Diseases & Conditions

Acute Respiratory Distress Syndrome - Adult Respiratory Distress Syndrome

Overview, Causes, & Risk Factors

Adult respiratory distress syndrome, which is also called ARDS, is a breakdown in the function of the lungs that comes on suddenly. With this condition, there is severe inflammation in the lungs. This inflammation 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
  • burns
  • 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, such as cardiopulmonary bypass
  • severe trauma to other parts of the body
  • severe trauma to the lungs, such as from a crush injury to the chest

  • Symptoms & Signs

    What are the signs and symptoms of the disease?

    Symptoms of ARDS can vary, depending on the cause, but they usually develop within 1 to 3 days after a trauma or infection damages the lungs. Shortness of breath occurs first, followed in most cases by rapid, shallow breathing. Other symptoms may include:

  • anxiety and restlessness
  • cognitive impairment, which means having a hard time thinking
  • discoloration of the skin, including cyanosis, which is a bluish color in the skin, even with oxygen therapy
  • decreased urination
  • muscle weakness
  • noisy breathing
  • rapid heartbeat

  • Diagnosis & Tests

    How is the disease diagnosed?

    After doing a complete medical history and physical exam, the doctor may suspect ARDS. This is especially true when shortness of breath develops in a person who has had severe trauma or infection. Tests the doctor may order 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, called CBC, to check for 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

  • Prevention & Expectations

    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 can't be prevented.

    What are the long-term effects of the disease?

    Four out of ten people who have ARDS will die from it, even with treatment. But the other 60 percent will survive, if they receive the right treatment. 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 catching. If it is caused by an infection such as pneumonia, the infection may be contagious.

    Treatment & Monitoring

    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, which is an 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 poses a risk of infection, bleeding, or allergic reaction to anesthesia.

    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 doctor.


    Author:Eileen McLaughlin, RN, BSN
    Date Written:
    Editor:Crist, Gayle P., MS, BA
    Edit Date:07/28/02
    Reviewer:Kathleen A. MacNaughton, RN, BSN
    Date Reviewed:10/07/02



    Harrison's Principle of Internal Medicine, Fauci, 1998

    Professional Guide to Diseases, Brian Burlew, et al, 1995