What are the main health risks associated with scuba diving. How can divers prevent decompression sickness and other diving-related injuries. What precautions should be taken when flying after diving. How to recognize and respond to diving emergencies.

Decompression Illness: The Silent Threat Beneath the Waves

Decompression illness encompasses two main conditions that can affect scuba divers: arterial gas embolism (AGE) and decompression sickness (DCS), commonly known as “the bends.” Both conditions are caused by the formation of gas bubbles in the body due to changes in pressure during ascent.

Arterial Gas Embolism: A Rapid-Onset Emergency

AGE occurs when gas bubbles enter the arterial blood through ruptured pulmonary vessels. These bubbles can travel to various parts of the body, including the heart and brain, causing serious complications. How quickly can AGE manifest? Symptoms can appear within minutes of surfacing, making it a true diving emergency.

• Suspect AGE if a diver loses consciousness within 10 minutes of surfacing
• Immediate administration of high-concentration oxygen is crucial
• Rapid evacuation to a hyperbaric facility is necessary, even if symptoms appear to improve

Decompression Sickness: The Pressure Problem

DCS, or “the bends,” results from the formation of nitrogen bubbles in tissues and blood as a diver ascends. Why does this happen? During a dive, the body absorbs excess nitrogen under pressure. If the ascent is too rapid, this nitrogen can form bubbles, leading to various symptoms.

• Symptoms can range from joint pain to neurological issues
• Risk increases with depth, duration, and multiple dives
• Proper ascent rates and safety stops are crucial for prevention

Beyond the Bends: Other Diving-Related Health Concerns

While decompression illness is a primary concern for divers, several other conditions can pose significant risks underwater. Understanding these potential hazards is essential for maintaining safety during scuba adventures.

Drowning: The Ever-Present Danger

Any incapacitation underwater can lead to drowning, making it a constant risk for divers. How can divers minimize this risk? Proper training, equipment maintenance, and diving within one’s limits are crucial preventive measures.

Marine Life Encounters: Beauty and Danger

The ocean teems with fascinating creatures, but some can pose threats to divers. What are the most common marine life injuries? Most incidents result from chance encounters or defensive actions by marine animals. Wounds may involve bacterial contamination, foreign bodies, bleeding, and occasionally venom.

Immersion Pulmonary Edema: When Water Pressure Affects Breathing

Immersion pulmonary edema (IPE) occurs when fluid shifts into the lungs due to the effects of water pressure on the body. Who is at higher risk for IPE? Factors such as age, overhydration, overexertion, and certain cardiac conditions can increase susceptibility.

• Symptoms include chest pain, difficulty breathing, and coughing up frothy sputum
• Can occur during descent or at depth
• Requires medical evaluation to rule out underlying cardiac issues

The Mind-Altering Effects of Depth: Nitrogen Narcosis and Oxygen Toxicity

As divers descend to greater depths, they face unique physiological challenges that can affect their mental state and decision-making abilities. Understanding these phenomena is crucial for safe deep diving.

Nitrogen Narcosis: The Rapture of the Deep

Nitrogen narcosis, often called “the rapture of the deep,” is a condition that affects divers at depths typically beyond 100 feet (30 meters). How does nitrogen narcosis manifest? The increased partial pressure of nitrogen in breathing gas at depth can cause impaired judgment, euphoria, and altered perception.

• Effects are similar to alcohol intoxication
• Symptoms clear rapidly upon ascent
• Can be life-threatening if it impairs a diver’s ability to make safe decisions

Oxygen Toxicity: Too Much of a Good Thing

While oxygen is essential for life, breathing it under high pressure can be dangerous. At what point does oxygen become toxic? In recreational diving with compressed air, oxygen toxicity is not typically a concern within normal depth limits. However, technical divers using enriched air mixtures must be aware of this risk.

• Can cause seizures at high partial pressures of oxygen
• More common in technical diving with enriched air mixtures
• Proper gas management and depth limits are crucial for prevention

The Air Travel Dilemma: Flying After Diving

The relationship between scuba diving and air travel is complex, with potential risks arising from changes in atmospheric pressure. Understanding these risks is crucial for divers planning to fly after their underwater adventures.

Why is Flying After Diving Risky?

Flying after diving increases the risk of developing decompression sickness. Why does this happen? Aircraft cabins are pressurized to altitudes between 6,000 and 8,000 feet (1,830-2,440 meters) above sea level. This decrease in pressure can cause residual nitrogen in a diver’s tissues to form bubbles, potentially leading to DCS.

Recommended Surface Intervals Before Flying

To minimize the risk of DCS, divers should adhere to specific guidelines regarding the time between their last dive and flying. What are these recommended surface intervals?

• At least 12 hours after a single no-decompression dive
• Minimum 18 hours after multiple dives or multiple days of diving
• 24-48 hours after dives requiring decompression stops

It’s important to note that these intervals reduce but do not eliminate the risk of DCS. Longer surface intervals provide an additional safety margin.

Diving After Flying: A Different Consideration

While there are no specific guidelines for diving after flying, divers should consider the effects of travel on their mental and physical readiness. How long should one wait before diving after a flight? It’s advisable to allow sufficient time to acclimate to the new location, recover from jet lag, and ensure proper hydration before embarking on a dive.

Preventive Measures: Diving Safely and Responsibly

Prevention is key when it comes to diving-related injuries and illnesses. By following best practices and understanding the risks, divers can significantly reduce their chances of experiencing adverse events.

Conservative Diving Practices

How can divers minimize their risk of decompression illness? Diving conservatively within the no-decompression limits of dive tables or computers is crucial. This approach provides a safety margin and reduces the likelihood of bubble formation.

• Follow recommended ascent rates (typically 30 feet or 9 meters per minute)
• Perform safety stops at 15-20 feet (4.5-6 meters) for 3-5 minutes, even on no-decompression dives
• Use dive computers to track nitrogen loading across multiple dives

Proper Training and Equipment Maintenance

Why is ongoing education important for divers? The field of diving medicine and safety is constantly evolving. Staying current with the latest knowledge and techniques can help divers make informed decisions and respond appropriately to emergencies.

• Regularly update diving skills and knowledge through continuing education
• Maintain and service diving equipment according to manufacturer recommendations
• Conduct thorough pre-dive equipment checks

Physical Fitness and Health Considerations

Maintaining good physical health is essential for safe diving. What health factors should divers consider? Cardiovascular fitness, proper hydration, and awareness of any underlying medical conditions are crucial aspects of dive preparation.

• Undergo regular medical check-ups to ensure fitness to dive
• Stay well-hydrated before, during, and after diving
• Avoid alcohol consumption before diving and limit it afterward
• Be aware of how certain medications may affect diving safety

Emergency Response: Recognizing and Reacting to Diving Incidents

Despite preventive measures, diving emergencies can still occur. Quick recognition and appropriate response are critical for positive outcomes in these situations.

Signs and Symptoms of Decompression Illness

How can divers recognize potential decompression illness? Symptoms can vary widely but may include:

• Joint pain or muscle aches
• Fatigue or weakness
• Skin rashes or itching
• Numbness or tingling sensations
• Dizziness or vertigo
• Difficulty breathing
• Visual or auditory disturbances
• Paralysis or unconsciousness (in severe cases)

Immediate Actions for Suspected Diving Injuries

What should be done if a diver shows signs of decompression illness or other diving-related injuries?

1. Provide high-concentration oxygen (100% if possible) immediately
2. Assess and maintain the ABCs (Airway, Breathing, Circulation)
3. Keep the diver lying flat and encourage fluid intake if conscious
4. Contact emergency services and the nearest hyperbaric treatment facility
5. Gather and record dive profile information for medical personnel

The Importance of Dive Insurance and Emergency Planning

Why is dive insurance crucial for scuba enthusiasts? Diving accidents can occur in remote locations, and evacuation to specialized treatment facilities can be extremely costly. Proper insurance coverage can provide peace of mind and ensure prompt access to necessary care.

• Consider purchasing specialized dive insurance that covers hyperbaric treatment
• Familiarize yourself with local emergency resources before diving in a new location
• Carry emergency contact information and insurance details on every dive

Advancing Dive Safety: Research and Technology

The field of dive medicine and safety is continually evolving, with new research and technologies emerging to enhance diver safety and understanding of physiological effects.

Innovations in Decompression Algorithms

How are decompression models improving? Researchers are developing more sophisticated algorithms that take into account individual factors and real-time data to provide personalized decompression guidance.

• Integration of biometric data into dive computers
• Machine learning applications for predicting decompression stress
• Development of more conservative decompression models for recreational diving

Advancements in Dive Equipment

What new technologies are enhancing dive safety? From improved breathing apparatus to sophisticated monitoring devices, equipment innovations are making diving safer and more accessible.

• Rebreather technology for extended dive times and reduced decompression obligation
• Enhanced dive computer functionality, including air integration and GPS
• Development of safer and more efficient decompression gases

Ongoing Research in Dive Physiology

How is our understanding of diving’s effects on the human body advancing? Continued research into the physiological impacts of diving is crucial for developing better prevention and treatment strategies.

• Studies on long-term effects of diving on cognitive function
• Investigation of genetic factors influencing susceptibility to decompression sickness
• Research into novel treatments for diving-related injuries

As our knowledge of diving physiology and safety continues to grow, so does our ability to enjoy the underwater world more safely and responsibly. By staying informed about the latest developments in dive medicine and technology, divers can make better decisions and minimize risks associated with this exhilarating activity.

Remember, while scuba diving offers unparalleled opportunities to explore the aquatic realm, it also comes with inherent risks. By understanding these risks, following safe diving practices, and staying prepared for emergencies, divers can maximize their enjoyment while minimizing the potential for adverse events. Whether you’re a novice or an experienced diver, ongoing education and a commitment to safety should always be at the forefront of your underwater adventures.

Scuba Diving: Decompression Illness & Other Dive-Related Injuries

Arterial Gas Embolism

Gas entering the arterial blood through ruptured pulmonary vessels can distribute bubbles into the body tissues, including the heart and brain, where they can disrupt circulation or damage vessel walls. The clinical presentation of arterial gas embolism (AGE) ranges from minimal neurologic findings to dramatic symptoms requiring urgent and aggressive treatment.

In general, suspect AGE in any scuba diver who surfaces unconscious or loses consciousness within 10 minutes after surfacing. Initiate basic life support, including administration of the highest fraction of oxygen. Because relapses can and do occur, divers suffering AGE should be rapidly evacuated to a hyperbaric oxygen treatment facility even if they appear to have recovered fully.

Decompression Sickness (“The Bends”)

Breathing air under pressure causes excess inert gas (usually nitrogen) to dissolve in and saturate body tissues. The amount of gas dissolved is proportional to, and increases with, the total depth and time a diver is below the surface. As the diver ascends, the excess dissolved gas must be cleared through respiration. Depending on the amount of gas dissolved and the rate of ascent, some gas can supersaturate tissues, where it separates from solution to form bubbles, interfering with blood flow and tissue oxygenation.

Other Conditions Related to Diving

Drowning

Any incapacitation while underwater can result in drowning (see Sec. 4, Ch. 12, Injury & Trauma).

Hazardous Marine Life

Oceans and waterways are filled with marine animals, most of which are generally harmless unless threatened. Most injuries among divers are the result of chance encounters or defensive maneuvers of marine life. Wounds from marine life have many common characteristics, including bacterial contamination, foreign bodies, bleeding, and occasionally venom. See Sec. 4, Ch. 7, Zoonotic Exposures: Bites, Stings, Scratches & Other Hazards, for prevention and injury management recommendations.

Immersion (Induced) Pulmonary Edema

The normal hemodynamic effects of water immersion account for a shift of fluid from peripheral to central circulation that can result in higher pressures within the pulmonary capillary bed, forcing excess fluid into the lungs. Cold water can cause peripheral vasoconstriction and augment this central fluid shift. Symptoms and signs of immersion (induced) pulmonary edema (IPE) generally begin on descent or at depth and include chest pain, dyspnea, wheezing, and productive cough with frothy, sometimes pink-tinged sputum. Although not entirely well understood, age, overhydration, overexertion, negative inspiratory pressure, and left ventricular hypertrophy are believed to increase IPE risk in otherwise healthy divers. Anyone experiencing acute pulmonary edema while diving requires a work-up to rule out myocardial ischemia, evaluation of left ventricular function, hypertrophy, and valvular integrity.

Nitrogen Narcosis

At increasing depths, generally >100 ft (≈30 m), the partial pressure of nitrogen within the breathing gas increases, causing narcosis in all recreational divers. Nitrogen narcosis can be life threatening when it impairs a diver’s ability to make appropriate and proper decisions while under water. This narcosis quickly clears on ascent and is not seen on the surface after a dive, which helps differentiate this condition from AGE.

Oxygen Toxicity

At increasing partial pressures of oxygen, levels in the blood become high enough to cause seizures. This condition is not seen when diving on compressed air within recreational depth limits.

Diving & Air Travel

Flying after Diving

The risk of developing decompression sickness increases when divers go to increased altitude too soon after a dive. Commercial aircraft cabins are generally pressurized to the equivalent of 6,000–8,000 ft (≈1,830–2,440 m) above sea level. Instruct asymptomatic divers to wait before flying at an altitude or cabin pressure >2,000 ft (610 m) for

• ≥12 hours after surfacing from a single no-decompression dive;
• ≥18 hours after multiple dives or multiple days of diving; or
• 24–48 hours after a dive that required decompression stops.

These recommended preflight surface intervals reduce, but do not eliminate, risk for DCS. Longer surface intervals further reduce this risk.

Diving after Flying

There are no guidelines for diving after flying. Divers should wait a sufficient period to acclimate mentally and physically to their new location to focus solely on the dive.

Preventing Diving Disorders

Recreational divers should dive conservatively and well within the no-decompression limits of their dive tables or computers. When multiple dives are planned, strict guidelines, known as surface intervals, are prescribed to allow adequate time for dissolved inert gas to drop to acceptable levels before the next dive. Tables derived from man-tested algorithms have traditionally been used by divers to manually calculate dive times and surface intervals. Dive computers possess the reliability and computing power to use the same algorithms and compute individual guidance based on real-time depth and time inputs. Dive computers have largely replaced the use of tables for the manual process of dive planning.

Risk factors for DCI are primarily dive depth, dive time, and rates of ascent. Additional factors, such as altitude exposure soon after a dive, difficult diving conditions (e.g., colder water, currents, decreased visibility, wave action), dives to depths >60 ft (18 m), multiple consecutive days of diving or repetitive dives, overhead situations (e.g., diving in underwater caves or wrecks), strenuous exercise, and certain physiologic variables (e.g., dehydration), also increase risk. Caution divers to stay well hydrated and rested and dive within the limits of their training. Diving is a skill that requires training and certification and should be done with a well-trained, attentive companion (dive buddy).

Treatment of Diving Disorders

Definitive treatment of DCI begins with early recognition of symptoms, followed by recompression with hyperbaric oxygen. Be suspicious of any unusual symptoms occurring soon after a dive, especially neurological symptoms, and evaluate these properly. Provide a high concentration (100%) of supplemental oxygen; surface-level oxygen given for first aid might relieve the signs and symptoms of DCI and should be administered as soon as possible.

Because of either incidental causes, immersion, or DCI itself, which can cause capillary leakage, divers often are dehydrated. In most cases, treatment includes administering isotonic glucose-free intravenous fluids. Oral rehydration fluids also can be helpful, provided they can be administered safely (i.e., if the diver is conscious and can maintain their airway).

The definitive treatment of DCI is recompression and oxygen administration in a hyperbaric chamber. Stable or remitting symptoms of mild DCI (e.g., constitutional symptoms, some cutaneous sensory changes, limb pain, or rash) in divers reporting from remote locations without a hyperbaric facility might not require recompression. Medical management decisions made with the assistance of a qualified dive medicine physician also should account for the prevailing circumstances, logistics and hazards of evacuation, and the implications of failing to recompress. Serial neurologic exams are essential to the decision-making process.

Divers Alert Network (DAN) maintains 24-hour emergency consultation and evacuation assistance at +1-919-684-9111 (collect calls accepted). DAN can help with the medical management of injured divers by deciding if recompression is needed, providing the location of the closest recompression facility, and arranging patient transport. Divers and health care providers also can contact DAN for routine, nonemergency consultation by telephone at 919-684-2948, extension 6222, or by accessing the DAN.

Travelers who plan to scuba dive might want to ascertain whether recompression facilities are available at their destination before embarking on their trip.

The following authors contributed to the previous version of this chapter: Daniel A. Nord, Gregory A. Raczniak, James M. Chimiak

Brubakk AO, Neuman TS, Bennett PB, Elliott DH. Bennett and Elliott’s physiology and medicine of diving, 5th edition. London: Saunders; 2003.  

Chapter 6: Pulmonary and Venous Disorders. In: J. Chimiak, editor. The heart & diving. Durham (NC): Divers Alert Network. Available from: https://dan.org/wp-content/uploads/2020/07/the-heart-and-diving-dan-dive-medical-reference.pdf. 

Dear G, Pollock NW. DAN America dive and travel medical guide, 5th edition. Durham, NC: Divers Alert Network; 2009. 

Divers Alert Network. Flying after diving. 2003. Available from: https://dan.org/research-reports/research-studies/flying-after-diving. 

Mitchell SJ, Doolette DJ, Wachholz, CJ, Vann RD, editors. Management of mild or marginal decompression illness in remote locations. Sydney, Australia: Undersea and Hyperbaric Medical Society; 2004. 

Moon RE. Treatment of decompression illness. In: Bove AA, Davis JC, editors. Bove and Davis’ diving medicine, 4th edition. Philadelphia: WB Saunders; 2004. pp. 195–223. 

Neuman TS, Thom SR. Physiology and medicine of hyperbaric oxygen therapy. Philadelphia, PA: Saunders; 2008.  

US Navy. The Navy diving manual revision 7. USA: Carlisle Military Library; 2018.

Decompression Sickness – Injuries and Poisoning

By

Richard E. Moon

, MD, Duke University Medical Center

Reviewed/Revised Apr 2023

VIEW PROFESSIONAL VERSION

Decompression sickness is a disorder in which nitrogen dissolved in the blood and tissues by high pressure forms bubbles as pressure decreases.

• Symptoms can include fatigue and pain in muscles and joints.

• In the more severe type, symptoms may be similar to those of stroke or can include numbness, tingling, arm or leg weakness, unsteadiness, vertigo (spinning), difficulty breathing, and chest pain.

• People are treated with oxygen and recompression Recompression Therapy Recompression therapy involves giving 100% oxygen for several hours in a sealed chamber at high pressures (at least 1. 9 atmospheres). (See also Overview of Diving Injuries.) Recompression therapy… read more (high-pressure, or hyperbaric, oxygen) therapy.

• Limiting the depth and duration of dives and the speed of ascent can help with prevention.

(See also Overview of Diving Injuries Overview of Diving Injuries People who engage in deep-sea or scuba diving are at risk of a number of injuries, most of which are caused by changes in pressure. These disorders also can affect people who work in underwater… read more .)

Air is composed mainly of nitrogen and oxygen. Because air under high pressure is compressed, each breath taken at depth contains many more molecules than a breath taken at the surface. Because oxygen is used continuously by the body, the extra oxygen molecules breathed under high pressure usually do not accumulate. However, the extra nitrogen molecules do accumulate in the blood and tissues.

As outside pressure decreases during ascent from a dive or when leaving a compressed air environment, the accumulated nitrogen that cannot be exhaled immediately forms bubbles in the blood and tissues. These bubbles may expand and injure tissue, or they may block blood vessels in many organs—either directly or by triggering small blood clots. This blood vessel blockage causes pain and various other symptoms, for example, sometimes similar to those of a stroke (such as sudden weakness on one side of the body, difficulty speaking, or dizziness), or even flu-like symptoms. Nitrogen bubbles also cause inflammation, causing swelling and pain in muscles, joints, and tendons.

The risk of developing decompression sickness increases with many of the following factors:

• Certain heart defects, such as patent foramen ovale or atrial septal defect Atrial and Ventricular Septal Defects Atrial and ventricular septal defects are holes in the walls (septa) that separate the heart into the left and right sides. Holes can be present in the walls of the heart between the upper heart… read more

• Cold water

• Dehydration

• Flying after diving

• Exertion

• Fatigue

• Increasing pressure (that is, the depth of the dive)

• Length of time spent in a pressurized environment

• Obesity

• Older age

• Rapid ascent

• Failure to follow appropriate decompression procedures

Because excess nitrogen remains dissolved in the body tissues for at least 12 hours after each dive, repeated dives within 1 day are more likely to cause decompression sickness than a single dive. Flying within 12 to 24 hours after diving (such as at the end of a vacation) exposes people to an even lower atmospheric pressure, making decompression sickness slightly more likely.

Nitrogen bubbles may form in small blood vessels or in the tissues themselves. Tissues with a high fat content, such as those in the brain and spinal cord, are particularly likely to be affected, because nitrogen dissolves very readily in fats.

• Type I decompression sickness tends to be mild and affects primarily the joints, skin, and lymphatic vessels.

• Type II decompression sickness, which may be life threatening, often affects vital organ systems, including the brain and spinal cord, the respiratory system, and the circulatory system.

Symptoms of decompression sickness usually develop more slowly than do those of air embolism Arterial Gas Embolism Arterial gas embolism is blockage of blood supply to organs caused by bubbles in an artery. It is a leading cause of death among underwater divers, such as scuba divers, who breathe compressed… read more and pulmonary barotrauma Pulmonary barotrauma Barotrauma is tissue injury caused by a change in pressure, which compresses or expands gas contained in various body structures. The lungs, gastrointestinal tract, part of the face covered… read more . Only half of the people with decompression sickness have symptoms within 1 hour of surfacing, but 90% have symptoms by 6 hours. Symptoms commonly begin gradually and take some time to reach their maximum effect. The first symptoms may be

The less severe type (or musculoskeletal form) of decompression sickness, often called the bends, typically causes pain. The pain usually occurs in the joints of the arms or legs, back, or muscles. Sometimes the location is hard to pinpoint. The pain may be mild or intermittent at first but may steadily grow stronger and become severe. The pain may be sharp or may be described as “deep” or “like something boring into bone. ” It is worse when moving.

Less common symptoms include itching, skin mottling, rash, swelling of the arm, chest, or abdomen, and extreme fatigue. These symptoms do not threaten life but may precede more dangerous problems.

The more severe type of decompression sickness most commonly results in neurologic symptoms, which range from mild numbness to paralysis and death. The spinal cord is especially vulnerable.

Symptoms of spinal cord involvement can include numbness, tingling, weakness, or a combination in the arms, legs, or both. Mild weakness or tingling may progress over hours to irreversible paralysis. Inability to urinate or inability to control urination or defecation may also occur. Pain in the abdomen and back also is common.

Symptoms of brain involvement, most of which are similar to those of air embolism, include

• Headache

• Confusion

• Trouble speaking

• Double vision

Loss of consciousness is rare.

Symptoms of inner ear involvement, such as severe vertigo, ringing in the ears, and hearing loss, occur when the nerves of the inner ear are affected.

Symptoms of lung involvement caused by gas bubbles that travel through the veins to the lungs, produce cough, chest pain, and progressively worsening difficulty breathing (the chokes). Severe cases, which are rare, may result in shock and death.

Dysbaric osteonecrosis (sometimes called avascular bone necrosis) can be a late effect of decompression sickness, or can occur in the absence of decompression sickness. It involves the destruction of bone tissue, especially in the shoulder and hip. Dysbaric osteonecrosis Osteonecrosis can produce persistent pain and disability due to osteoarthritis resulting from the injury. These injuries rarely occur among recreational divers but are more common among people who work in a compressed-air environment and divers who work in deep underwater habitats. There is often no specific initiating event the person can identify as the source of symptoms once they do appear.

These workers are exposed to high pressure for prolonged periods and may have an undetected case of the bends. Technical divers, who dive to greater depths than recreational divers, may be at higher risk than recreational divers. Dysbaric osteonecrosis usually produces no symptoms but if it occurs close to a joint it may gradually progress over months or years to severe, disabling arthritis. By the time severe joint damage has occurred, the only treatment may be joint replacement.

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. However, recompression therapy is begun before the results of a CT or MRI scan are available, except in cases in which the diagnosis is uncertain or the diver’s condition is stable. MRI is usually diagnostic of dysbaric osteonecrosis.

• Oxygen

• Sometimes recompression therapy Recompression Therapy Recompression therapy involves giving 100% oxygen for several hours in a sealed chamber at high pressures (at least 1.9 atmospheres). (See also Overview of Diving Injuries.) Recompression therapy… read more

The majority of people recover completely.

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. Breathing 100% oxygen from a close-fitting face mask is recommended and may provide relief.

Any other symptoms of decompression sickness indicate the need for treatment in a high-pressure (recompression, or hyperbaric oxygen) chamber, because recompression therapy Recompression Therapy Recompression therapy involves giving 100% oxygen for several hours in a sealed chamber at high pressures (at least 1.9 atmospheres). (See also Overview of Diving Injuries.) Recompression therapy… read more restores normal blood flow and oxygen to affected tissues. 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 is more beneficial when started quickly. When flying in a plane, the air pressure in the passenger compartment is lower than on the ground, and this pressure difference can sometimes worsen decompression sickness. However, in people with severe symptoms, the benefit of being treated sooner in a hyperbaric chamber is much greater than the risk of not being treated. Experts usually recommend flying in a commercial aircraft, which can be pressurized, or flying at low altitude if the aircraft is unpressurized.

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.

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 U. S. Navy Diving Manual.

The table provides a schedule for ascent that usually allows excess nitrogen to escape without causing harm. Many divers wear a portable dive computer that continually tracks the diver’s depth and time at depth. 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 (4.5 meters) below the surface.

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.

Did You Know.

..

Other precautions also are necessary:

• 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.

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

• Divers Alert Network: 24-hour emergency hotline, 919-684-9111

• Duke Dive Medicine: 24-hour emergency consultation with a doctor, 919-684-8111

• U. S. Navy Diving Manual: Detailed reference guide published by the United States Navy detailing diver training and diving operations

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This is the Consumer Version.


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Symptoms, Causes and Treatment of Decompression Sickness

Learn about decompression sickness or decompression sickness that occurs when diving at depth and how to prevent it. Read about the main symptoms and treatments for this disease.

Decompression sickness is a serious illness that can affect anyone who works in deep water, including divers, oil rig workers, and high-altitude workers. The disease occurs due to the peculiarities of pressure on the body and is a consequence of insufficient decompression after leaving the deep conditions.

Symptoms of decompression sickness can include joint pain, dizziness, double vision, incoordination and other effects that can lead to injury and even death. The causes of the caisson disease are that when diving into the depths, the body is saturated with decompression gases, which should decrease gradually when reaching the surface. If this process is impossible, gas exchange processes are disturbed and decompression sickness occurs.

“Rapid ascent for humans means rapid stress on the cardiovascular system,” say decompression sickness experts.

There are various treatments for decompression sickness such as hyperbaric oxygen therapy, medical gas therapy and rehabilitation. But the best way to prevent decompression sickness is to strictly follow the prevention and safety instructions for working under pressure, to have regular medical check-ups, and to be trained before working at depth or height. ”

Decompression sickness is a dangerous disease that develops in people at great depths and during ascent to the surface. It occurs due to a decrease in ambient pressure and a change in the composition of the inhaled air.

There are several types of decompression sickness, which differ in their symptoms and manifestations. One of them is decompression sickness, which occurs due to the rapid change in pressure and exposure to nitrogen in the body. Another type is decompression fever, which is characterized by a sharp deterioration in health.

Decompression sickness is a serious disease that can lead to death, so it is important to take all safety precautions when diving and resurfacing. If symptoms of decompression sickness appear, you should immediately consult a doctor.

Decompression sickness is the result of a diver quickly exiting deep waters without a sufficient decompression period. This can happen due to a variety of reasons, including errors in dive planning, equipment problems, incorrect decompression procedures, or unforeseen circumstances such as rough seas or strong currents.

Deep diving is also a risk factor for decompression sickness. The deeper the diver dives, the more nitrogen accumulates in his tissues. If proper exit decompression procedures are not followed, nitrogen can be released too quickly, causing painful symptoms.

Certain medical conditions may also increase the risk of decompression sickness, including diabetes, hypertension, and atherosclerosis. There is also a theory that some people may have a higher sensitivity to nitrogen buildup in their tissues, which may make them more susceptible to developing decompression sickness in the face of inexperience with decompression.

Irregular diving practice can also cause decompression sickness. If a diver rarely dives, his body may not have time to adapt to the decompression procedure, which increases the risk of illness.

Q&A:

What are the symptoms of decompression sickness?

Symptoms of decompression sickness can vary, but the most common are joint and muscle pain, breathing problems, dizziness, nausea, vomiting, incoordination, convulsions, loss of sensation in different parts of the body. All this is due to the accumulation of gases in the blood and tissues.

What are the causes of decompression sickness?

The main cause of decompression sickness is a rapid change in pressure during a dive or resurfacing. In addition, decompression sickness can occur when diving too quickly, or diving too deep for one’s skill level.

How is decompression sickness treated?

Decompression sickness is treated in a hyperbaric chamber where the patient is pressurized and given pure oxygen to breathe. Due to this, gases begin to quickly leave the tissues, swelling decreases and normal blood circulation is restored. In addition, patients may be prescribed anti-inflammatory and pain medications.

What are the consequences of decompression sickness?

The consequences of decompression sickness can be very serious or even fatal if treatment is not started on time. This can lead to disruption of the brain, heart, lungs, liver, kidneys and other organs. In some cases, the effects of decompression sickness can last a lifetime.

How can decompression sickness be prevented?

To prevent decompression sickness, you must follow the safety rules when diving. Never lower depth too quickly or rise to the surface too abruptly. You also need not to overestimate your strength and competently plan the dive. It is extremely important to conduct decompression stops in accordance with the decompression tables that are appropriate for your level of training and the depth of the dive.

How likely is it to get decompression sickness?

The likelihood of getting decompression sickness depends on many factors, including the level of training, the depth of the dive, the time spent at depth, heat, and others. However, if you follow all the rules and safety recommendations, the likelihood of getting decompression sickness is minimal.

How does decompression sickness manifest itself?

Decompression sickness is a serious illness that occurs in people who work under extreme conditions, such as diving for long periods at shallow depths.

The main symptoms of decompression sickness are: sensation of pain, burning and numbness in various parts of the body. The reason for this is the formation of gas bubbles in tissues and blood vessels, which leads to dysfunction of various organs.

Damage to the nervous system is also one of the symptoms of decompression sickness. The person may experience weakness in the limbs, weakness in the muscles, and difficulty moving. In more severe cases, convulsions, loss of consciousness and even death are possible.

In addition, people with decompression sickness may experience high blood pressure, tinnitus, and difficulty breathing. These symptoms require immediate medical attention, as they can lead to serious consequences.

It is important to note that the symptoms of decompression sickness may not appear immediately, but several hours after exposure to adverse conditions. Therefore, it is important to monitor your health and promptly seek help if any unusual sensations or symptoms appear.

Complications of decompression sickness

Decompression sickness can lead to serious complications if symptoms are not treated. The most common complication is decompression sickness. It occurs when nitrogen bubbles form in tissues and blood vessels.

Other possible complications of decompression sickness are pulmonary edema, cerebral edema, corkscrew deformity of the hands and feet. Dropsy of the lungs occurs when nitrogen bubbles form in the lungs, causing multiple microclots and embolism. Cerebral edema can lead to deafness, paralysis, and seizures. Corkscrew deformity of the hands and feet can cause painful symptoms such as pain and numbness.

If left untreated, decompression sickness can become a chronic condition. This can lead to consequences such as psychological problems, psychomotor developmental disorders, and psychiatric disorders.

In general, you should pay attention to the symptoms of decompression sickness and seek medical attention immediately. Dentists and other healthcare professionals can develop prevention and treatment strategies to avoid these complications.

How is decompression sickness diagnosed?

Diagnosis of decompression sickness includes a number of methods that help assess the state of the body and identify signs of the disease.

First, the doctor performs a detailed examination of the patient, finds out his symptoms and the history of recent activity and travel. Particular attention is paid to long-standing or recurring diseases, organ dysfunctions, the presence of injuries and operations.

Then, a physical examination is performed, including measurement of pressure, pulse, auscultation of the lungs and examination of the abdominal organs. The doctor draws attention to the possible symptoms of decompression sickness, such as joint pain, visual impairment, dizziness, etc.

Additional tests, such as X-ray or MRI scan, blood and urine tests, may be required to confirm the diagnosis. These methods help to determine the presence of gas bubbles that appear during decompression, as well as areas of damage to tissues and organs.

Typically, symptoms of decompression sickness appear immediately after diving or after a few hours, but sometimes they can appear after a few days. If you suspect decompression sickness, you should immediately consult a doctor for diagnosis and treatment.

Treatment of decompression sickness

Decompression therapy

This therapy is aimed at restoring normal pressure in the tissues and circulatory system, alleviating the patient’s condition and reducing the symptoms of the disease.

1. The main method is hyperbaric oxygen therapy (HBOT), which is carried out in specialized clinics.
2. Other methods are also used to treat decompression sickness, such as oxygenation of tissues and drainage of the lungs and heart.

Symptomatic treatment

The main goal of this treatment is to eliminate the symptoms of decompression sickness and alleviate the patient’s condition.

• Anti-inflammatory and analgesic drugs are used to relieve pain and reduce inflammation.
• In case of heart dysfunction, drugs are prescribed to improve blood circulation and heart function.
• Diuretics and drugs that improve urination are used to reduce swelling.

Oxygen Therapy

This treatment aims to increase the amount of oxygen in the tissues and blood.

• The patient is prescribed oxygen therapy for several days, which takes place under the supervision of doctors.
• This method helps to reduce the symptoms of decompression sickness and improve the general condition of the body.

How to prevent decompression sickness?

Decompression sickness is a serious condition that can lead to dangerous consequences. However, there are several ways to protect yourself from this disease:

• Follow instructions: When diving or diving in a pool, it is important to follow the instructor’s instructions. He will tell you about security and how to proceed in case of problems.
• Be in good shape: Decompression sickness often occurs in people who are not physically fit enough. This can increase the risk of decompression sickness. Before diving, it is important to make sure that your body is ready for physical activity.
• Don’t miss the mandatory stops: Stops must always be observed when lifting out of the water. They allow your body to slowly adapt to changes in pressure. It is not recommended to skip these stops.
• Drink water: When diving, it is important to drink water to prevent dehydration. This helps your body better adapt to changes in pressure.
• Do not dive if you are sick: If you are sick it is not recommended to dive. Infections and other illnesses can increase the risk of decompression sickness.

These are just a few of the ways you can help prevent decompression sickness. However, the most important advice is to be careful and not risk your health.

Treatment of decompression sickness in children

Children are particularly susceptible to decompression sickness because they may not feel comfortable inside the diving equipment or know how to use it correctly. Treatment for decompression sickness in children may differ from that in adults, and their age and physical characteristics must be taken into account.

One of the main treatments for decompression sickness in children is hyperbaric oxygen therapy, which allows children to restore normal oxygen levels in tissues and organs after decompression. Another method of treatment is to restore fluid balance and maintain normal blood pressure, which increases the effectiveness of hyperbaric oxygen therapy and reduces the risk of recurrent cases of decompression sickness.

However, in addition to hyperbaric oxygen therapy and fluid balance, treatment of decompression sickness in children may also include other methods, depending on the symptoms and severity of the disease. For example, the use of anti-inflammatory drugs can help reduce pain and improve the patient’s condition. In addition, if decompression sickness has caused damage to the nervous system, then neurological treatment is carried out, which may include rehabilitation procedures and physical therapy.

In general, the treatment of decompression sickness in children requires a comprehensive approach and an individual approach to each patient. It is important to evaluate disease severity, symptoms, and other factors when choosing and sequencing treatments to ensure the best treatment outcome and prevent recurrence of decompression sickness in the future.

Decompression sickness and its effect on pregnancy

What is decompression sickness?

Decompression sickness is a condition that occurs in people who quickly return to the surface after diving to great depths. This can happen if diving has not been properly planned and precautions have not been taken. Symptoms of decompression sickness can be complex and include joint pain, dizziness, memory loss, and others.

Effect of decompression sickness on pregnancy

Pregnant women may experience a number of complications if they have had decompression sickness. Symptoms may include miscarriages, premature births, and congenital malformations in the fetus. The reason for this is that the oxygen balance between the mother and the fetus can be disturbed, which can lead to problems with the development of the fetus.

Treatment of decompression sickness in pregnancy

If a pregnant woman experiences decompression sickness, it is important to see a doctor as soon as possible. Treatment may include oxygen therapy, special medications, and, in some cases, a hyperbaric chamber. However, given the possible complications, it is best to avoid diving during pregnancy and talk to your doctor about it.

How quickly can you return to scuba diving after decompression sickness?

It is possible to return to scuba diving after decompression sickness only after full recovery of health and passing the necessary treatment procedures. Each case is individual, so the exact time required for recovery depends on the severity of the disease and the nature of its manifestation.

The doctor supervising the treatment of the patient, at a certain level of health recovery, may advise small, small and careful dives to assess how deep and how long you can stay underwater. However, it is only possible to determine when a patient is ready to return to full diving after a full course of rehabilitation treatment has been completed.

In addition to mandatory medical procedures, special exercise, diet and a general healthy lifestyle can help restore health and increase the necessary endurance. The doctor can prescribe the appropriate exercises for the patient to help him return to a full life and scuba diving more quickly.

Fear of decompression sickness: myths and reality

Myth: Decompression sickness is a disease that can happen to anyone who goes underwater. Only short-term dives to shallow depths are safe.

Reality: Decompression sickness occurs in people who dive to considerable depths. A similar problem can be experienced divers who have repeatedly gone to deep depths. The safety of diving depends on the experience of the diver and the correct implementation of all necessary procedures.

Myth: Decompression sickness can be avoided by quickly resurfacing.

Reality: A sudden exit to the surface will only worsen the situation. This can cause microembolism, which can lead to ultrasonic lime deposits in the lungs, brain, and bones.

• Myth: Decompression sickness is a rare disease that few people experience.
• Reality: Decompression sickness is a serious disease that can lead to complications and even death. Illness occurs more often than you might think, so before certain types of diving, you should consult an expert.

Do not forget that decompression sickness is a serious risk created by the process of gas exchange in the human body when diving to great depths. Therefore, it is necessary to be trained by qualified instructors and take all necessary precautions to avoid the occurrence of this disease.

causes, symptoms, risk group, treatment

1. How does decompression sickness occur?
2. Consequences of decompression sickness
3. Severity of decompression sickness
4. Chronic decompression sickness
5. Symptoms of diving illness
6. Complications of DCS
7. Diagnostics
8. Treatment

Image by chayanuphol on Shutterstock

Decompression sickness is a pathological condition in which gas bubbles form in the vessels and tissues of the body. This is due to the rapid decrease in atmospheric pressure. Otherwise, the disease is called decompression sickness (DCS).

The name “caisson” comes from the word “caisson”. This device was invented in the XIX century for underwater work. The design was a chamber in which a person descended into the water. First, decompression sickness was diagnosed by specialists in underwater work. Over time, its distribution has become wider. Sometimes this condition occurs in pilots who, when changing flight altitude, are exposed to changes in atmospheric pressure. However, divers are more susceptible to this disease than others. Diving enthusiasts cannot always cope with the transition from high pressure to normal, which is why they develop “diver’s disease”. According to statistics, up to 4 cases of decompression sickness are recorded per 10 thousand dives. It can be not only acute, but also chronic.

To prevent the disease, you should use high-quality breathing mixtures when diving, avoid a sharp rise from the depth to the surface, observe the intervals between dives or flights, and undergo preventive examinations if a person works underwater.

How decompression sickness occurs

The main reason for the formation of air bubbles in organs and tissues is a sharp decrease in atmospheric pressure when ascending to a height or water surface after diving. However, there are factors that increase the risk of developing “diver’s disease”:

• age changes. With age, the heart and lungs are harder to cope with stress, so decompression sickness is more common in middle-aged and mature people than in young people;

• hypothermia. Cold impairs the blood supply to organs and tissues. This is especially true for peripheral vessels. Because of this, the pulmonary vessels receive less blood, which leads to gas retention and the formation of bubbles;

• increased blood viscosity. This condition occurs when you are dehydrated. The blood flow slows down, there is stagnation of blood in the peripheral vessels;

• intoxication. Drinking alcohol before diving is life-threatening. Alcohol provokes dehydration, and with the content of alcohol in the blood, air bubbles become larger and can clog the lumen of the vessel;

• overweight. If the body contains a large percentage of adipose tissue, bubbles form faster due to the hydrophobicity of fat. In addition, fats tend to dissolve inert gases from the breathing mixtures used by divers;

• increase in carbon dioxide concentration. This condition is called hypercapnia. It occurs when using poor-quality mixtures or when breathing improperly under water. With an increase in the concentration of CO2 in the blood, more inert gases are dissolved;

• exercise stress. Under load, blood flow becomes uneven. Gases in the blood dissolve more rapidly and air bubbles appear. As a rule, they are very small in size and are localized in the area of ​​​​the joints. On subsequent dives, decompression sickness may become more pronounced.

Consequences of decompression sickness

When immersed in water, atmospheric pressure rises. Because of this, the gases of the respiratory mixtures dissolve in the blood of the capillaries of the tissues of the lungs. After ascent, when the pressure returns to normal limits, the opposite occurs. Gases dissolved in the blood form bubbles. If the diver ascends quickly, that is, the body does not have time to adapt. If the rate of ascent is not observed, the blood seems to “boil”. At this point, not only small, but also large bubbles are formed. They attract platelets to themselves, increasing in size. These compounds can cause thromboembolism – blockage of the lumen of the vessel.

When a large number of such bubbles with platelets appear in the blood, a gas embolism develops. Circulating through the bloodstream, these compounds can damage the walls of blood vessels, provoking hemorrhage.

In addition to vessels, bubbles can be found in the joint cavities and soft tissues. Gas compounds compress the nerve endings, cause pain throughout the body. In addition, there may be foci of necrosis in the muscles and internal organs, which is also caused by compression.

Severity of decompression sickness

Depending on the symptoms, three degrees of severity of the disease are distinguished:

• light. With a mild degree of pathology, the patient experiences pain in the muscles and joints, which is associated with pressure on the nerve endings of air bubbles. Due to blockage of superficial vessels and sweat glands, itching of the skin begins, it becomes more oily;

• average. Pathology of moderate severity causes a deterioration in coordination of movements, visual impairment, and a disorder in the functioning of the digestive tract. This is due to the accumulation of gases in the vessels of the mesentery and intestines;

• heavy. The main symptom of pathology is damage to the spinal cord due to compression of the nervous tissue. In some cases, the brain is involved in the pathological process. This is manifested by disorders in the work of the heart and respiratory system. In addition, in a particularly severe stage, air bubbles block vital vessels, which leads to a cessation of the blood supply to the lung tissue, a person develops acute heart failure.

Even with moderate severity of pathology, acute “diver’s disease” can lead to severe damage to organs and systems. If left untreated, these conditions are life threatening.

Chronic decompression sickness

This type of pathology is quite rare. It affects people who perform professional work at depth every day or regularly go in for scuba diving.

Symptoms of illness in divers

Beginners are not always able to recognize the symptoms of decompression sickness, because they increase gradually. The exceptions are the most severe degrees of the disease, in which a person feels unwell from the first minutes after surfacing. In most people, the first signs of pathology appear within an hour and gradually increase over five to six hours. The least common is delayed decompression sickness. It appears 1-2 days after the dive.

Symptoms depend on the degree of the disease. Patients with a mild form of pathology feel pain in the back and joints. Usually, the shoulders and elbows hurt the most, and the pain gets worse with movement. A rash or “marble” pattern may appear on the skin. Changes are accompanied by itching. Some people have enlarged lymph nodes.

If the degree of damage is more severe, the patient is dizzy and has a headache, hearing deteriorates, sweating appears, and the skin turns pale. A person cannot engage in habitual activities due to flies and fog before his eyes. There are also pains in the abdomen, which are accompanied by nausea and vomiting, loose stools.

In patients with severe decompression sickness, the sensitivity of the lower body is disturbed, spasms, problems with urination and defecation are observed. If the brain is involved in the pathological process, headaches appear, a temporary speech disorder develops, and hearing deteriorates.

Patients with severe DCS require urgent treatment due to impaired respiratory and cardiac function. The disease manifests itself as weakness and shortness of breath, chest pain, and a decrease in pressure. In the absence of medical care, acute oxygen deficiency develops, pulmonary edema may also develop, and the risk of myocardial infarction increases. Breathing becomes superficial, the skin turns pale, becomes cyanotic.

In the lethal form of the disease, death occurs due to severe heart failure, which is caused by impaired blood circulation in the lungs or depression of the respiratory center located in the brain.

If the disease proceeds in a chronic form, the joints and bones primarily suffer. This leads to the development of deforming arthrosis. Divers may experience irregularities in the work of the heart. The opinions of specialists about cardiac pathologies against the background of decompression sickness diverge. Many are sure that regular stay at depth contributes to the earlier development of atherosclerosis, myodegeneration of the heart.

Complications of DCS

Most often, patients suffer from chronic Meniere’s syndrome, in which the pathology affects the middle ear. The person experiences dizziness, hearing gradually deteriorates. Another possible disorder is aeropathic myelosis, which is a lesion of bone marrow cells.

In moderate and severe variants of the disease, all kinds of cardiac pathologies of an inflammatory and degenerative nature occur. Among the most common are endocarditis and myocarditis, cardiosclerosis. On the part of the respiratory system, pneumonia may develop. Of the neurological manifestations of the disease, paresis, muscle paralysis, loss of sensitivity are most often noted.

Diagnostics

With signs of DCS, you should contact a traumatologist. Depending on the form of the disease and its manifestations, cardiologists and neurologists are also involved in treatment. The doctor examines the patient, collects an anamnesis. Of the hardware procedures, ECG, X-ray, ultrasound of internal organs, CT and MRI are prescribed.

Without fail, the doctor evaluates the work of the heart and lungs, the state of the spinal cord and brain. When examining an x-ray, you can see gas bubbles in the tissues and joints, which confirms decompression sickness.

Treatment

With minor manifestations of the disease, the patient is at home or in the hospital under the supervision of a doctor. With moderate and severe degrees, it is necessary to carry out recompression, which takes place in the pressure chamber and allows you to normalize the patient’s condition.

Recompression consists of several stages. First, the pressure rises, as if the person is again at depth. In such conditions, a person is from half an hour or more. After normalization of the state, the pressure is gradually reduced, simulating the rise to the surface of the water. Oxygen is also supplied, which will displace nitrogen from the blood. In some cases, the procedure has to be repeated.

If the patient has developed complications, then symptomatic treatment, physiotherapy are prescribed. According to statistics, 80% of people with “diver’s disease” return to their former lives without health consequences with timely treatment.