Permanent neurologic problems, such as partial paralysis, often result from delayed or inadequate treatment of spinal cord symptoms. However, sometimes the damage is too severe to correct, even with appropriate and timely treatment.
Repeated treatments with oxygen in a high-pressure chamber seem to help some people recover from spinal cord damage. Doctors recognize decompression sickness by the nature of the symptoms and their onset in relation to diving. Tests such as computed tomography CT or magnetic resonance imaging MRI sometimes show brain or spinal cord abnormalities but are not reliable.
MRI is usually diagnostic of dysbaric osteonecrosis. Divers try to prevent decompression sickness by avoiding gas bubble formation. They do this by limiting the depth and duration of dives to a range that does not need decompression stops during ascent called no-stop limits by divers or by ascending with decompression stops as specified in authoritative guidelines, such as the decompression table in Air Decompression, a chapter in the United States Navy Diving Manual.
The table provides a schedule for ascent that usually allows excess nitrogen to escape without causing harm. The computer calculates the decompression schedule for a safe return to the surface and indicates when decompression stops are needed. In addition to following a table or computer guidelines for ascent, many divers make a safety stop of a few minutes at about 15 feet 4. Following these procedures, however, does not eliminate the risk of decompression sickness.
A small number of cases of decompression sickness develop after no-stop dives. The persistence of decompression sickness may be because the published tables and computer programs do not completely account for the variation in risk factors among different divers or because some people fail to obey the recommendations of the tables or computer. Flying within 12 to 24 hours after diving common when vacationing increases the risk of decompression sickness. After several days of diving, a period of 12 to 24 hours for example, 15 hours at the surface is commonly recommended before flying or going to a higher altitude.
People who have completely recovered from mild decompression sickness should refrain from diving for at least 2 weeks. After serious decompression sickness, it is best to wait longer at least a month and be evaluated by a physician before diving again. People who have developed decompression sickness despite following dive table or computer recommendations should return to diving only after a thorough medical evaluation for underlying risk factors, such as a heart defect. Divers having only itching, skin mottling, and fatigue usually do not need to undergo recompression, but they should be kept under observation, because more serious problems may develop.
After recompression, pressure is reduced gradually, with designated pauses, allowing time for excess gases to leave the body harmlessly. Because symptoms may reappear or worsen over the first 24 hours, even people with only mild or transient pain or neurologic symptoms are treated. Recompression therapy may be beneficial for up to 48 hours or longer after diving and should be given even if reaching the nearest chamber requires significant travel. While awaiting transport and during transport, oxygen is administered with a close-fitting face mask, and fluids are given by mouth or intravenously.
Long delays in treatment increase the risk of permanent injury. The following English-language resources may be useful. Divers Alert Network : hour emergency hotline, Duke Dive Medicine : hour emergency consultation with a doctor, Merck and Co. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world.
The Manual was first published in as a service to the community. Learn more about our commitment to Global Medical Knowledge. This site complies with the HONcode standard for trustworthy health information: verify here. Common Health Topics. Scuba injuries may be mild. But in some cases, they can cause serious problems or even death. There are three kinds of injuries from pressure changes when diving: Barotrauma: Tissues near the air-filled spaces of your body—such as your ears, sinuses, dental roots, and lungs—can be damaged if your body can't equalize the pressure between it and the surrounding water.
This kind of injury is called barotrauma. As you descend, water pressure increases, and the volume of air in your body decreases. This can cause problems such as sinus pain or a ruptured eardrum. As you ascend, water pressure decreases, and the air in your lungs expands. This can make the air sacs in your lungs rupture and make it hard for you to breathe.
If air bubbles get into an artery, they can cause a blockage that affects your organs. The blockage is called an arterial gas embolism.
Depending on where the bubbles are, you could have a heart attack or a stroke. Decompression sickness: Often called "the bends," decompression sickness happens when a scuba diver ascends too quickly.
Divers breathe compressed air that contains nitrogen. At higher pressure under water, the nitrogen gas goes into the body's tissues. This doesn't cause a problem when a diver is down in the water. And if a diver rises to the surface decompresses at the right rate, the nitrogen can slowly and safely leave the body through the lungs. But if a diver rises too quickly, the nitrogen forms bubbles in the body.
This can cause tissue and nerve damage. In extreme cases, it can cause paralysis or death if the bubbles are in the brain. Nitrogen narcosis: Deep dives can cause so much nitrogen to build up in the brain that you can become confused and act as though you've been drinking alcohol.
You might make poor decisions, such as taking out your regulator because you think you can breathe underwater. Narcosis usually happens only on dives of more than feet. What are the symptoms?
Mild symptoms can include: Pain in your ears, sinuses, or teeth. Joint pain. Extreme fatigue. When the pressure is released by opening, the gas rapidly forms bubbles. The bubbles lead to a range of symptoms, which emerge soon after you surface. Pain is often the first indicator, Michael says, usually in the joints and muscles — and many divers mistake it for muscle fatigue. Other symptoms include unpleasant itchiness and skin rashes caused by bubbles in and under the skin, as well as headaches, dizziness and nausea.
More serious damage can be done to arteries. But the bubbles can rip off all the coating, then everything starts to stick, and the blood vessel can become leaky and stop working. In the most serious cases paralysis, brain damage, heart attacks and breathing difficulties can result. In these cases, the damage can cause tingling, numbness and unconsciousness. Damage to the brain can cause vision impairment, headaches, confusion and problems with balance and coordination. Cases that lead to strokes, seizures, paralysis and death are often due to arterial gas embolism: air bubbles that form in one place but get lodged in the heart, lung or brain.
The best way to avoid DCS is to follow advice on rate of ascent. Failing that, treatment can come in the form of painkillers for mild cases, oxygen which helps speed up the elimination of nitrogen and the use of a hyperbaric or recompression chamber. These chambers expose sufferers to high pressure, causing nitrogen bubbles to redissolve and safely diffuse out of the tissues.
The experts stress that taking precautions is the best way to avoid disaster. The advent of dive computers, to complement dive tables, has been a big help in recent years, says Peter. Ensuring that you have enough gas to take the safety stops is a prerequisite — a dive to 18m, for example, requires a five-minute stop at 5m.
One final thing to avoid, Peter says, is flying within 24 hours. Travelling in aircraft that are not fully pressurised at altitude can cause nitrogen bubbles to form, even when there was no problem at ground level.
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