The lungs are like sponges that absorb oxygen, making breathing possible. You’re probably familiar with drowning, and even though you may not have experienced it before, you may have seen a drowning scene in the movies. When water enters the lungs, it can be oppressive and difficult to breathe. This feeling is comparable to the symptoms of a condition called Acute Respiratory Distress Syndrome (ARDS).
In acute respiratory distress syndrome (ARDS), the lungs swell and fill with fluid, blocking oxygen from being exchanged. Regardless of age or health, anyone can develop this syndrome; it doesn’t just happen to the elderly or those with underlying health conditions. It is really more prevalent than most people think, with up to 200,000 instances recorded annually in the US alone.
Normal Lung Function and Gas Exchange
When air enters healthy lungs, it passes through the trachea, which is your wing pipe, and into the lungs. There are microscopic air sacs called alveoli, that make up the lungs. Breathing causes these alveoli to expand and collapse. Oxygen in the air enters these sacs through capillaries, which are microscopic blood vessels. At the same time, carbon dioxide leaves circulation and enters the air sacs for exhalation. We call this process gas exchange.
The Inflammatory Response in ARDS
The root cause of ARDS is typically an infection, injury, or illness. The body reacts to any of these by activating the immune system. The immune system tries to fight off injury or infection by releasing substances. This reaction causes the lungs to be inflamed and swell. Although swelling is a natural defense mechanism, in ARDS it becomes uncontrollable and damages the lungs.
Damage to the Alveolar Capillary Membrane
The alveolar capillary membrane, a vital part of the lung, becomes damaged once the inflammation that comes with ARDS begins. The lungs’ capillaries and alveoli are separated by this thin membrane. The membrane is what allows carbon dioxide to flow in the opposite direction and oxygen to flow from the alveoli into the bloodstream. If this membrane is damaged, it makes it more difficult for carbon dioxide to exit the blood and oxygen to enter the blood.
Because the alveolar capillary membrane has been destroyed, there is little to no oxygen in the blood, a condition known as hypoxemia. Hypoxemia can make it difficult for organs and tissues throughout the body to receive the oxygen they need, which leads to issues such as confusion, weakness, and so on.
However, ARDS affects more than just the lungs. It can also have an impact on other parts of the body. When oxygen levels in the blood drop, the heart works harder to pump blood and provide oxygen to the organs. This can put strain on the heart, resulting in conditions such as low blood pressure. Other organs, such as the kidney and liver, may be unable to operate correctly because they, too, require oxygen.
Symptoms of Acute Respiratory Distress Syndrome (ARDS)
- Severe shortness of breath
- Rapid breathing
- Low oxygen levels
- Extreme tiredness
- Confusion
- Dizziness
- Coughing
- Chest discomfort
Causes of Acute Respiratory Distress Syndrome (ARDS)
Direct lung injuries: These are problems that directly affect the lungs. Aspiration, trauma, and pneumonia are a few of these problems. Pneumonia is a severe lung infection that causes fluid to fill the alveoli, making breathing difficult.
Contrarily, aspiration is an unintentional injury that irritates and inflames the lungs when food, drink, or stomach contents enter the lungs rather than the stomach.
On the other hand, trauma, such as getting hit in the chest during a car accident, can cause immediate lung damage and ARDS.
Indirect lung injuries: These injuries start outside of the lungs and spread there due to problems in other parts of the body. Indirect lung injuries that could result in acute respiratory distress syndrome include severe pancreatitis, sepsis, and major operations. There are some infections that are localized, and others that affect the entire body. The condition that affects the entire body is called sepsis, which can cause inflammation in the lungs and other parts of the body. Again, the inflammation is as a result of the body’s attempt to fight the infection.
Conversely, severe pancreatitis leads to inflammation of the pancreas, which can cause toxic substances to be released into the blood. Because of these toxic substances, the lung can get inflamed.
Lung problems can happen during major surgeries, particularly those performed on the chest or heart, either as a result of the body’s inflammatory reaction or because the oxygen during the procedure was limited.
Other possible causes: Aside from being injured directly or indirectly, diseases such as coronavirus can seriously damage the lungs, causing inflammation and fluid to build up in the lungs. This can lead to a severe case of ARDS. Also, breathing in harmful substances like smoke, toxic gasses, or chemicals can also damage the lungs and make them inflamed.
Summary
No matter how healthy you are, anyone can get ARDS. It can be brought on by serious infections (like pneumonia), chest injuries from accidents, or other illnesses like sepsis. ARDS may happen from even inhaling dangerous substances like smoke or toxic gasses.
