Adult Respiratory Distress Syndrome
- acute respiratory distress syndrome
Adult respiratory distress syndrome, abbreviated as ARDS, is a breakdown in the function of the lungs that comes on suddenly. With this condition, there is severe inflammation in the lungs which reduces the lungs' ability to take up oxygen. It may cause lung or respiratory failure. Although called "adult," ARDS can also occur in children.
What is going on in the body?
ARDS is usually brought on by some other serious condition in the body, such as trauma or infection, that directly or indirectly injures the lung. When a person has ARDS, the lungs and tiny blood vessels around the lungs become inflamed and swollen. This inflammation interferes with the lungs' ability to function properly. The lungs have a hard time getting oxygen into the bloodstream and removing carbon dioxide from the blood. As inflammation increases, fluid can leak from the blood vessels into the lungs. As fluid builds up and inflammation increases, the lungs become stiff and may completely fail to work. .
What are the causes and risks of the disease?
More than 30 percent of people who have sepsis
, which is a life-threatening infection of the bloodstream, will develop ARDS. Some of the other causes of ARDS are:
- blood transfusions of large amounts of blood
- drug overdose
- infection of the lungs, such as bacterial or viral pneumonia
- inhaling large amounts of smoke
- inhaling toxic fumes, such as those from chlorine or ammonia
- inhaling the contents of the stomach, known as aspiration pneumonia
- near drowning
- serious inflammation in other parts of the body, such as acute pancreatitis
- prolonged or severe shock
- surgery in which the person has been placed on cardiopulmonary bypass (a heart-lung machine)
- severe trauma to other parts of the body
- severe trauma to the lungs, such as from a crush injury to the chest
What can be done to prevent the disease?
Prevention of ARDS depends on the cause. Avoiding exposure to infection may prevent some cases that are caused by infection. Avoiding smoking, drugs, and alcohol may decrease the risk of lung problems in general. Seeking prompt treatment for illnesses may also decrease the risk of ARDS. Many cases cannot be prevented.
How is the disease diagnosed?
After doing a complete medical history and physical exam, the healthcare professional may suspect ARDS. This is especially true when shortness of breath develops in a person who has had severe trauma or infection.
Other tests that may be helpful include:
arterial blood gases, to measure the level of oxygen in the blood
chest X-ray to visualize the structure and integrity of the lungs
a complete blood count (CBC), to check for evidence of infection
culture of any fluid that has been drained from the lungs, to check for infection
pulmonary artery catheterization, which is a special X-ray test that looks at blood flow and blood pressure in the lungs
pulmonary function tests, which measure lung capacity and other vital functions
- various tissue and blood cultures to check for the source of an infection
Long Term Effects
What are the long-term effects of the disease?
Four out of ten people who have ARDS will die from it, even with appropriate treatment.. Of the rest, those who respond quickly to treatment often have no long-term effects. But those who needed to stay on a ventilator for a long time to treat their ARDS may have ongoing lung problems, including infections
Other long-term effects are related to the cause of ARDS. For example, pneumonia can permanently damage the lungs and even cause death.
What are the risks to others?
ARDS itself is not contagious. However, if it is caused by an infection such as pneumonia, the infection may be contagious.
What are the treatments for the disease?
People with ARDS must be treated in a hospital, often in the intensive care unit. Keeping the person's oxygen intake within healthy limits is key, as well as treating the underlying cause of the lung injury. It is also crucial to maintain the person's fluid balance. Either too much or too little fluid can be harmful and will affect the outcome of ARDS.
Treatment may also include:
- antibiotics to treat infections or sepsis
- surgery, if an injury caused the ARDS
- use of a ventilator (artificial breathing machine)
Research is also promising for several other treatments, including replacement surfactant and anti-inflammatory agents, but more study is needed.
What are the side effects of the treatments?
Side effects depend on the treatments used. For example, antibiotics can cause stomach upset, allergic reaction, and other effects. Surgery can be complicated by infection, bleeding, or an allergic reaction to anesthetic.
What happens after treatment for the disease?
In many cases, no further measures are needed after treatment of ARDS, and the person is able to return to his or her usual activities. Often, however, a person will have to battle ongoing lung problems. He or she may need physical therapy and pulmonary therapy to strengthen the body and the lungs.
How is the disease monitored?
Arterial blood gases and chest X-rays will be done repeatedly until the person improves. Any new or worsening symptoms should be reported to the healthcare professional.
Harrison's Principle of Internal Medicine, Fauci, 1998
Professional Guide to Diseases, Brian Burlew, et al, 1995