Decompression Illness: What Is It and What Is The Treatment? — DAN | Divers Alert Network — Medical Dive Article Decompression Illness: What Is It and What Is The Treatment? By Dr. E.D. Thalmann, DAN Assistant Medical Director With reports by Renée Duncan, editor, and Joel Dovenbarger, vice president, DAN Medical Services NOTE: This article was published in March/April 2004. Decompression illness, or DCI, is a term used to describe illness that results from a reduction in the ambient pressure surrounding a body. A good example is what happens to your body when you&#39re surfacing after a dive. DCI encompasses two diseases, decompression sickness (DCS) and arterial gas embolism (AGE). DCS is thought to result from bubbles growing in tissue and causing local damage, while AGE results from bubbles entering the lung circulation, traveling through the arteries and causing tissue damage at a distance by blocking blood flow at the small vessel level. Who Gets DCI? Decompression illness affects scuba divers, aviators, astronauts and compressed-air workers. It occurs in approximately 1,000 U.S. scuba divers each year.

Moreover, DCI hits randomly. The main risk factor for DCI is a reduction in ambient pressure, but there are other risk factors that will increase the chance of DCI occurring. These known risk factors are deep / long dives, cold water, hard exercise at depth, and rapid ascents. Rapid ascents are closely linked to the risk of AGE. Other factors thought to increase the risk of DCI but for which evidence is not conclusive are obesity, dehydration, hard exercise immediately after surfacing, and pulmonary disease. In addition, there seem to be individual risk factors that have not yet been identified. This is why some divers seem to get DCI more frequently than others although they are following the same dive profile. Since DCI is a random event, almost any dive profile can result in DCI, no matter how safe it seems. The reason is that the risk factors, both known and unknown, can influence the probability of DCI in myriad ways. Because of this, evaluation of a diver for possible decompression illness must be made on a case-by-case basis by evaluating the diver&#39s signs and symptoms and not just based on the dive profile.

Decompression Sickness Decompression sickness (DCS, also called the bends or caisson disease) is the result of inadequate decompression following exposure to increased pressure. In some cases, the disease is mild and not an immediate threat. In other cases, serious injury does occur; when this happens, the quicker treatment begins, the better the chance for a full recovery. During a dive, the body tissues absorb nitrogen from the breathing gas in proportion to the surrounding pressure. As long as the diver remains at pressure, the gas presents no problem. If the pressure is reduced too quickly, however, the nitrogen comes out of solution and forms bubbles in the tissues and bloodstream. This commonly occurs as a result of violating or approaching too closely the diving table limits, but it can also occur even when accepted guidelines have been followed. Bubbles forming in or near joints are the presumed cause of the joint pain of a classical "bend." When high levels of bubbles occur, complex reactions can take place in the body, usually in the spinal cord or brain. Numbness, paralysis and disorders of higher cerebral function may result.

If great amounts of decompression are missed and large numbers of bubbles enter the venous bloodstream, congestive symptoms in the lung and circulatory shock can then occur. Symptoms of DCS - Skin may show a blotchy rash - Paralysis, muscle weakness - Confusion, personality changes, bizarre behavior - Amnesia, tremors - Coughing up bloody, frothy sputum - Collapse or unconsciousness Note: Symptoms and signs usually appear within 15 minutes to 12 hours after surfacing; but in severe cases, symptoms may appear before surfacing or immediately afterwards. Delayed occurrence of symptoms is rare, but it does occur, especially if air travel follows diving. Denial and Recognition The most common manifestations of DCS are joint pain and numbness or tingling. Next most common are muscular weakness and inability to empty a full bladder. Severe DCS is easy to identify because the signs and symptoms are obvious. However, most DCS manifests subtly with a minor joint ache or a paresthesia (an abnormal sensation like burning, tingling or ticking) in an extremity. In many cases these symptoms are ascribed to another cause such as overexertion, heavy lifting or even a tight wetsuit.

This delays seeking help and is why it is often noted that the first symptom of DCS is denial. Sometimes these symptoms remain mild and go away by themselves, but many times they increase in severity until it is obvious to you that something is wrong and that you need help. What happens if you don&#39t seek treatment? In severe DCS, a permanent residual handicap may result: this can be a bladder dysfunction, sexual dysfunction or muscular weakness, to name a few. In some cases of neurological DCS, there mat be permanent damage to the spinal cord, which may or may not cause symptoms. However, this type of damage may decrease the likelihood of recovery from a subsequent bout of DCS. Untreated joint pains that subside are thought to cause small areas of bone damage called osteonecrosis. Usually this will not cause symptoms unless there are many bouts of untreated DCS. If this happens, however, there may be enough damage to cause the bone to become brittle or for joints to collapse or become arthritic. Prevention of DCS Recreational divers should dive conservatively, whether they are using dive tables or computers.

Experienced divers often select a table depth (versus actual depth) of 10 feet (3 meters) deeper than called for by standard procedure. This practice is highly recommended for all divers, especially when diving in cold water or when diving under strenuous conditions. Computer divers should be cautious in approaching no-decompression limits, especially when diving deeper than 100 feet (30 meters). Avoiding the risk factors noted above (deep / long dives, exercise at depth or after a dive) will decrease the chance of DCS occurring. Exposure to altitude or flying too soon after a dive can also increase the risk of decompression sickness. DAN has recently published guidelines for flying after diving.* Arterial Gas Embolism If a diver surfaces without exhaling, air trapped in the lungs expands with ascent and may rupture lung tissue - called pulmonary barotrauma - which releases gas bubbles into the arterial circulation. This distributes them to body tissues in proportion to the blood flow. Since the brain receives the highest proportion of blood flow, it is the main target organ where bubbles may interrupt circulation if they become lodged in small arteries. This is arterial gas embolism, or AGE, considered the more serious form of DCI.

In some cases the diver may have made a panicked ascent, or he may have held his breath during ascent. However, AGE can occur even if ascent appeared completely normal, and pulmonary disease such as obstructive lung disease may increase the risk of AGE. The most dramatic presentation of air embolism is the diver who surfaces unconscious and remains so, or the diver who loses consciousness within 10 minutes of surfacing. In these cases, a true medical emergency exists, and rapid evacuation to a treatment facility is paramount. On the other hand, air embolism may cause less spectacular symptoms of neurological dysfunction, such as sensations of tingling or numbness, a sensation of weakness without obvious paralysis, or complaints of difficulty in thinking without obvious confusion in individuals who are awake and easily aroused. In these cases, there is time for a more thorough evaluation by a diving medical specialist to rule out other causes of symptoms. Like DCS, mild symptoms may be ascribed to causes other than the dive, which only delays treatment. Sometimes symptoms may resolve spontaneously and the diver will not seek treatment.

The consequences of this are similar to untreated DCS: residual damage to the brain may occur, making it more likely there will be residual symptoms after a future bout of AGE, even if the later bout is treated. Symptoms of AGE - Cessation of breathing - Death Currently cerebral gas embolism is responsible for approximately 10 percent of all DCI cases annually. AGE has decreased significantly over the past decade, however, moving from 18 percent of all cases in the late 1980s and early 1990s to much lower numbers. By 1997, the fraction had fallen to 7-8 percent. In 2001, AGE was still cited in 7-8 percent but by 2002 it had fallen to 6.6 percent of the total diving population reporting DCI. It has been speculated that one of the reasons for this decrease is the advent of dive computers, which help chart the rate of ascent, thus reminding divers to slow down. Prevention of AGE Always relax and breathe normally during ascent.

Lung conditions such as asthma, infections, cysts, tumors, scar tissue from surgery or obstructive lung disease may predispose a diver to air embolism. If you have any of these conditions, it warrants an evaluation by a physician knowledgeable in diving medicine. Treatment - Call DAN! The treatment for DCI is recompression. However, the early management of air embolism and decompression sickness is the same. Although a diver with severe DCS or an air embolism requires urgent recompression for definitive treatment, it is essential that he be stabilized at the nearest medical facility before transportation to a chamber. Early oxygen first aid is important and may reduce symptoms substantially, but this should not change the treatment plan. Symptoms of air embolism and serious decompression sickness often clear after initial oxygen breathing, but they may reappear later. Because of this, always contact DAN or a dive physician in cases of suspected DCI - even if the symptoms and signs appear to have resolved. Treatment involves compression to a treatment depth, usually 60 feet, and breathing high oxygen fraction gases at an oxygen partial pressure of between 2.8 ata (atmospheres) and 3.0 ata.

Delays in seeking treatment have a higher risk of residual symptoms; over time, the initially reversible damage may become permanent. After a delay of 24 hours or more, treatment may become ineffective and symptoms may not respond to treatment. Even if there has been a delay, however, consult a diving medical specialist before drawing any conclusions about possible treatment effectiveness. In some cases, there may be residual symptoms after a treatment. Soreness in and around a joint that was affected by DCS is common and usually resolves in a few hours. If the DCI was severe, significant residual neurological dysfunction may be present, even after the most aggressive treatment. In these cases, there may be follow-up treatments, along with physical therapy. The good news is that the usual outcome is eventual complete relief from all symptoms, provided treatment was begun promptly. Care Of The Diver With Decompression Illness I. Determine the Urgency of the Injury Make an initial evaluation at the dive site. Suspect decompression illness if any of the signs or symptoms previously described occur within 24 hours of surfacing from a dive. The initial state of the affected diver will determine the order and urgency of the actions taken. Based on a classification used by the U.S.

Navy, the diver can be placed in one of three case categories: - emergency - timely Category A - Emergency Cases Of DCI Symptoms are severe and appear rapidly, within an hour or so of surfacing. Unconsciousness may occur. Symptoms may be progressing, and the diver is obviously ill. The diver may be profoundly dizzy, have trouble breathing or have major abnormalities in consciousness. Obvious neurological injury is seen in altered consciousness, abnormal gait or weakness. These divers are obviously very sick, and a true medical emergency exists. If necessary (e.g., if the diver is unconscious), begin CPR and take immediate action to have the diver evacuated. Check for foreign bodies in the airway. If ventilatory or cardiac resuscitation is required, the injured diver must be supine (lying on the back). Vomiting in this position, however, is extremely dangerous; if it occurs, quickly turn the diver to the side until the airway is cleared and resuscitation can resume in the supine position. If available, use supplemental oxygen while administering breaths to increase the percentage of oxygen received by the injured diver.

Even if CPR is successful and the diver regains consciousness, 100 percent oxygen should be provided and continued until the diver arrives at a medical facility. If Trained Healthcare Personnel Are Available . . . ... then an intravenous (IV) infusion using isotonic fluids without dextrose should be started. An initial rapid infusion of 1 liter over 30 minutes should begin to correct any dehydration and reduce hemoconcentration. Once this is accomplished, then the rate of administration should be reduced to a 100-175 cc / hour maintenance rate. Additional 1-liter boluses may be required to further correct dehydration and maintain blood pressure but should only be given by trained healthcare personnel capable of weighing the need for further fluid with possible complications. These would include fluid overload problems and discomfort from urinary retention in divers with abnormal bladder function due to spinal cord decompression sickness. If trained personnel are available, a urinary catheter should be placed in all unconscious divers and in those who cannot urinate. Call DAN After stabilization and arrangements for evacuation, contact DAN for advice on the nearest chamber location. DAN medical experts can get in touch with the receiving facility to assist in diagnosis and, if necessary, treatment.

Do this even if the diver appears to be improving on oxygen. While awaiting evacuation, take as detailed a history as possible and try to evaluate and record the diver&#39s neurological status. These facts are useful to the receiving medical facility. If air evacuation is used, cabin pressure should be maintained near sea level and not exceed 800 feet / 244 meters unless aircraft safety is compromised. Place the diver in the lateral recumbent position, also known as the recovery position. This puts the person on one side (usually left) with head supported at a low angle and the upper leg bent at the knee. If vomiting occurs in this position, gravity will assist in keeping the airway clear. Category B - Urgent Cases Of DCI Here, the only obvious symptom is severe pain that is unchanging or has progressed slowly during the past few hours. The diver does not appear to be in distress except for the pain, and the neurological signs and symptoms are not obvious without a careful history and examination. Immediately place the injured diver on 100 percent oxygen and give fluids by mouth. Do not attempt to treat the pain with analgesics until advised to do so by medical personnel. Continue providing oxygen until arrival at the medical treatment facility.

Contact DAN or the nearest medical facility for advice on what sort of transport is necessary and where the diver should be evacuated to, even if symptoms improve or are relieved with oxygen. Emergency air transport may not be necessary in all cases. While awaiting evacuation, take as detailed a history as possible and try to evaluate and record the diver&#39s neurological status. This information will be useful to those at the receiving medical facility. If air evacuation is used, cabin pressure should be maintained near sea level and not exceed 800 feet unless aircraft safety is compromised. Category C - Timely Cases Of DCI Symptoms are either not obvious or have progressed slowly for several days. Usually the main signs or symptoms are vague complaints of pain or an abnormality of sensation; the diagnosis of DCI may be in question. Obtain as complete a diving history as possible and do a neurological evaluation. Then call DAN or the nearest medical facility for advice or go to the nearest medical facility, if nearby, for evaluation. II.

Get the Dive History If possible, obtain and document the following information for all suspected cases of DCI: - For 48 hours preceding the injury, get a description of all dives: depths / times, ascent rates, intervals between dives, breathing gases, problems or symptoms at any time before, during or after the dive; - Ask for symptom onset times and progression after the diver has surfaced from last dive; - Get a description of all first aid measures taken (including times and method of 100 percent oxygen delivery) and their effect on symptoms since the injury; - Record the results of the on-site neurological examination (described below); - Make a description of all joint or other musculoskeletal pain including: location, intensity and changes with movement or weight-bearing maneuvers; - Get a description and distribution of any rashes; and - Provide a description of any traumatic injuries before, during or after the dive. III. Conduct an On-Site Neurological Examination Information regarding the injured diver&#39s neurological status will be useful to medical personnel in not only deciding the initial course of treatment but also in the effectiveness of treatment.

Examination of an injured diver&#39s central nervous system soon after an accident may provide valuable information to the physician responsible for treatment. The On-Site Neuro Exam is easy to learn and can be done by individuals with no medical experience. Perform as much of the examination as possible, but do not let it interfere with evacuation to a medical treatment facility. The examination is given on the DAN website and is also in the DAN Dive and Travel Medical Guide. IV. Get the Injured Diver to the Nearest Medical Facility and Call DAN Call for local EMS first; then call DAN. Depending on the severity of the injury (see above), take immediate care for the diver&#39s airway, breathing and circulation and contact local EMS. After making contact with EMS, then call DAN. Call the DAN Emergency Hotline Call +1-919-684-9111 to talk to an expert in diving medicine. You may call collect. DAN medical staff is on call 24 hours a day to handle diving emergencies. When You Call the DAN Emergency Hotline: 1. Tell the operator you have a diving emergency.

The operator will either connect you directly with DAN or have someone call you back at the earliest possible moment. 2. The DAN staff member may make an immediate recommendation or call you back after making arrangements with a local physician or the DAN Regional Coordinator. DAN Regional Coordinators are familiar with chamber facilities in their area, and because they&#39re qualified in diving medicine, they make recommendations about treatment. 3. The DAN staff member or Regional Coordinator may ask you to wait by the phone while he / she makes arrangements. These plans may take 30 minutes or longer, as several phone calls may be required. This delay should not place the diver in any greater danger. However, if the situation is life-threatening, arrange to transport the diver immediately to the nearest local medical facility for immediate stabilization and assessment of his or her condition. Call the DAN Emergency Hotline (+1-919-684-9111) if you need evacuation assistance through DAN TravelAssist. A Perspective The above tries to paint an accurate picture of DCI and its consequences; you should not conclude, however, that recreational diving is likely to cause injury.

In fact, DCI is rare: researchers estimate between three and four cases of dive injuries reported for every 10,000 dives - approximately 1,000 cases per year. In addition the vast majority of the DCI cases are minor and treatment results in complete resolution with no impact on future diving activity. Like any sport, scuba diving does have injuries, and knowing how to recognize DCI will ensure that in the unlikely event it does occur, the outcome will almost always be favorable. DAN is available 24/7 to assist in getting treatment for any dive injury and has access to world-class experts in the diagnosis and treatment of DCI. Not many other sports can boast of that kind of immediate support. DAN is not resting on its laurels, though. We&#39re continuing to look for ways to reduce the number of diving accidents even further. Project Dive Exploration (PDE) is a study designed to do just this. This study trains observers to recognize DCI, and they then collect dive profile data and compile information on behavioral and health aspects. The principal goal of PDE is to establish a recreational dive database that will serve as resource research in dive safety.

To learn more about PDE, see Returning to Diving after DCI The U.S. Navy has set down rules for returning to diving after treatment. For pain-only DCI where there are no neurological symptoms, divers may begin diving two to seven days after treatment, depending on the treatment table used. If there are neurological symptoms, the diver may resume diving two to four weeks after treatment, depending on symptom severity. For very severe symptoms, the diver must be reevaluated three months after treatment and cleared by a Diving Medical Officer. The Navy&#39s guidelines are for professionals, where time off must be minimized so operations are not compromised. Guides For Sport Divers For recreational divers, where diving is not a livelihood, a more conservative approach is called for to further minimize the chance that a diving injury will recur. After pain-only DCI where there are no neurological symptoms, a minimum of two weeks without diving is recommended. If there are minor neurological symptoms, six weeks without diving is recommended. If there are severe neurological symptoms or any residual symptoms, no further diving is recommended. Even if symptoms were not severe and they resolved completely, a diver who has had multiple bouts of DCI must take special considerations.

If DCI is occurring where other divers on the same profile are DCI-free, the diver may have an increased susceptibility to DCI. In these cases, a Diving Medical Specialist must be consulted to determine if diving can be resumed safely. Remember, your good health needs to last as long as you do. ---- * See the January/February 2004 issue, "How Long to Wait? DAN Discusses Provisional Guidelines for Flying After Diving," by Richard D. Vann, Ph.D., vice president, DAN Research. ---- © DAN — Alert Diver March/April 2004 NOTE: This article has been updated to reflect the new DAN Emergency Hotline number: +1-919-684-9111. Scuba Diving: Barotrauma and Decompression Sickness Scuba Diving: Barotrauma and Decompression Sickness Outlook Barotrauma/Decompression Sickness Overview Barotrauma refers to medical problems that arise from the pressure differences between areas of the body and the environment and is a particular concern for scuba divers. Certain laws of physics apply to this topic.

Boyle's law states that the product of the multiplication of pressure and volume remains a constant. As the pressure increases, the volume decreases and vice versa. As you dive deeper when scuba diving, pressure increases and this volume change in gas -filled spaces and organs within your body accounts for the distortion and damage to surrounding tissues. Decompression sickness, or "the bends ," is related more to Henry's Law, which states that more gas will be dissolved in a liquid when the gas is pressurized. Because of the water pressure, body tissue absorbs nitrogen gas faster as a diver descends than when ascending to the surface. However, if a diver ascends too quickly, nitrogen gas bubbles will form in body tissue rather than being exhaled. The nitrogen bubbles cause severe pain . External ear squeeze occurs when your ear canal is blocked by something such as earplugs or earwax . As the water pressure increases while you descend, the air pocket between the obstruction and the tympanic membrane (eardrum) shrinks. This can damage the tissue in the ear canal, usually your eardrum. Middle ear squeeze occurs when you cannot equalize the pressure in your middle ear .

The eustachian tube is a small canal that connects the middle ear to the back part of the nasal cavities and allows pressure to equalize. When there is a problem with the tube, the middle ear volume decreases and pulls the eardrum inward, creating damage and pain . You can try certain maneuvers, called Valsalva maneuvers, such as yawning or trying to blow with your nose and mouth closed, to open the tube and equalize the pressure. Inner ear barotrauma occurs from the sudden development of pressure differences between the middle and inner ear. This can result from an overly forceful Valsalva maneuver or a very rapid descent. The result is usually ringing in the ear , dizziness , and deafness. This injury is less common than a middle ear squeeze . Less common types of barotrauma include the following. All involve air trapped in an enclosed area where pressure cannot equalize during descent causing a vacuum effect where it occurs. Sinus squeeze: When air becomes trapped in the sinuses because of congestion or cold symptoms, a sinus squeeze can occur. Face mask squeeze: This occurs if you do not exhale through your nose into the dive mask while descending (equalizing).

Suit squeeze: A dry diving suit tightly encloses an area of skin. Lung squeeze: This occurs when you are free-diving, but very few divers can hold their breath to depths that cause this injury to occur. Tooth squeeze: This occurs during an ascent while scuba diving and air becomes trapped in a filling or cavity. Gastric squeeze (aerogastralgia): This occurs when gas swallowed during diving expands during ascent. This happens more often with novice divers and causes temporary pain but rarely significant damage. Barotrauma can occur during ascent also. A reverse squeeze occurs in the middle ear or sinus when a diver has an upper respiratory infection (cold) and has used nasal spray to open the breathing passages. As the spray wears off during diving, tissues swell and cause obstruction, resulting in a pressure difference and damage. During "bounce diving" the eustachian tube may become inflamed and lead to a middle ear squeeze. Pulmonary barotrauma (pulmonary overpressurization syndrome, POPS, or burst lung) can occur if the diver fails to expel air from the lungs during ascent.

As the diver rises, the volume of the gas in the lung expands and can cause damage if the excess is not exhaled. Air embolism is the most serious and most feared consequence of diving. While scuba diving, gas bubbles can enter the circulatory system through small ruptured veins in the lungs. These bubbles expand during ascent, following Boyle's Law, and can pass through the heart to obstruct blood flow in the arteries of the brain or heart. This most commonly occurs when a diver ascends rapidly because of air shortage or panic. The diver then passes out, experiences a stroke , or has other nervous system complaints within minutes of surfacing. The brain is affected more than other organs because gas rises, and most divers are in a vertical position while ascending. Decompression sickness (DCS, "the bends") involves gases diffusing into the tissues and getting trapped there. The diver now has gas bubbles in places where there should be none. Nitrogen is the usual culprit. During descent and while on the bottom, the diver absorbs nitrogen into the tissues until they reach a pressure balance. When the diver ascends at the right rate, the gas diffuses from the tissues.

However, if the diver ascends too rapidly to allow diffusion, the nitrogen bubbles will expand in the tissues as pressure decreases. Different body parts can be affected, depending on where the bubbles are located. Medically Reviewed by a Doctor on 5/5/2016 Medical Author: Scuba Diving | What Are The Bends And How Do You Pre... Share When learning to scuba dive , there are a few things that everyone worries about. Whether it be finding the right diving equipment, going a safe dive spot in the UK, or just getting the right diving qualifications to dive, there are many different things to consider when getting in the water. The big thing most people worry about however, are the dreaded bends and whether they will happen to them. Scuba Diving For Beginners | Everything You Need To Know The bends, or decompression sickness, is widely known both inside diving culture and in general culture more widely, yet what it actually means eludes most people. Also known as Caisson disease, it is a condition that does not occur in freediving , but can happen when a diver is using a breathing regulator. The symptoms can effect just about any body area including joints, lung, heart, skin and brain.

Whether you’re starting to dive and wondering what the bends actually are, wanting to dive deeper and need information on how to avoid the bends, or just want to know how to treat them if they do happen, look no further – All of the information you could ever want on the dreaded bends is right here! Definition Of The Bends The bends are also called ‘Decompression Sickness’ and occur because of the release of gases in the body Photo: iStock Related Articles Dive Watches | What To Look For in a Good Diving Watch The bends are the process of dissolved gases (mainly nitrogen) that come out of solution in bubbles because of decompression in scuba divers or high altitude or aerospace events. They can affect any body area including joints, lung, heart, skin and brain. The popular description for the bends or decompression sickness was classified through it symptoms by F.C.

Golding in 1960 as: “Type I (‘simple’)” for symptoms involving only the skin, musculoskeletal system, or lymphatic system” “Type II (‘serious’)” for symptoms where other organs (such as the central nervous system) are involved.” Exposure to the bends when diving can be managed through proper decompression prevention and are becoming a lot less common than they have been in the past, however they can still be very serious when contracted. Computers and tablets are used by divers, to control ascent speed and avoid DCS (decompression sickness.) What Causes The Bends? The bends can happen to a diver of any experience level Photo: iStock The bends occurs in the body after scuba diving because of gases in the body releasing as bubbles on depressurisation. When we are living on dry land at sea level, the air around us has a pressure of 14.7 PSI (pounds per square inch), or one atmosphere. That is a “normal pressure” for our bodies. Water is heavy compared to air, it does not take much water to exert a lot of pressure.

One-inch by one-inch column of water 33 feet high exerts another 14.7 pounds per square inch than the same column of air. If you hold your breath and dive down 33 feet, your lungs contract in size by a factor of two because there is twice as much pressure around the air in your lungs, making them contract. When you rise back up, the air expands again and your lungs return to normal size. When you breathe from a scuba tank however, the air coming out of the tank has to have the same pressure as the pressure that the water is exerting. Therefore, when scuba diving, the air in your lungs at a 33-foot depth has twice the pressure of air on land and the pressure continues to double as the depth gets deeper. “If a diver stays under a low depth of water for a certain period of time, some amount of nitrogen from the air will dissolve inside them” Imagine a carbonated drink, Carbonation in liquid is made through high-pressure gases in the air coming in contact with water and dissolving. When you release the pressure in a bottle of carbonated liquid, the dissolved gas quickly rises as bubbles.

If a diver stays under a low depth of water for a certain period of time when diving , some amount of nitrogen from the air will dissolve inside them, much like the gas in carbonated drinks. If they swim to the surface quickly, the dissolves gasses inside their body will react in much the same way as those inside a carbonated drink and come to surface in bubbles. This occurrence in a human body is called decompression sickness and can cause many problems, at very worst it can be fatal to a diver. Related Articles What Are The Symptoms Of The Bends? The bends can attack any part of the human body Photo: iStock The symptoms of the bends can range from mild to excruciating and require different levels of treatment, depending on the individual. If an individual shows any of these symptoms when diving, provide them with an oxygen mask as soon as possible and call for a medical professional. Muscoskeletar -Localized deep pain and pain in the joints. Sometimes a dull ache, can be excruciating. Skin– Itching around the face, neck, and upper body. Sometimes skin can look marbled or swollen. Fatigue – A feeling of extreme tiredness.

The Chokes -Dry cough, chest pain, trouble beathing and shortness of breath. The Staggers – Loss of balance and hearing, dizziness, vertigo, nausea and vomiting. How To Prevent The Bends A decompression schedule must be created for the ascent of a dive, to avoid the bends Photo: iStock To prevent decompression sickness, divers limit their ascent rate and carry out a decompression schedule as necessary, to stop the release of bubbles that cause damage to the body. To safely ascend from a deep scuba diving session, divers must remain at each particular depth until sufficient gas has been eliminated from the body, each of these is called a decompression stop. “If you have access to oxygen, a mask should be applied to the diver as soon as possible.” Decompression stops are carefully measured by divers both before and during a diving session, through decompression tables, decompression software and dive computers. These are commonly based upon a mathematical model of the body’s uptake and release of inert gas as pressure changes. Breathing mixtures containing much less inert gas during the decompression phase of the dive can help to shorten decompression time on ascent.

How To Treat The Bends If a diver shows symptoms of the bends, provide them with an oxygen mask as soon as is possible Photo: iStock A doctor should always be called for in the case of the bends, however there are a few things you can do yourself to treat the symptoms of the bends, until medical help arrives. Dry the diver and warm with blankets if their body temperature shows sings of dropping. Administer fluids to fight off dehydration, but do not give aspirin as it may mask symptoms. If you have access to oxygen, a mask should be applied to the diver as soon as possible. Call both the emergency services and the Divers Alert Network to locate the nearest hyperbaric chamber (100% oxygen delivered in a high-pressure chamber) and to get specialist advice. The diver will need to lie in a horizontal position when transported and in the case of air transport, the cabin must stay below 1,000 feet, or pressurized to sea level pressure. Use high-flow oxygen throughout transportation and up to the point where a hyperbaric chamber is available. The duration of treatment depends on the symptoms, the diver’s history and the type of recompression therapy on hand.

Decompression Sickness - Causes, Types, and Symptoms Causes, Types, and Symptoms Guest Authors Also known as The Bends and Caisson Disease, Decompression Sickness is an illness that can affect divers or other people (such as miners) who are in a situation that involves pressure rapidly decreasing around the body. DCS, as it is commonly know, is caused by a build up of nitrogen bubbles in the body. When we breathe, approximately 79 of the air we're breathing is nitrogen. As we descend in water, the pressure around our bodies increases, causing nitrogen to be absorbed into our body tissues. This is not actually harmful and it's quite possible for the body to continue to absorb nitrogen until it reaches a point called saturation, which is the point at which the pressure in the tissues equals the surrounding pressure. The problem arises when this pressure needs to be released. In order to release the nitrogen slowly from the body, a diver must ascend slowly and carry out decompression stops if necessary - this allows the nitrogen to slowly seep out of the body tissues and either immediately revert to being a gas or to become tiny harmless bubbles which will eventually become revert to gas. continue reading below our video LeBron vs. Michael: Who's Better?

This process is called "Off-gassing" and is normally carried out through the lungs. If a diver ascends too fast and the nitrogen escapes the body tissue too quickly it becomes bubbles in the body and this leads to Decompression Sickness. The bubbles must normally be on the arterial side of the circulatory system to be harmful - they are usually harmless on the venous side. There are several types of Decompression Sickness: Type I Decompression Sickness Type I Decompression Sickness is the least serious form of Decompression Sickness. It normally involves only pain in the body and is not immediately life threatening. It is important to note that symptoms of Type I Decompression Sickness may be warning signs of more serious problems. This is when the nitrogen bubbles come out of solution in skin capillaries . This normally results in a red rash, often on the shoulders and chest. Joint and Limb Pain Decompression Sickness This type is characterized by aching in the joints. It is not known exactly what causes the pain as bubbles in the joint would not have this effect. The common theory is that it is caused by the bubbles aggravating bone marrow, tendons, and joints. The pain can be in one place or it can move around the joint.

It is unusual for bisymmetrical symptoms to occur. Type II Decompression Sickness Type II Decompression Sickness is the most serious and can be immediately life-threatening. The main effect is on the nervous system. Neurological Decompression Sickness When nitrogen bubbles affect the nervous system they can cause problems throughout the body. This type of Decompression Sickness normally shows as tingling, numbness, respiratory problems, and unconsciousness. Symptoms can spread quickly and if left untreated can lead to paralysis or even death. Pulmonary Decompression Sickness This is a rare form of Decompression Sickness that occurs when bubbles form in lung capillaries. Fortunately, the majority of the time bubbles dissolve naturally through the lungs. However, it is possible for them to interrupt blood flow to the lungs which can lead to serious and life-threatening respiratory and heart problems. Cerebral Decompression Sickness It is possible for bubbles that make their way into the arterial blood stream to move to the brain and to cause an arterial gas embolism . This is extremely dangerous and can be identified by symptoms such as blurred vision, headaches, confusion, and unconsciousness.

Other Forms of Decompression Sickness Extreme tiredness is very common in cases of Decompression Sickness and can sometimes be the only symptom of Decompression Sickness present. It is not know what causes this but you should be aware that extreme fatigue could be a sign of more serious problems. It is also possible for Decompression Sickness to occur in the inner-ear. This is caused by bubbles forming in the cochlea 's perilymph during decompression. The result can be hearing loss, dizziness, ringing of the ears, and vertigo . Symptoms Decompression Sickness can manifest itself in many different ways and has many different symptoms, but the most common symptoms are: Extreme Fatigue Decompression Sickness - Maldives Blog | Maldives Blog Decompression Sickness Decompression Sickness Scuba Diver in Water Scuba divers are commonly susceptible to Decompression sickness, or as it is more commonly known, “The Bends.” This sickness occurs in people who find themselves in a situation that involves a rapid decrease in pressure around the body. Causes of Decompression Sickness Decompression Sickness, or DCS for short, occurs when nitrogen bubbles build up in the body.

During normal breathing, about 79% of the air we breathe is nitrogen; but as we descend in water, our being submerged in the water causes an increase in pressure, and nitrogen is absorbed into our body tissue. Decompression Sickness is not instantly detrimental and it is possible for the body to continue absorbing nitrogen until the point of saturation – when the pressure in our tissue equals the outside pressure. The problem occurs when pressure needs to be released. To counter the sudden change of pressure, scuba divers must ascend from deep water at a slow pace; taking pauses – or safety stops – if necessary, so that the nitrogen can slowly, steadily and safely leak out from the bodily tissue. Decompression Sickness occurs when the ascent is performed too quickly, as the nitrogen escapes from the body too quickly and forms bubbles within the bodily tissue. Normally, any bubbles within the tissue must be on the arterial side of the circulatory system in order to be harmful, while they are generally harmless when on the venous side of the tissue.

Types of Decompression Sickness There are several types of Decompression Sickness (DCS), the first of which is characterised by pain but is not immediately life-threatening, and could be a mere warning sign of more serious problems. More serious types of Decompression Sickness include Cutaneous Decompression Sickness, where nitrogen bubbles come out of through skin capillaries, and Joint and Limb Pain Decompression Sickness. The second type is more serious and can be fatal as it affects the nervous system. Neurological, Pulmonary, and Cerebral Decompression Sickness are examples of DCS where the nitrogen bubbles affect the nervous system, lungs, or brain, respectively. Some common symptoms of both types include extreme fatigue, joint and limb pain, tingling, numbness, dizziness, blurred vision, and headaches. Treatment of Decompression Sickness Treatment of Decompression Sickness is generally administered on the scene, and consists of oxygen therapy and basic first aid. Recompression treatment in a hyperbaric chamber must immediately follow, and the slightest delay in beginning recompression treatment can be the biggest single cause of residual effects. The best treatment for Decompression Sickness is prevention, so follow these tips.

Always ascend slowly and safely from every dive, don’t push your limits, perform all required decompression stops and keep physically fit and within a healthy weight range. Decompression Sickness Treatment in the Maldives There are several hyperbaric chambers in the Maldives , including: Bandos Medical Clinic and Hyperbaric Centre, Bandos Island Resort, North Male Atoll, Telephone + 960 440 088 Kuramathi Medical Centre, Kuramathi Island Resort, Alifu Alifu Atoll , Telephone + 960 773 485 Kandoludhoo Divers Rescue, Kandoludhoo Island Resort, South Ari Atoll, Telephone + 960 773 485 NOAA Ocean Explorer: Technology: Diving: Technical Diving Technology | Diving | Technical Diving Technical Diving Technical diving is a term used to describe all diving methods that exceed the limits imposed on depth and/or immersion time for recreational scuba diving. Technical diving often involves the use of special gas mixtures (rather than compressed air) for breathing.

The type of gas mixture used is determined either by the maximum depth planned for the dive or by the length of time that the diver intends to spend underwater. While the recommended maximum depth for conventional scuba diving is 130 feet, technical divers may work in the range of 170 feet to 350 feet, sometimes even deeper. Technical diving almost always requires one or more mandatory decompression "stops" upon ascent, during which the diver may change breathing gas mixes at least once. Decompression stops are necessary to allow gases that have accumulated in the diver's tissues (primarily nitrogen) to be released in a slow and controlled manner. If an individual exceeds the limits of time and/or depth for recreational diving, and/or ascends too quickly, large bubbles can form in the tissues, joints, and bloodstream. The formation of these bubbles leads to an extremely painful condition known as Decompression Sickness (DCS), more commonly known as the "bends," which can cause paralysis and even death. Nitrox People have used compressed air as their breathing medium since the advent of diving in the 1950s. Its main advantage is that it is readily available and relatively inexpensive to compress into cylinders.

Nevertheless, air is not the "ideal" breathing mixture for diving. With a concentration of approximately 79 percent nitrogen, compressed air poses two potential problems for all divers: susceptibility to nitrogen narcosis (a condition resembling alcoholic intoxication) at deeper depths; and decompression sickness (DCS). Both of these can prove fatal to a diver. In an effort to reduce the ill effects of nitrogen on divers, nitrox was developed. Nitrox is a generic term that can be used to describe any gaseous mixture of nitrogen and oxygen. In the context of technical diving, nitox is a mixture containing more oxygen than air. The two most commonly used nitrogen-oxygen mixtures contain 32 percent and 36 percent oxygen by volume. This differs significantly from compressed air, which contains approximately 21 percent oxygen by volume. While an increase of 12 to 16 percent oxygen by volume may not seem drastic, it allows divers to significantly extend their bottom time, and decreases their risk of developing DCS. While diving with nitrox has definite benefits, it also has clearly associated risks. The major hazard is oxygen toxicity.

This comes about when oxygen is inhaled in high concentrations for an extended period of time; this occurs primarily when a diver exceeds the recreational limits for depth. Under these circumstances, a diver can experience an epileptic-like seizure, which may lead to drowning. Due to this potentially fatal hazard, divers using nitrox must adhere to special dive tables. These tables list the maximum safe amount of time that a diver can stay underwater at a certain depth. Mixed-Gas Diving The term "mixed-gas diving" refers to any activity in which the diver breathes a mixture other than air or nitrox. The main incentive to dive with "non-air" gas mixtures is to avoid nitrogen narcosis. Mixed-gas diving can also be beneficial in improving decompression and avoiding oxygen toxicity. Mixed-gas diving operations require detailed planning, sophisticated equipment, and, at times, extensive support personnel and facilities. The fact that such dives are often conducted at great depths and for extended periods of time increases the risks associated with them. It is extremely important for the breathing mixture to be properly identified, because breathing the wrong mix can lead to a fatal accident. One type of mixed gas diving involves the use of heliox.

This (79 percent helium and 21 percent oxygen) mixture is often used for very deep diving. Unlike nitrogen, helium is not known to have an intoxicating effect at any depth; it has a lower density than nitrogen, making it easier to breathe; and in cases of extended submersion, it improves decompression. Still, heliox has its drawbacks. It is expensive, has a limited availability, and its thermal conductivity is six times greater than that of nitrogen. This means that a diver breathing heliox will lose body heat six times faster than someone breathing compressed air or nitrox, making them susceptible to hypothermia. To prevent this, divers often wear special suits filled with hot water that is pumped down from the surface. Heating the heliox before the diver inhales it is another strategy used to combat hypothermia. Either of these procedures require specialized equipment and highly trained personnel. Surface-supplied Diving Surface-supplied diving (SSD) is an alternative to self-contained equipment. This method consists of lowering divers into the water on a support platform, or stage, and supplying them with breathing gas (air or another gas mixture) through a flexible hose attached to a diving helmet.

Since the diver does not need to be concerned with a limited supply of breathing gas, SSD gives divers the flexibility they need to perform a variety of underwater tasks. The diver's helmet is connected to an "umbilical" that supplies breathing gas, two-way communications, a depth measurement tube and, optionally, hot water to warm the dive suit. In many cases, a camera and lights are mounted on the diver's helmet. Video from the diver's cameras, as well as audio communication, allow a dive supervisor to monitor activity throughout the dive, and provide recommendations if any difficulties arise. SSD is particularly effective on deep or extended operations when divers are working in a relatively restricted area. Surface-supplied diving provides several advantages over scuba. These include a direct physical link between the diver and the surface; a continual, unlimited supply of breathing gas; a means of controlling the diver's depth and location; and a means of providing video and audio links to the surface. Surface-supplied diving does, however, have disadvantages.

Among them, a diver's mobility and range are limited by the length of the umbilical; in strong currents, the pull on the umbilical can be severe; divers must walk along the bottom on weighted boots, and are unable to swim effectively; and SSD operations require a large support crew and a great deal of equipment. Scuba Diving: Barotrauma and Decompression Sickness Causes, Symptoms, Treatment - Barotrauma/Decompression Sickness Symptoms - eMedicineHealth Patient Comments Share Your Story You should consider the signs and symptoms of diving injuries with regard to your overall dive plan, including what part of the dive you were performing when the problems occurred. The history of the dive is very important to medical personnel and should always be included when assistance is required. Barotrauma such as squeezes will commonly occur during descent, and the symptoms will frequently prevent a diver from reaching the desired depth. You will notice symptoms of aerogastralgia, pulmonary barotrauma, air embolism, and decompression sickness both during and after ascent.

The following are symptoms for specific pressure problems: External ear squeeze: Pain in your ear canal and blood from your ear Middle ear squeeze: Ear fullness, pain, eardrum rupture, disorientation, nausea , and vomiting Inner ear barotrauma: Feeling that your ear is full, nausea, vomiting, ringing in the ear, dizziness, and hearing loss Sinus squeeze: Sinus pressure, pain, or nasal bleeding Face mask squeeze: "Bloodshot" eyes and redness or bruising of the face under the mask Lung squeeze: Chest pain , cough , bloody cough , and shortness of breath Aerogastralgia (gastric squeeze): Abdominal fullness, colicky pain (severe pain with fluctuating severity), belching, and flatulence (gas expelled through the anus). Pulmonary barotrauma: Hoarseness , neck fullness, and chest pain several hours after diving. Shortness of breath, painful swallowing, and loss of consciousness also may occur. Air embolism: Sudden loss of consciousness within 10 minutes of surfacing. Other symptoms include paralysis, numbness, blindness, deafness, dizziness, seizures , confusion, or difficulty speaking.

The paralysis and numbness can involve several different parts of the body at the same time. Decompression sickness: Rashes, itching, or bubbles under your skin Lymphatic obstruction which can cause localized swelling Musculoskeletal symptoms include joint pain that worsens with movement and commonly involves the elbows and shoulders Nervous system after-effects include paralysis, sensory disturbances, and bladder problems, usually the inability to urinate . Pulmonary symptoms include chest pain, cough, and shortness of breath. Symptoms usually appear within 1 hour of surfacing but can be delayed up to 6 hours. In rare instances symptoms may not appear until 48 hours after the dive. Flying in a commercial aircraft after diving may cause "the bends" to develop in the airplane because the cabin pressure is less than sea level pressure. Medically Reviewed by a Doctor on 5/5/2016 Medical Author:

Question: Among scuba divers, what is decompression sickness commonly known as?
Answer: The Bends