created. When the ascent process is slow, the partial pressure of nitrogen in the breathing mixture also decreases slowly - relative to the breathing of the diver. Micro bubbles of nitrogen, from the blood, begin to be released and, together with the bloodstream, move into the heart, and from there into the lungs, where they, again, through the walls of the alveoli, go out during exhalation.

If the diver begins to float up too quickly, then the nitrogen bubbles simply do not have time to reach the lungs and leave the body. The submariner's blood "boils". Thus, more and more dissolved nitrogen is added to the bubbles, which creates the effect of a snowball rolling downhill. Then platelets are attached to the bladders, followed by other blood cells. This is how local blood clots (thrombi) are formed, making it unevenly viscous and capable of even blocking small vessels. Meanwhile, the bubbles attached to the inner walls of blood vessels partially destroy them and come off along with their pieces, which complement the "barricades" in the bloodstream. A break in the walls of blood vessels leads to hemorrhage into the surrounding tissues, blood flow slows down, and the blood supply to vital organs is disrupted. Large clusters of bubbles, when combined with each other, can cause a very serious disease of gas embolism.

Extravascular DCS occurs when microbubbles that form in tissues, joints, and tendons attract nitrogen released from tissues during ascent, but cannot enter the bloodstream due to its blockage (the so-called "bottleneck effect"). Hydrophilic tissues of joints and ligaments are especially susceptible to the accumulation of extravascular nitrogen bubbles. It is this type of DCS that causes joint pain - a classic symptom of decompression sickness. Growing blisters press on muscle fibers and nerve endings, which leads to serious damage internal organs.

Mechanical blockade of blood flow by nitrogen bubbles is not the only mechanism of decompression sickness. The presence of bubbles and their connection with blood cells leads to biochemical reactions that stimulate blood clotting directly in the vessels, the release of histamines and specific proteins into the blood. Selective removal of complementary proteins from the blood eliminates the danger of many of the destructive consequences of DCS. Recent studies have shown that the binding of blisters to white blood cells causes severe vascular inflammation. Thus, immunological factors and biochemical reactions play a very important role in the development of the disease.

To avoid the occurrence of DCS, it is necessary, first of all, to control the ascent process, which, according to modern concepts, should not exceed 18 meters per minute. The slower the diver ascends, the slower the ambient pressure decreases and the fewer bubbles form in his blood. Excess gas has time to escape through the lungs without causing harm to the body.

Moreover, in the practice of diving, there are so-called decompression stops. Their essence lies in the fact that a diver, rising from depth to the surface, stops at a certain - obviously lower than the diving depth - depth at, again, a certain time, which is calculated either from tables or using a diving computer. This stop (or even several gradual stops) can last for a rather long period of time, depending directly on how much the diver has exceeded the no-decompression limit of diving, and, accordingly, on how highly nitrogenated his body is. During such stops, the body is "desaturated" and gas bubbles are removed from it. Excess nitrogen is removed from the body, and the blood does not boil, as if the swimmer floated to the surface without any stop. Often at such stops, the submariner breathes a gas mixture different from the "bottom" one. In such a mixture (stage), the percentage of nitrogen is reduced, and therefore decompression is faster.

Of course, the complete saturation of all body tissues with nitrogen does not occur immediately, this takes time. To calculate the maximum time spent at a "given" depth, without the risk of DCS, there are special decompression tables, which have recently begun to replace dive computers everywhere. Using these tables, you can approximately find out the time spent by a diver at a "given" depth - when breathing a "given" gas mixture - which will be safe from the point of view of health. The word "approximately" is not accidental here. Data on finding at a certain depth, for different people, can vary over a very wide range. There are certain risk groups for which diving times can be significantly shorter than others. For example, a severely dehydrated human body is much more susceptible to DCS, so all divers drink a lot of fluids, before and immediately after diving. Decompression tables and dive computers initially contain a certain margin of "safety", focusing on the minimum possible time dives after which there is already a risk of DCS.

Cold and physical exercise during diving also contribute to the onset of DCS. Blood circulates more slowly in the frozen part of the body and is much less exposed to the removal of excess nitrogen from it, as well as from adjacent tissues. After surfacing in such places, the so-called cellophane effect can be observed, which is created by the bubbles that did not come out under the skin.

One of the options for reducing the risk of DCS, as well, is the use of breathing mixtures other than air. The most common variant of this mixture is Nitrox - enriched air. In nitrox, in comparison with plain air, the percentage of oxygen is increased, due to the lower content of nitrogen. Since nitrox contains less nitrogen, then, accordingly, the time spent at a given depth will be more than the time at the same depth, but using air. Or vice versa: it will be possible to stay under water for the same time as in "air", but at a greater depth. Due to the lower nitrogen content in nitrox, the body is less saturated with it. When diving with nitrox, you need to use your own, nitrox, decompression tables or special computer modes.
Since nitrox contains more oxygen than air, another danger arises - oxygen poisoning. The nitrox brand (the percentage of oxygen in it) determines the maximum depth to which you can dive without the risk of oxygen poisoning. For the use of enriched air for diving, there are special courses within all international diving associations.

Risk group

The risk groups for DCS today have increased significantly in comparison with the 19th century. This group now includes not only divers and workers working in caissons, but also pilots who experience pressure drops during high-altitude flights and astronauts who wear low-pressure suits for spacewalk.

Factors provoking DCS

Violation of the regulation of blood circulation under water.
Aging of the body is expressed in the weakening of all biological systems, including the cardiovascular and respiratory systems. This, in turn, is reflected in a decrease in the efficiency of blood flow, cardiac activity, etc. Therefore, the risk of DCS increases with age.
Overcooling of the body, as a result of which blood flow, especially in the limbs and in the surface layer of the body, slows down, which favors the onset of decompression sickness. Eliminating this factor is quite simple: when diving, you need to wear a sufficiently warm wetsuit, gloves, boots and a helmet.
Dehydration of the body. Dehydration is expressed as a decrease in blood volume, which leads to an increase in blood viscosity and a slowdown in circulation. This also creates favorable conditions for the formation of nitrogen "barricades" in the vessels, general disturbance and arrest of blood flow. Many reasons contribute to dehydration of the body during scuba diving: sweating in a wetsuit, humidification of dry air from scuba gear to oral cavity, increased urination in a submerged and cooled state. Therefore, it is recommended to drink as much water as possible before and after diving. Dilution of blood accelerates its flow and increases its volume, which has a positive effect on the process of removing excess gas from the blood through the lungs.
Exercise before diving causes the active formation of "quiet" bubbles, uneven dynamics of blood flow and the formation of circulatory system zones with high and low pressure. Experiments have shown that the number of microbubbles in the blood decreases significantly after resting in the supine position.
Physical activity during a dive leads to an increase in the speed and unevenness of blood flow and, accordingly, to an increase in nitrogen absorption. Heavy physical exercises lead to the deposition of microbubbles in the joints and prepare favorable conditions for the development of DCS during subsequent immersion. Therefore, it is necessary to avoid strenuous physical activity before, during and after the dive. Moreover, physical activity increases sugar consumption, which leads to heating of tissues and to an increase in the rate of release of an inert gas - an increase in the voltage gradient.
Overweight divers are at a greater risk of contracting decompression sickness (compared to normal-build divers), as their blood is high in fat, which, due to its hydrophobicity, increases the formation of gas bubbles. In addition, lipids (adipose tissue) dissolve and retain inert gases most readily.
One of the most serious DCS provoking factors is hypercapnia, due to which the acidity of the blood sharply increases and, as a consequence, the solubility of the inert gas increases. Factors provoking hypercapnia: physical activity, increased breathing resistance and holding the breath to "save" DHS, the presence of contaminants in the inhaled DHS.
Drinking alcohol before and after a dive will cause severe dehydration, which is an unquestionable contributor to DCS. In addition, the molecules of alcohol (solvent) are those "centers" that cause the sticking together of "quiet" bubbles and the formation of the main gas body - a macrobubble. The main danger of alcohol consumption is its rapid dissolution in the blood and the subsequent rapid onset of a pathological condition.

Diagnostics

Decompression sickness is sometimes confused with arthritis or injury. The latter are accompanied by redness and swelling of the limb; arthritis, on the other hand, usually occurs in paired limbs. Unlike decompression sickness, in both cases, movement and pressure on the injured area increase the pain. Severe decompression sickness affects vital organs and systems human body: brain and spinal cord, heart, hearing organs, nervous system, etc. According to US medical statistics, almost 2/3 of those affected by decompression sickness had one or another neural form. The spinal cord is most often affected. Defeat spinal cord occurs when its blood supply is disturbed as a result of the formation and accumulation of bubbles in the surrounding fatty tissues. The bubbles block the blood flow that feeds the nerve cells and also put mechanical pressure on them.

The entry of bubbles from the aorta into coronary arteries supplying blood to the heart muscle, leads to cardiac disorders, the end of which can be myocardial infarction. The pulmonary form of decompression sickness is very rare and only in divers who dive to significant depths. Many bubbles in venous blood block blood circulation in the lungs, making it difficult to exchange gas (both oxygen consumption and nitrogen release). The symptomatology is simple: the patient feels shortness of breath, suffocation and chest pain.

First aid

Any health care starts with checking general condition, pulse, respiration and consciousness, as well as keeping the patient warm and immobile. In order to provide first aid to a victim of DCS, it is necessary to determine its symptoms. Among them are "soft", such as severe unexpected fatigue and itchy skin, which are eliminated with pure oxygen, and "serious" - pain, disturbance of breathing, speech, hearing or vision, numbness and paralysis of the limbs, vomiting and loss of consciousness. The occurrence of any of these symptoms suggests a severe form of DCS.

If the victim is conscious and shows only "mild" symptoms, it is better to put him on his back horizontally, avoiding a position that impedes blood flow in any limb (crossing the legs, putting hands under the head, etc.). A person with impaired lungs feels most comfortable in a motionless sitting position, which saves him from suffocation. In other forms of the disease, a sitting position should be avoided, bearing in mind the positive buoyancy of nitrogen bubbles.

A diver with severe disease symptoms should be placed differently. Since an unconscious victim may vomit (and when lying on his back, vomit can enter the lungs), in order to prevent overlapping respiratory tract vomit, he is placed on his left side, bending his right leg at the knee for stability. If the victim's breathing is impaired, the patient should be put on his back and artificial respiration, and if necessary, an indirect heart massage.

After the patient has been helped to take the correct position, he needs to provide breathing with pure oxygen. This is the main and most important first aid technique until the moment you transfer the victim to the hands of a specialist. Oxygen breathing creates favorable conditions for the transport of nitrogen from the bladders to the lungs, which reduces its concentration in the blood and body tissues. To provide first aid to patients with DCS, special compressed oxygen cylinders are used, equipped with a regulator and a mask with an oxygen supply of 15-20 l / min. They provide breathing with almost one hundred percent oxygen, and a transparent mask allows you to notice the appearance of vomiting in time.

Transportation of the patient to the pressure chamber. Air travel should be avoided, as at high altitudes the blisters will increase in volume, which will aggravate the disease. Hemorrhages in the most severe forms of decompression sickness lead to the leakage of blood plasma into the tissue, and this loss must be compensated. Make a patient with "mild" symptoms drink a glass of water or any non-alcoholic non-carbonated beverage every 15 minutes. Remember, however, that acidic drinks like orange juice can cause nausea and vomiting. A person who is in a semi-conscious state or periodically loses consciousness is not recommended to drink.

Treatment

Treatment is carried out by recompression, that is, by increasing and then gradually lowering the pressure according to special tables. The recompression regimen is selected by specialists in accordance with the specific form of DCS, the period since the rise or after the first onset of symptoms, and a number of other factors. In order to distinguish decompression sickness from gas embolism, a test increase in pressure is carried out to a level corresponding to a depth of 18 meters for a period of 10 minutes in combination with oxygen breathing. If the symptoms disappear or subside, then the diagnosis is correct. In this case, the main recompression mode is selected according to the tables. Most often, they start with a simulated dive to 18 meters and a gradual ascent lasting from several hours to several days. All this time, the patient sits in a pressure chamber in a mask and breathes pure oxygen with periodic five-minute breaks, since continuous breathing with pure oxygen for 18-24 hours leads to oxygen poisoning. Carelessness in calculating the treatment regimen threatens to exacerbate symptoms and further develop DCS.

In an extreme situation, when it is not possible to immediately transport the victim to the appropriate nearest pressure chamber, it is possible to perform partial therapeutic recompression using pure oxygen, a transport balloon with 50% nitrox, a full face mask and a decompression station. This procedure takes a lot of time and is practically impossible under conditions cold water... The onset of oxygen poisoning can be controlled with an air pause, but even if convulsions occur, with a full face mask and under the supervision of a partner, they are not so dangerous and the risk of drowning is minimal. By themselves, convulsions do not have a decisive effect on the body.

It should be noted inefficiency use of air or other bottom DHS for recompression - in the case of its application, a partial reduction in symptoms is accompanied by ongoing dissolution and accumulation of an inert gas in the tissues, which ultimately leads to deterioration states. This procedure cannot be recommended also because the condition of a person prone to DCS symptoms unpredictable and sharp deterioration it will lead to drowning under water, while on the surface this condition can be controlled for a long time. Thus, the recommended decompression for bottom gas is an unforgivable waste of time and dangerous risk... In any case, therapeutic recompression at the dive site will only reduce symptoms and allow the victim to be taken to a stationary barocomplex for recovery.

Decompression sickness is a topic that you should know the trick well enough. It always seems to us that trouble can happen to anyone, but not to us. But, unfortunately, this disease is not uncommon, moreover, the "box" is a rather scary thing. Here are a few examples when tricks caught decompression sickness at a rather harmless depth.

Underwater hunter V. had to surface very quickly from a depth of 30 meters with a total diving time of 40 minutes. 4 hours after surfacing V. felt pain in the hip joint. They got stronger and stronger. But V. did not assume that he could be seized by decompression sickness, so he turned to the doctor only 28 hours after surfacing, when the pains became unbearable. The result is a therapeutic recompression in the chamber for 14 hours.

Experienced instructor E. worked quite far from the nearest recompression chamber. He dived to a depth of 43 meters in 45 minutes, collecting animals. Then E. went up to the boat, gave up the animals, but did not dive for holding exposures in the water. At night E. felt unwell and itchy, and in the morning he discovered partial paralysis of his leg. The therapeutic recompression in water did not improve the situation. And only a day later he was taken to the recompression chamber, where he had to stay for 39 hours.

Decompression sickness. Causes

Caisson disease occurs in a person during the transition from high to low pressure. The "caisson" develops in people who are in such an environment without prior preparation. An abrupt transition from high blood pressure to normal pressure is especially dangerous.

Signs and symptoms

In mild cases, you may notice general weakness, itching, tinnitus, joint and muscle pain. In more severe cases, there is paralysis, shortness of breath, dizziness, loss of consciousness, cyanosis, paresis, subcutaneous emphysema, collaptoid state. In the worst case, death is possible.

First aid for decompression sickness

The most effective method to heal the caisson is recompression. It consists in placing the patient again in an atmosphere with increased pressure, and then slowly transferring to an environment with normal pressure.

For this, special cameras are used. If it is not possible to place the victim in such a chamber, do artificial respiration, give oxygen or carbogen (93 parts of oxygen and 7 parts of carbon dioxide). In case of cardiovascular insufficiency, camphor, caffeine, cordiamine are administered. In case of depression of the respiratory center - cytiton or lobelia.

Prevention of decompression sickness:

Continuous monitoring of exposure to increased pressure
No alcohol intake before diving
Not diving when tired or feeling unwell
Good ventilation of the spacesuit
Limiting the time spent under pressure, taking into account the depth.

The permissible pressure in the caisson should not exceed 4 atm, which is a water depth of 40 meters. By following these rules, you can minimize the likelihood of a caisson.

Decompression sickness (decompression sickness) is an occupational disease characterized by the formation of gas bubbles in the blood due to rapid decline pressure of the inhaled mixture of gases (nitrogen, helium, oxygen, hydrogen), which leads to the destruction of cell walls, blood vessels and blockage of blood supply to tissues. This pathology is also called "divers' disease" due to the fact that most often it is divers (especially amateurs) who suffer from this disease due to non-observance of due precautions.

With increasing pressure, the solubility of gases in liquids (in this case, in blood, lymph, synovial and cerebrospinal fluids) increases, while with a sharp decrease in pressure, gases dissolved in the liquid are released in the form of bubbles, which tend to group and block, destroy, squeeze vessels. Breakthrough of the vascular wall leads to hemorrhages in organ tissue. Also, bubbles can cluster and cause gas embolism. During the formation of extravascular vesicles (mainly in the hydrophilic tissues of the joints and ligaments), serious damage to internal organs can occur due to squeezing of muscle fibers and nerve endings by bubbles.

The risk group currently includes not only divers and caisson workers, but also pilots experiencing pressure drops during high-altitude flights, and astronauts using suits that maintain low pressure during spacewalks.

Factors that trigger the development of decompression sickness:

· A sharp rise to the surface from a depth without stopping;

· Air flight after deep diving;

• violation of the regulation of blood circulation at depth (under water);

Hypothermia of the body in conditions of increased pressure;

· Age-related changes (less efficient blood flow, weakened cardiovascular and respiratory systems);

· Dehydration of the body (slow blood flow contributes to the formation of "nitrogen barricades");

· Physical activity during the dive or before it;

· Drinking alcohol immediately before or after a dive;

· Overweight divers;

Hypercapnia (increased breathing resistance, physical activity, holding the breath to save the breathing mixture, contamination of mixtures).

Symptoms of decompression sickness

Clinical manifestations depend on the severity of decompression sickness. With a mild degree, skin rashes, itching, moderate pain in joints, bones and muscles, moderate weakness, awkwardness of movements, paresthesia (numbness, feeling of "creeping"), rapid breathing and pulse appear. With moderate severity, the general condition worsens almost immediately after decompression, the pain is intense, cold sweat, nausea, vomiting appear, bloating and short-term loss of vision may occur. With a severe degree of decompression sickness, symptoms of central lesion appear. nervous system(paralysis, paresis), musculoskeletal system and of cardio-vascular system(chest pain, cyanosis, collapse, suffocation), which can be fatal.

The diagnosis is usually based on clinical manifestations, examination of the patient and a carefully collected anamnesis (the presence of the fact of immersion under water, flight at high altitude, etc.). X-ray diagnostic methods make it possible to detect gas bubbles in the synovial bags, sometimes in the blood vessels, medullary dehydration (in bone marrow) and specific changes in the spine (expansion of the vertebral bodies, a decrease in their height in the absence of damage to the intervertebral discs).

There are two types of decompression sickness:

Type I - the lymphatic system, skin, muscles and joints are involved in the pathological process (lymphadenopathy, arthralgia and myalgia, rash and itching);

· II type - more life-threatening, with damage to the brain and spinal cord, respiratory and cardiovascular systems.

When the above symptoms appear, you must take horizontal position and call ambulance for transportation to a pressure chamber.

Treatment decompression sickness

The main method of treatment for decompression sickness is recompression (flushing of excess nitrogen with oxygen under high pressure in a pressure chamber). Symptomatic therapy is aimed at reducing pain, stimulating the cardiovascular system, preventing and eliminating complications. For this purpose, pain relievers, anti-inflammatory, restorative drugs, etc. can be prescribed.

Complications of decompression sickness can be varied depending on the severity and timeliness of the treatment. It can be deforming osteoarthritis, myodegeneration of the heart, aeropathic myelosis, chronic Menier's syndrome, acute heart and / or respiratory failure, neuritis optic nerve and defeat gastrointestinal tract, as well as death in the event of an extremely severe illness and lack of medical care.

Prophylaxis decompression sickness

In order to prevent the development of decompression sickness, gas mixtures with a high oxygen content are used, they adhere to the method of ascent from a depth, temporarily avoid staying in conditions of low pressure after a dive, and carry out desaturation (nitrogen removal) in decompression chambers.

Decompression sickness - one of those that are among the so-called "occupational" diseases. The correct name in medical reference books sounds like decompression sickness, or DCS. In common parlance, it is often called the "disease of divers", and the diving enthusiasts themselves capaciously call this disease "kessonka". What is this unusual disease characteristic of those who often descend to the depths of the sea or underground?

History and description of the disease

DCS is a disease caused by a sharp decrease in the pressure of gases inhaled by a person - nitrogen, oxygen, hydrogen. At the same time, dissolved in human blood, these gases begin to be released in the form of bubbles, which block the normal blood supply, destroy the walls of blood vessels and cells. In a severe stage, this disease can lead to paralysis or even death. This condition often develops in those who work in conditions of high atmospheric pressure during the transition from it to normal pressure without taking due precautions. This transition is called decompression, which gave the name to the disease.

Such decompression is experienced by workers involved in the construction of bridges, ports, foundations for equipment, digging underwater tunnels, as well as miners involved in the development of new deposits and divers, both professionals and amateurs of underwater sports. All these works are carried out under compressed air in special caisson chambers or in special immersion suits with an air supply system. The pressure in them is intentionally increased with immersion in order to balance the growing pressure of the water column or water-saturated soil above the chamber. Staying in caissons, like scuba diving, consists of three stages:

Compression (pressure rise period);
Working in a caisson (staying under a consistently high pressure);
Decompression (period of pressure reduction when climbing up).

It is with the wrong passage of the first and third stages that decompression sickness occurs.

A potential risk group is recreational divers. Moreover, news reports often talk about how military doctors have to “pump out” reckless divers.

For the first time, mankind faced this disease after the invention of the air pump and chamber-caisson in 1841. Then workers began to use such cameras when building tunnels under rivers and fixing bridge supports in wet soil. They began to complain of joint pain, limb numbness and paralysis after the chamber returned to normal 1 atmosphere pressure. These symptoms are currently referred to as type 1 DCS.

Typology of decompression sickness

Doctors currently divide decompression sickness into two types, depending on which organs are involved in the symptoms and the complexity of the course of the disease.

Type I decompression sickness is moderately life-threatening. In this type of disease, the joints, lymphatic system, muscles and skin are involved. The symptoms of type 1 decompression sickness are as follows: increasing joint pain (elbow, shoulder joints suffer in particular), back and muscles. Painful sensations become stronger with movement, they acquire a boring character. Other symptoms are itchy skin, rash, also with this type of disease, the skin becomes covered with spots, lymph nodes are enlarged -.
Type II decompression sickness is much more dangerous for the human body. It affects the spinal cord, brain, respiratory and circulatory systems. This type is manifested by paresis, difficulty urinating, intestinal dysfunction, tinnitus. In especially difficult cases, there may be loss of vision and hearing, paralysis, convulsions with the transition to a coma. Choking occurs less often (shortness of breath, chest pain, cough), but this is a very alarming symptom. With a long stay of a person in rooms with high pressure, such an insidious symptom as dysbaric osteonecrosis is possible - a manifestation of aseptic bone necrosis.

Decompression sickness manifests itself within an hour after decompression in 50% of patients. These are especially often the most severe symptoms. In 90%, signs of the development of decompression sickness are detected 6 hours after decompression, and in rare cases (this applies primarily to those who, after leaving the caisson, rise to a height), they can appear even after a day or more.

The mechanism of the "problem of divers"

To understand the causes of this disease, one should turn to Henry's physical law, which says that the solubility of a gas in a liquid is directly proportional to the pressure on this gas and liquid, that is, the higher the pressure, the better the gas mixture that a person breathes in the blood dissolves. And the opposite effect - the faster the pressure decreases, the faster the gas is released from the blood in the form of bubbles. This applies not only to blood, but also to any fluid in the human body, therefore decompression sickness also affects the lymphatic system, joints, bone and spinal cord.

The gas bubbles formed as a result of a sharp decrease in pressure tend to group and block vessels, destroy tissue cells, vessels, or squeeze them. As a result, blood clots form in the circulatory system, which rupture the vessel and lead to its necrosis. And bubbles with blood flow can enter the most distant organs of the human body and continue to carry destruction.

The main causes of decompression sickness during diving are as follows:

Abrupt non-stop ascent to the surface;
Immersion in cold water;
Stress or tiredness;
Obesity;
The age of the diving person;
Flight after deep diving;

When diving in a caisson, the common causes of decompression sickness are:

Long-term work in conditions of high pressure;
Diving in a caisson to a depth of over 40 meters, when the pressure rises above 4 atmospheres.

Diagnostics and treatment of decompression sickness

For a correct diagnosis, the physician is required to provide a complete clinical picture of the symptoms that arose after decompression. Also, a specialist in diagnostics can rely on data from such studies as magnetic resonance imaging of the brain and spinal cord to confirm the diagnosis by characteristic changes in these organs. However, you should not rely solely on these methods - the clinical picture may coincide with the course of arterial gas embolism. If dysbaric osteoncrosis has become one of the symptoms, then only a combination of radiography can reveal it.

Decompression sickness is safely cured in 80% of cases. To do this, it is necessary to take into account the time factor - the faster the symptoms are identified and the treatment is provided, the faster the body will recover and remove gas bubbles.

The main treatment for DCS is recompression. For this, special equipment is used that supplies a large amount of oxygen to the patient's blood in order to flush out excess nitrogen under increased pressure. This method is used right at the location of the victim, later it is important to transport him to the nearest medical institution... In the future, therapy is added to eliminate other symptoms of the disease - relieving joint pain, restorative and anti-inflammatory therapy.

A decompression chamber used to treat decompression sickness.

In order to prevent DCS, the decompression regime should be correctly calculated, the correct intervals between decompression stops should be set during the ascent to the surface, so that the body has time to adapt to the changing pressure. Most often, these calculations are carried out by computer programs designed for these purposes, but in 50% of cases they do not take into account the individual characteristics of each diver or working caisson chamber, as well as the fact that many of them are negligent in fulfilling the recommendations for the correct ascent from the area high pressure to the surface.

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Caisson disease is a pathological condition that progresses as a result of a person's transition from an area with increased atmospheric pressure to an area with normal performance... The disorder gets its name from the transition from high blood pressure to normal. Often, divers and miners who are at depth for a long time are prone to this disorder.

The disease develops as a result of a sharp decrease in the pressure of substances such as nitrogen, oxygen and hydrogen. Dissolving in the blood, they form small bubbles that can interfere with normal blood circulation, which leads to the destruction of blood vessels and cells. With a severe course, such a disease can lead to death.

The clinical manifestations of the disease directly depend on the severity of its course. On initial stages decompression sickness, symptoms such as muscle and joint pain, rashes on the skin, frequent heartbeat and breathing. With a moderate course, nausea, an increase in the size of the abdomen, and a decrease in visual acuity may be expressed. As the disorder progresses, convulsions begin to appear, damage to the cardiovascular system,.

Diagnosis is based on clinical manifestations, a thorough examination of the victim and the collection of detailed information about dives to depths or stays at high altitudes. Treatment is aimed at reducing the amount of nitrogen in the body and eliminating the signs of the disease.

Etiology

The main factor in the progression of decompression sickness is an abrupt change in pressure. As a result of a change in the environment in the bloodstream, bubbles of gas are formed, which can be grouped, and cause blockage of blood vessels, destruction of tissues, or, conversely, their excessive compression. As a result, blood clots are formed, which rupture the vessels and lead to their death. Bubbles with blood flow can enter any organs of the human body and lead to disruption of their normal functioning.

The predisposing factors for the onset of this disease are:

a sharp rise to the surface;
immersion in too cold water;
the impact of stressful situations and fatigue;
excessively high body weight;
the age category of the person submerging under the water. It is believed that the older the person is, the higher the likelihood of developing this disorder;
flight a few hours after submersion;
drinking alcohol before or after diving.

The risk group is not only divers, divers or miners working at depth, but also pilots who experience significant pressure drops when flying at high altitude.

Varieties

Depending on the intensity of the manifestation of symptoms, there are several stages of the course of decompression sickness:

mild - manifested by slight soreness in the joints, muscles;
moderate - signs are dizziness, nausea, temporary loss of vision;
severe - convulsions (a substance in the spinal cord is involved in the disease process), systemic speech impairment;
lethal - symptoms develop against the background of acute or circulatory disorders of the brain.

In addition, there are two types of the disease:

first - the process involves the lymph nodes, skin, muscles, joints;
the second - there is damage to the brain and spinal cord, respiratory and cardiovascular systems.

Symptoms

As decompression sickness progresses, the patient's general condition worsens and more serious symptoms appear. Light form expressed:

the occurrence of skin rash and itching;
general weakness of the body;
soreness in muscles and joints;
decreased visual acuity;
the development of oxygen deficiency begins.

With the course of a disorder of moderate severity, symptoms such as:

indigestion;
temporary loss of vision;
attacks of severe dizziness;
nausea, often accompanied by vomiting;
increased sweating;
an increase in the volume of the abdomen;
rapid breathing and palpitations.

At more severe stages of the disease, the following symptoms appear:

paralysis and paresis;
convulsions;
chest pain;
suffocation;
speech impairment.

In the lethal form, the presence of multiple blockages of blood circulation is noted, which can cause death.

Complications

The consequences of decompression sickness are individual for each person and are manifested depending on the form and severity of the disease, as well as on the timeliness of the treatment begun. Possible complications I can be:

heart and respiratory failure;
- violation of the articular cartilage;
multiple lesions of the gastrointestinal tract;
inflammation of the optic nerve.

Lethal outcome occurs when severe course diseases, as well as due to the failure to provide medical care.

Diagnostics

Diagnosis of decompression sickness for a qualified specialist will not be difficult, since the pathology develops within several hours after an ascent from a depth or landing. For a correct diagnosis, the doctor must provide full information about the first time and intensity of the manifestation of symptoms. In addition, a complete examination of the patient, measurement of pulse and blood pressure is carried out.

The basis diagnostic activities make up hardware examinations, such as:

X-ray - allows you to detect changes in the structure of bones, joints and spinal cord;
CT and MRI - make it possible to detect gas bubbles and changes in the spine.

Blood tests for this disease have no diagnostic value. After receiving all the results of the examinations, the doctor determines which method of treating this disease is the most effective.

Treatment

After confirming the disease, therapy should be started as soon as possible. Any delay can lead to development dangerous consequences or death. In the initial stages, the disorder is eliminated by inhaling oxygen through a mask. With a more severe course, treatment in a pressure chamber is necessary. In this device, at first, the pressure gradually increases and then decreases. This action causes the gas bubbles in the blood to dissolve.

Drug therapy is aimed at reducing pain, stimulating the cardiovascular system. It is also used as a prophylaxis and to eliminate complications. For this, pain relievers, substances that strengthen the immune system, anti-inflammatory medicines are prescribed. Physiotherapy methods can be used, in particular water or dry air baths. With timely initiation of treatment, in almost all cases, it is possible to completely eliminate decompression sickness.

Prophylaxis

This disease can be prevented by:

reducing the duration of dives to depth;
restrictions on flights and diving during pregnancy, after drinking alcohol, in the presence of heart problems;
avoidance of repeated deepening within twelve hours, flights - during the day.

In addition, it is important to always use professional equipment and special suits, oxygen cylinders. If you experience the first symptoms, immediately consult a doctor.

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Diseases with similar symptoms:

The disease, which is characterized by the formation of pulmonary insufficiency, presented in the form of a massive release of transudate from the capillaries into the pulmonary cavity and, as a result, contributing to the infiltration of the alveoli, is called pulmonary edema. In simple terms, pulmonary edema is a situation when fluid stagnates in the lungs that has seeped through blood vessels... The disease is characterized as an independent symptom and can be formed on the basis of other serious ailments of the body.