Chokes

What is Chokes?

“Chokes” is a term used by divers to refer to a deadly lung-related form of decompression sickness (DCS). This health issue can happen when deep-sea divers rise to the surface too fast or do not follow the correct procedures to decompress. Key symptoms include having trouble breathing, feeling pain in the chest, and coughing. It’s important to note that these symptoms can also be caused by more common conditions like asthma and acute coronary syndrome (ACS), which is a medical term for a heart attack. As a result, doctors can easily miss this rare diagnosis and may not provide the right treatment on time.

Here’s what occurs when a diver is under deep water: high pressure from nitrogen gas balances out inside the diver’s body tissues. When the diver ascends, which means moving upwards towards the surface, the pressure from the nitrogen around the body lessens. If the diver ascends slowly, their body tissues can gradually adjust to the surrounding pressure and slowly release the nitrogen gas. But if the diver ascends quickly, nitrogen is released from their tissues rapidly, forming bubbles. These gas bubbles can block small and large blood vessels, irritate the airways, and disrupt the exchange of gases in the lungs. The end result of these changes is DCS.

The bubbles blocking blood vessels can occur in various parts of the body. From 85% to 90% of people with DCS feel pain in the joints of their legs or arms, a condition casually known as “bends”. About 5% to 10% show neurological symptoms like feeling dizzy, becoming paralyzed, or losing consciousness. Around 2% experience “chokes”, where the bubbles from nitrogen block the arteries in the lungs, causing severe fluid buildup in the lungs, known as pulmonary edema.

What Causes Chokes?

Pulmonary decompression sickness (DCS) happens when bubbles of nitrogen gas form quickly in your blood or lung tissue. This happens after a quick drop in the pressure around your body. This is commonly seen in people who rise too fast from deep-sea diving. These bubbles can block the blood vessels in your lungs, which affects the exchange of oxygen and carbon dioxide.

This blockage can lead to inflammation in the lining of your blood vessels and cause fluid to collect in your lungs – a condition known as pulmonary edema. If these symptoms aren’t recognized and treated quickly, there can be severe complications, including heart and lung failure, which may even lead to death.

Factors that increase your chances of getting pulmonary DCS include rising too fast from a deep dive, absorbing too much nitrogen during a dive, doing deep or long dives, repeating dives without enough time on the surface to allow your body to get rid of the nitrogen, and individual characteristics that affect how your body absorbs and gets rid of gases.

Risk Factors and Frequency for Chokes

DCS, or decompression sickness, in divers isn’t very common, with only 0.01% to 0.095% of divers affected based on the surroundings and the type of diving. As Vann et al found out, DCS affecting the lungs makes up to 5.6% of all DCS cases and is the first obvious condition in 0.9% of those cases.

• More recent information from the Divers Alert Network shows that 1.4% of DCS cases from 2014 to 2017 affected the lungs.
• In 2018, out of 624 DCS cases reported, just 4 were of DCS affecting the lungs.

Signs and Symptoms of Chokes

Divers with pulmonary decompression sickness (DCS) tend to have spent a lot of time deep underwater without following the correct decompression procedures. People with this condition usually start to notice symptoms from a few minutes to a few hours after coming back up to the surface. These symptoms can include chest pain, coughing, and shortness of breath, similar to the symptoms of a blood clot in the lungs.

Initially, these divers appear to be stable, but they may also have symptoms related to their inner ear, such as feeling dizzy, losing their hearing or a ringing in their ears. Other signs of the condition can include pain in the torso or pelvis, a skin rash that looks like marble, coughing up blood, and pain and swelling in the joints and extremities.

Pulmonary DCS is rare in people who fly high-performance aircraft. If such a person, especially a military pilot, shows symptoms of pulmonary DCS after being at a high altitude, they should be thoroughly checked by a healthcare provider. If needed, they may be treated with hyperbaric oxygen therapy.

The individual’s vital signs may initially appear normal, but they may start to have a faster than normal breathing rate, heart rate, and lower than normal level of oxygen in the blood within minutes. If the chest is listened to, crackling sounds might be heard. If the person already had a lung-related problem, a wheezing sound might be heard too. If the breath sounds reduced, this could mean the person has a collapsed lung. Crepitus (crackling) in the neck or over the sternum (breastbone) may suggest air in the mediastinum (the area in the chest between the lungs).

If the abdomen is tender and distended, this may mean that there is gas in the blood vessels in the mesentery (tissue in the abdomen) and the portal (liver) vessels. People with pulmonary DCS may also show signs of skin mottling, joint tenderness, joint swelling, rapid, involuntary movements of the eyes, and poor coordination.

Nearly half of individuals with pulmonary DCS develop symptoms within the first hour after decompression too rapidly. The remaining get sick a few hours after the offending event. Despite getting the right treatment, people with this condition can get worse quickly due to fluid accumulation in the lungs, breathing failure, a problem with the right side of the heart, and collapse of the cardiovascular system.

Testing for Chokes

If you experience sudden difficulties breathing, chest pain, and persistent cough within a few hours after an event that involves quick changes in pressure (like scuba diving), you might be experiencing a condition called acute pulmonary Decompression Sickness (DCS). The diagnosis of this condition is often made based on these symptoms.

To confirm the diagnosis, your doctor may order imaging tests, which typically include a chest X-ray, a CT scan of your abdomen, or an MRI scan of your brain and spine. The chest X-ray might show general signs of infiltrates (an abnormal substance in the air sacs of the lungs) scattered in both lungs. If your lung has collapsed (a condition referred to as pneumothorax), an X-ray will show a dark region around it. A CT scan can show the presence of gas in your portal and mesenteric blood vessels, which are vessels that supply your digestive organs. It can also show any signs of a tear in your gastrointestinal tract. An MRI scan of your spine and brain can reveal initial swelling, followed by changes due to lack of blood supply or damage to a particular area.

Your doctor might also request a blood test to analyze your blood gases. In the early stages of acute pulmonary DCS, this test will typically show low levels of oxygen in your blood, without an increase in carbon dioxide levels. If the levels of both oxygen and carbon dioxide in your blood are altered, it may indicate that your lung functions are deteriorating. If the condition is affecting other organs in your body, you may also have increased levels of various substances such as liver enzymes, C-reactive protein, creatinine kinase, creatine, lactate dehydrogenase, and pancreatic amylase in your blood.

Treatment Options for Chokes

When a person shows signs of lung-related decompression sickness (pulmonary DCS), the immediate medical response is crucial. Pre-hospital care involves making sure the person can breathe properly while conducting a quick, focused check-up. It’s important that the person’s heart rate and oxygen levels are constantly monitored during this assessment and while being transferred to the hospital.

Once at the emergency room, the person will be provided with as much oxygen as they can take in. This is done to help ensure they have enough oxygen in their blood and body, and to help remove any extra gas that may have formed in the lungs due to decompression sickness. A tube may be inserted into a vein for giving fluids and medication. If the person’s condition worsens during treatment, the medical team will be ready to provide life-saving procedures. These could involve providing both basic and advanced cardiac life support – techniques used to help keep the heart pumping and maintain blood circulation.

As soon as their condition is stable, the person will be moved to a hyperbaric chamber – this is a pressure chamber where the air pressure is higher than sea level pressure. If the person was taken to a hospital that does not have this facility, they’ll need to be transferred to a hospital that does. This specialized treatment is the best way to treat lung-related decompression sickness.

Inside the hyperbaric chamber, a treatment plan like the one recommended by the U.S. Navy will be followed. If other complications arise that affect other body systems, the person may be sent to see other specialist doctors.

What else can Chokes be?

When someone is having symptoms such as severe shortness of breath, chest pain, and coughing, a lot of different conditions need to be considered. These might include:

• Myocardial infarction (heart attack)
• Water inhalation (breathing in water)
• Gas contamination in the lungs
• Pulmonary oxygen toxicity (too much oxygen in the lungs, this is usually not common in diving)
• Pulmonary embolus (a clot in the lungs)
• Alkaline aspiration, i.e., breathing in water that has leaked into a diving rebreather
• Pulmonary congestion (fluid build-up in the lungs)
• Aortic dissection (a severe condition affecting the main artery of the body)
• Esophageal perforation (a tear in the tube connecting the throat and stomach)

In more extreme cases, doctors should also look out for signs of conditions such as anaphylaxis (a severe allergic reaction), drowning, and severe asthma attacks.

What to expect with Chokes

The outlook for patients diagnosed with pulmonary DCS (decompression sickness involving the lungs) varies and depends on several factors like quickness of treatment, overall health, and the level of tissue damage. Generally, if mild-to-moderate pulmonary DCS is quickly diagnosed and treated, the outcome is typically good.

However, severe cases could lead to long-lasting lung and systemic complications, particularly if treatment is not promptly started.

Preventing the disease is very important in reducing the risk of getting pulmonary DCS. Teaching patients about safe diving practices and when they should seek medical help can significantly increase their chances of successfully managing the condition.

Possible Complications When Diagnosed with Chokes

If decompression sickness (DCS) affecting the lungs isn’t promptly treated, it may result in different complications. The lungs could get permanently damaged leading to the formation of scar tissues, reduced lung capacity, and consistent low oxygen levels in the blood. The nervous system could also get damaged, leading to temporary or permanent issues based on how long the low oxygen lasted. System-wide inflammation and lack of adequate blood supply could result in heart failure, inflammation of the pancreas, liver failure, kidney problems, arthritis, and stomach ulcers.

Possible complications:

• Permanent lung damage (fibrosis)
• Reduced lung capacity (decreased tidal volume)
• Consistent low oxygen levels in the blood (chronic hypoxemia)
• Temporary or permanent neurological damage
• Heart failure
• Pancreatitis (inflammation of the pancreas)
• Liver failure
• Renal impairment (kidney problems)
• Arthritis (joint inflammation)
• Gastrointestinal ulcers (stomach ulcers)

Preventing Chokes

The prevention of lung-related illnesses from scuba diving begins by educating divers about safe diving habits. These include following the correct steps to decompress at the end of a dive, diving only within the range of your training, and ensuring enough time has passed between multiple dives. The broader community’s role is also vital. For instance, companies that provide diving experiences should regularly check and maintain their equipment to ensure divers aren’t forced to come up too quickly. They may also want to have their clients undergo a medical check-up before participating.

Healthcare professionals should thoroughly check divers to make sure they are fit enough for diving. They should stress the importance of good nutrition, staying hydrated, getting enough sleep, and staying in shape between dives. People new to diving should always be told to go with an experienced diver at all times.