Dysbarism

What is Dysbarism?

Dysbarism refers to any harmful medical condition caused by changes in the surrounding pressure. These pressure changes should be either too fast or last too long for the body to adjust to safely. The term dysbarism includes a number of conditions like decompression sickness, nitrogen narcosis, high-pressure neurological syndrome, barotrauma, and arterial gas embolism.

What Causes Dysbarism?

Dysbaric injuries, or injuries caused by changes in pressure, most often happen during underwater diving. However, they can also occur anytime a person is exposed to a setting with intense pressure changes. This could be instances such as being at high altitudes, during an aircraft cabin decompression, amidst explosions or blasts, in outer space, within underwater construction sites known as caissons, and during operations to bore tunnels.

Risk Factors and Frequency for Dysbarism

Scuba diving is a popular recreational activity, with over 9 million people participating in the United States and the number is still growing. As more people dive, the number of injuries caused by the changes in pressure, also known as ‘dysbarism’, is also on the rise. Every year, the Diver’s Alert Network reports more than 1000 injuries related to diving, but less than 1% of divers develop Decompression Sickness (DCS).

Barotrauma – an injury caused by a change in air pressure – is the most common diving-related injury.
The most common complaint among divers is middle ear barotrauma.
Pulmonary barotrauma, another type of pressure-related injury that affects the lungs, is the second most common cause of diver’s death, after drowning.

Signs and Symptoms of Dysbarism

When examining a patient with a diving-related medical issue, the process may feel unclear, and the patient’s symptoms and signs might change over time. This is why it’s critical to focus on the patient’s diving history and symptoms. To understand their history, ask about how often and how deep the divers go, if they’ve experienced rapid ascension or other diving troubles, their level of experience, the quality of the equipment they use, and whether they’ve had decompression illnesses before.

It’s also crucial to ask about when symptoms first started. Identifying when within a dive these signs appeared can help distinguish between different diving-related illnesses. In general, barotrauma happens during descent, gas toxicity usually occurs at depth, and decompression illness (DCI) typically happens during or after the ascent. Arterial gas embolism (AGE) symptoms tend to occur within minutes of returning to the surface, whereas DCI symptoms can take hours to appear. AGE will often present with lung and brain problems, while DCI tends to create more joint and spinal cord issues. Lastly, the patient’s past medical history and risk factors for dysbarism, such as dehydration, upper respiratory infections, allergies, intensive physical work, poor fitness, and older age, should be considered.

During a physical examination, the doctor will check the patient’s ears, lungs, skin, joints, and nervous system. Many patients with minor DCI have normal exams, vitals, and mental status. More severe cases might involve significant neurological abnormalities, such as paralysis. In the ear and lung exams, the doctor should look for signs of otic or lung barotrauma. A comprehensive neurological exam is critical to identify any subtle signs of injury, which might include checking cranial nerves, motor skills, sensory skills, reflexes, balance, cerebellar function, and basic mental status.

Testing for Dysbarism

Diagnostic tests, including lab tests and scans, may not be extremely useful in diagnosing this particular condition, but they can assist in excluding other similar conditions. For instance, a chest X-ray can reveal any changes due to barotrauma (injury caused by changes in air pressure) or instances of nearly drowning. It is crucial to use this to rule out pneumothorax (collapsed lung) before deciding on recompression therapy.

Computed tomography (CT) and magnetic resonance imaging (MRI) scans are typically normal in such circumstances, but they can help identify alternative causes of the patient’s symptoms. In rare situations, a brain CT or MRI may show air densities in the small branches of arteries. Lab tests could show an increase in the concentration of blood cells or a rise in levels of creatine phosphokinase, an enzyme found in the heart, brain, and skeletal muscles, particularly in cases of arterial gas embolism (AGE), which is a bubble of gas blocking an artery.

Treatment Options for Dysbarism

When people present with symptoms of dysbarism, which are pressure-related injuries often associated with diving, these symptoms are often unclear and show up late. Consequently, it’s important to start treatment quickly. With decompression illness (DCI), an accurate diagnosis typically is not confirmed until there is a visible response to the treatment.

In cases of DCI, treatment starts with checking and making sure that the patient’s airways are open, that they’re breathing well, and that their circulation is good. This is typically done in an emergency setting. It’s important to start giving them 100% oxygen as quickly as possible and reach out to the nearest hyperbaric center, a medical facility that can deliver oxygen treatment under pressure. Compressing the patient again should always be done in a hyperbaric chamber, as trying to do it in-water can be very dangerous and requires a lot of advanced planning and equipment. These treatments help to minimize the size of any bubble-like structures and provide support to areas that deprived of oxygen and those at risk of further damage caused by reduced blood flow.

When dysbarism leads to a tympanic membrane rupture, or a rupture in the eardrum, the treatment involves keeping the ear dry and letting it drain. Ear drops are generally not recommended unless an infection begins to develop. It’s important for the patient to see an ear, nose, and throat specialist for follow-up. Usually, no further interventions are required as the perforations typically heal within six weeks on their own. Very rarely, grafting is needed to repair the eardrum.

The treatment for inner ear barotrauma is similar to that for middle ear barotrauma and involves rest and medications to help with dizziness. Patients should avoid blowing their nose. It’s not necessary to undergo hyperbaric oxygen recompression or oxygen treatment unless the patient also shows signs of decompression sickness or gas embolism, both of which are different types of dysbarism.

When trying to identify the condition known as dysbarism, there are various other health problems that doctors need to look out for due to their similar symptoms. These can include:

Narrowly avoiding drowning leading to a lack of oxygen to the brain
Injuries to the middle ear or sinus due to pressure changes
Infections of the sinus or ear
Injuries to the inner ear due to pressure changes
Poisoning by carbon monoxide or other harmful gases
Physical injuries to the muscles or skeleton
Low blood sugar, also known as hypoglycemia
Migraine headaches
Guillain-Barre syndrome, a rare neurological disorder
Multiple sclerosis, a disease affecting the nerves
Transverse myelitis, inflammation of the spinal cord
Compression of the spinal cord
Seizures
Stroke, which is caused by a disruption of blood supply to the brain
Heart attack, also known as myocardial infarction
Bleeding in the area surrounding the brain
Poisoning from seafood
Poisoning from an animal or insect sting
Side effects from certain medications, like mefloquine

Given these possibilities, doctors need to perform comprehensive tests and assessments to make a precise diagnosis.

What to expect with Dysbarism

The outlook for barotrauma, a condition caused by changes in pressure, is generally good as the condition often resolves itself. However, one serious complication, known as AGE, can be fatal if not treated properly with a therapy known as HBO2. Recent studies suggest that the mortality rates for this complication range between 12% to 30% even with HBO2 therapy, and around 25% of survivors may experience permanent neurological problems.

Barotrauma can also impact the inner ear, and while this usually gets better on its own, it can sometimes result in permanent damage. Another condition, known as nitrogen narcosis, also has a good prognosis as it completely resolves when the individual ascends to a higher altitude. However, the condition can impair judgment and potentially lead to drowning.

Preventing Dysbarism

Certain health conditions can make diving dangerous. These include lung conditions like spontaneous pneumothorax (a collapsed lung), problems with asthma, lung diseases that cause cavities or blockages, seizures, a particular type of heart defect called atrial septal defect, coronary artery disease, a chronically punctured eardrum, an inability to balance the pressure in the sinus or middle ear, or having gas trapped within the eye sockets.

Divers can prevent barotrauma (pressure-related injury) to the middle ear. To do so, they should avoid diving if they have a significant nasal congestion. While diving, they should descend with their feet first, go down slowly using an anchor line, and avoid forcefully holding their breath, especially when they are deep underwater or coming back to the surface.

If divers find it difficult to naturally balance the ear pressure, they can perform specific techniques to open the Eustachian tube (tube that connects the middle ear to the upper throat) and allow the free flow of gases. These techniques might include forcefully exhaling with the nose closed (Valsalva), yawning, swallowing, wiggling the jaw, or other specialized methods.

Taking medicines like pseudoephedrine or nasal steroids before diving can help reduce the chance of pressure-related ear injury.

When divers use a particular mixture of gases (helium and oxygen), including hydrogen or nitrogen can lessen the effects of a condition known as high-pressure neurological syndrome (HPNS). This syndrome is a result of the effects of breathing gases under high pressure. To avoid HPNS, divers should not dive to depths more than 500 feet and they should descend slowly or take breaks to adjust the body to the increasing pressure.

Frequently asked questions

Dysbarism refers to any harmful medical condition caused by changes in the surrounding pressure.

Less than 1% of divers develop Decompression Sickness (DCS).

Signs and symptoms of dysbarism, which refers to medical issues related to diving, can vary depending on the specific condition. However, some common signs and symptoms include: 1. Joint pain: Dysbarism can cause pain and discomfort in the joints, particularly in the limbs and back. This is often a result of decompression illness (DCI) affecting the joints and spinal cord. 2. Neurological abnormalities: In more severe cases of DCI, significant neurological abnormalities may be present. These can include paralysis, weakness, numbness, tingling, difficulty speaking or understanding speech, and changes in coordination or balance. 3. Lung and brain problems: Arterial gas embolism (AGE), a condition where air bubbles enter the bloodstream and block blood vessels, can lead to symptoms such as difficulty breathing, chest pain, coughing up blood, confusion, dizziness, seizures, and loss of consciousness. 4. Otic barotrauma: This refers to damage to the ears caused by changes in pressure during diving. Symptoms can include ear pain, hearing loss, ringing in the ears (tinnitus), dizziness, and fluid drainage from the ear. 5. Skin abnormalities: Dysbarism can also affect the skin, leading to symptoms such as itching, rash, swelling, and changes in skin color or texture. It's important to note that the signs and symptoms of dysbarism can vary in severity and may not always be immediately apparent. Some symptoms may develop shortly after diving, while others may take hours or even days to appear. Therefore, a thorough examination and detailed patient history are crucial in identifying and diagnosing dysbarism-related conditions.

Dysbarism can occur during underwater diving or when a person is exposed to intense pressure changes in settings such as high altitudes, aircraft cabin decompression, explosions or blasts, outer space, underwater construction sites, and tunnel operations.

The doctor needs to rule out the following conditions when diagnosing Dysbarism: - Narrowly avoiding drowning leading to a lack of oxygen to the brain - Injuries to the middle ear or sinus due to pressure changes - Infections of the sinus or ear - Injuries to the inner ear due to pressure changes - Poisoning by carbon monoxide or other harmful gases - Physical injuries to the muscles or skeleton - Low blood sugar, also known as hypoglycemia - Migraine headaches - Guillain-Barre syndrome, a rare neurological disorder - Multiple sclerosis, a disease affecting the nerves - Transverse myelitis, inflammation of the spinal cord - Compression of the spinal cord - Seizures - Stroke, which is caused by a disruption of blood supply to the brain - Heart attack, also known as myocardial infarction - Bleeding in the area surrounding the brain - Poisoning from seafood - Poisoning from an animal or insect sting - Side effects from certain medications, like mefloquine

The types of tests that may be ordered to properly diagnose dysbarism include: - Chest X-ray to rule out pneumothorax and assess for barotrauma or near drowning - Computed tomography (CT) or magnetic resonance imaging (MRI) scans to identify alternative causes of symptoms - Brain CT or MRI to check for air densities in small branches of arteries - Lab tests to measure blood cell concentration and levels of creatine phosphokinase, which may indicate arterial gas embolism (AGE) It is important to note that the diagnosis of decompression illness (DCI) is often confirmed based on the response to treatment rather than specific diagnostic tests.

The treatment for dysbarism depends on the specific condition. For decompression illness (DCI), treatment involves ensuring the patient's airways are open, providing 100% oxygen, and contacting a hyperbaric center for oxygen treatment under pressure. For tympanic membrane rupture, the treatment involves keeping the ear dry and allowing it to drain, with ear drops only used if an infection develops. Inner ear barotrauma is treated with rest and medications for dizziness, without the need for hyperbaric oxygen treatment unless there are signs of decompression sickness or gas embolism.

The prognosis for dysbarism, a condition caused by changes in pressure, varies depending on the specific condition within dysbarism. Here are the prognoses for some of the conditions included in dysbarism: - Barotrauma: The outlook for barotrauma is generally good as the condition often resolves itself. However, there can be serious complications, such as arterial gas embolism (AGE), which can be fatal if not treated properly with hyperbaric oxygen therapy (HBO2). Mortality rates for AGE range between 12% to 30% even with HBO2 therapy, and around 25% of survivors may experience permanent neurological problems. - Nitrogen narcosis: Nitrogen narcosis completely resolves when the individual ascends to a higher altitude. However, the condition can impair judgment and potentially lead to drowning. - Other conditions within dysbarism, such as decompression sickness and high-pressure neurological syndrome, are not mentioned in the text, so their prognosis is not provided.

An ear, nose, and throat specialist (otolaryngologist) should be consulted for Dysbarism.

Barotrauma Health