Decompression Sickness

What is Decompression Sickness?

Decompression sickness is the condition that arises due to the rapid decrease in pressure due to the dissolved gases that come out of the solution as bubbles and cause depressurization in the body. It is normally caused by an uncontrolled or an emergency ascent while one is diving. It is also known as the Diver’s disease, Caisson disease or the Bends decompression sickness disease. This disease is particularly experienced by the scuba divers on very poorly managed ascent, or aviators who fly in those aircraft which are pressurized inadequately.

Decompression Illness is a term that is used for a condition in which both decompression Sickness and Lung Expansion Injury are clumped under. This is due to the reason that both these diseases have similar medical treatment and they are almost identical. Decompression Sickness is a Diving disorder as the divers are caught up with this disease, since they may very often breathe a gas that is at a higher pressure than the pressure that is prevailing in the surrounding areas. This condition manifests those people those who have undergone frequent decompressions.

Decompression Sickness Definition

Decompression Sickness is a fatal condition that occurs due to the formation of nitrogen bubbles and precipitation of dissolved gases and bubbles in the body due to depressurization, and is mostly noticed in case of deep sea-divers and aeronauts.

Decompression Sickness Classification

The classification of the Bends Decompression Sickness is mostly according to its symptoms. Earlier people used to describe this disease by different conditions. They described it as bends when the pain would occur in the joints, as staggers, if there was some sort of neurological problem, and Chokes, if the person faced breathing problem. Decompression Sickness is classified as type 1, type 3 or type 3.

Decompression Sickness Type 1

This is the least serious type of Decompression Sickness. This takes the form of pain in the joints and in the body. This type cannot be termed as a life threatening one, although treatment measures need to be taken at this stage itself, or else it may progress to type 2. It characterizes itself in the following ways:

  • Pain in the joints and loss of function of the joints
  • Mild pain in the body
  • Bends in the skin, that may cause burning sensation or itching in the skin
  • Skin rashes, mottling, and swelling of the lymphs

This type of sickness occurs when there is an outflow of nitrogen bubbles from the solution and reaches the skin capillaries. This results in the formation of a red rash on the chest and the shoulders. Since this type causes pain in the joints, it is very essential to know that this pain is primarily caused due to the bubbles aggravating the bone marrow, tendons and the joints.

Decompression Sickness Type 2

The type 2 of Decompression Sickness is basically a serious form of this disease. It is characterized by an involvement of the nervous system in the pulmonary problems, circulatory problems and the lung symptoms. In this type decompression, pain is reported only for about 30% of the cases. Since the anatomy of the central and the peripheral nervous system is very complex, there are variations in the symptoms and signs of this disease.

Some of the common symptoms that appear on the occurrence of this type of decompression are:

  • Back pain
  • Incontinence or retention
  • Paresthesia
  • Loss in the control of the urinary sphincter

This condition can be classified as a life-threatening one, since it may go to the extent of causing a respiratory collapse. The main effects that ot causes are:

  • Neurological Decompression sickness
  • Cerebral Decompression Sickness
  • Pulmonary Decompression Sickness.

Decompression Sickness Type 3

This type of sickness is basically a combination of the AGE and decompression sickness with some neurological symptoms. It is a very serious condition and may go to the extent of causing a serious threat to life of the individual.

Decompression Sickness Symptoms

Decompression sickness is mostly observed in the knees, shoulders, ankles and in the joints. It manifests itself in many ways. The most common symptoms of the Decompression Sickness are:

  • Red rash on the skin
  • Numbness
  • Dizziness
  • Blurred vision
  • Confusion
  • Vertigo
  • Stomach Sickness
  • Extreme fatigue
  • Heart problems
  • Ringing of the ears
  • Pain in the joint and limbs
  • Unconsciousness
  • Headache and nausea
  • Respiratory problems
  • Blurred vision
  • Weakness in the hands and legs
  • Numbness and tingling
  • Chest pain due to lung rupture
  • Paralysis in severe cases
  • Shortness of breadth
  • Itching
  • Feeling of tiredness

Signs of Decompression Sickness

There are certain signs that may demonstrate the occurrence of the decompression sickness. The most commonly occurring signs of decompression sickness are:

  • Staggering
  • Amnesia
  • Tremors
  • Collapse and unconsciousness
  • Blood in cough
  • Blotchy rash
  • Problem in urination
  • Problem in urination
  • Personality changes
  • Frothy sputum
  • Instability
  • Spasms of cough

Decompression Sickness History

The history of decompression sickness is very long. It was first experienced in 1670. Robert Boyle was the first one who demonstrated that a reduction in pressure can lead to the formation of bubbles in a living being. In 1769, Giovanni Morgagni described that the cause of death of a dead body was cerebral circulation. Then during 1870 to 1910, all the prominent features were established. In 1908, JS Haldane published “the Prevention of Compressed Air Illness”.  There was a similarity between the decompression sickness and the iatrogenic air that was noticed.

Decompression Sickness Causes

The primary cause of Decompression Sickness is the reduction in ambient pressure, due to which there is a formation of bubbles and some inert gases inside the tissues of the body. This condition also happens when a person leaves a high-pressure environment, or when he moves from a lower altitude to a higher one.

The main causes of this disease can be discussed in detail:

Leaving a High-pressure environment

There are certain regions, where this condition is particularly common. If a person comes out from a pressurized mine, he may experience a reduction in the atmospheric pressure. Similarly when astronauts come out from a space vehicle, for an extra-vehicular space activity, they experience a similar situation.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Ascent from Depth

This is the diver’s disease, affecting the divers who breathe a gas which is at a relatively higher pressure than the surface pressure. As the divers dive at a greater depth for a long period, the risk of Decompression sickness increases. Sometimes, when divers try breadth-holding, the risk of  Decompression Sickness increases.

Ascent to Altitude

Sometimes, when suddenly, an unpressurized aircraft ascends to a higher altitude, Decompression sickness becomes a very common problem in such a situation. Actually, there is no specific altitude that can be considered safe for everyone.

Decompression Sickness Aviation

This problem is commonly observed in case of aeronauts and aircraft flights. The technology today is such that the airplanes fly much faster than ever before. But as there is continuous increase in the flight of these planes, the risk of Decompression Sickness is continuously increasing. The problem of depressurization is continuously increasing.

Decompression Sickness Diagnosis

Generally, you can detect this condition, if you notice any of the symptoms of this disease occurring, due to a drop n pressure within 24 hours of diving. However, if the symptoms begin more than 6 hours following decompression, then alternative diagnosis method should be looked for.  MRI scans or CT scans can identify bubbles, still they are not very good methods of diagnosis.

Decompression Sickness Prevention

It is very important to prevent the Decompression Sickness, since it can lead to serious consequences in future, if allowed to continue. Some of the ways of preventing this condition are:

Diving

If the divers want to prevent the formation of bubbles, then they can limit the rate of their ascent to about 10 meters per minute, and may also carry a decompression schedule, as that may help. This schedule can help them, since this schedule allows the under-sea divers to carry the schedule that tells them whether they should remain at a particular depth, or move to a higher altitude, until there is an elimination of a particular amount of gas from the their body, before they can ascend to a higher altitude.

However, it is not always recommended to use a schedule for decompression sickness, since it does not completely protect one against this condition. Therefore the use of certain algorithms is preferable since these algorithms are designed in such a way, that they reduce the probability of decompression sickness to a very low level, but it does not completely reduce it to zero.

Exposure to high Altitude

Another very important way of preventing decompression sickness is Pre-breathing.  If one breathes pure oxygen, then there is a significant reduction in the nitrogen loads in the body tissue. This technique also offers protection upon the exposure to low-barometric pressure environments. But even this method has a drawback, due to which it cannot be availed by al. It is a comparatively expensive method, and logistically complicated, and therefore it is not always used.

Decompression Sickness Treatment

Whenever there is a case of decompression sickness, it should be treated with 100% oxygen treatment. This process should be continued until a hyperbaric oxygen therapy can be provided to the person suffering from this disease. Sometimes, if the conditions are mild, then it often disappears on the descent from the higher altitude. If the conditions seem to worsen, then only hyperbaric oxygen therapy can help.

Another effective method of treatment was the recompression on room air. This technique also utilizes oxygen, and is considered to be a standard care of this problem. Oxygen therapy has always increased the success of the recompression therapy. Sometimes, dehydration also helps. It is very beneficial to give fluids to the patient. Apart from this, Trendelenburg position and lateral decibitus position have also proved to be beneficial.  But it is not recommended for extended periods, since it may lead to cerebral edema problems.

Decompression Sickness Prognosis

If the correct treatment procedure, with recompression therapy and 100% oxygen treatment is followed, then there is no long term effect. But if there is a sort of long term injury from this disease, then it may even result in death. It may even lead to neurological sequelae in extreme cases.

Decompression Sickness Epidemiology

Decompression Sickness is a relatively rare disease, and its incidence is relatively more in males than in females. This disease affects the scuba divers in the US. Some of the people suffering from this disease also contain incidents of Arterial Gas Embolism. It is a fatal condition, when allowed to thrive. Therefore, adequate prevention measures must be taken to prevent the occurrence of this condition.

References:

http://en.wikipedia.org/wiki/Decompression_sickness

http://www.emedicinehealth.com/decompression_syndromes_the_bends/article_em.htm

http://www.thescubasite.com/Learn-To-Scuba-Dive/decompression-sickness-decompression-illness

http://www.wisegeek.com/what-is-decompression-sickness.htm

http://scuba.about.com/od/divemedicinesafety/

http://www.scuba-diving-smiles.com/scuba-diving-bends.html

Published on June 30th 2011 by  under Public Health.
Article was last reviewed on 30th August 2011.

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