Acute Respiratory Distress Syndrome

ARDS, or acute respiratory distress syndrome, is a lung condition that leads to low oxygen levels in the blood. ARDS can be life threatening. This is because your body's organs, such as the kidneys and brain, need oxygen-rich blood to work properly.

ARDS usually occurs in people who are very ill with another disease or who have major injuries. Most people are already in the hospital when they develop ARDS.

What Causes ARDS?

Many conditions or factors can directly or indirectly injure the lungs and lead to ARDS. Some common ones are:

• Sepsis. This is a condition in which bacteria infect the bloodstream.
• Pneumonia. This is an infection in the lungs.
• Severe bleeding due to an injury to the body.
• An injury to the chest or head, like a severe blow.
• Breathing in harmful fumes or smoke.
• Inhaling vomited stomach contents from the mouth.

It's not clear why some very sick or seriously injured people develop ARDS and others don't. Researchers are trying to find out why ARDS develops and how to prevent it.

Who Is At Risk for ARDS?

People at risk for ARDS have a condition or illness that can directly or indirectly injure their lungs.

Direct Lung Injury

Conditions that can directly injure the lungs include:

• Pneumonia. This is an infection in the lungs.
• Breathing in harmful fumes or smoke.
• Inhaling vomited stomach contents from the mouth.
• Severe acute respiratory syndrome (SARS). This is a type of pneumonia.
• Using a ventilator. This is a machine that helps people breathe, but, rarely, it can injure the lungs.
• Nearly drowning.

Indirect Lung Injury

Conditions that can indirectly injure the lungs include:

• Sepsis. This is a condition in which bacteria infect the bloodstream.
• Severe bleeding due to an injury to the body or having many blood transfusion.
• An injury to the chest or head, like a severe blow.
• Pancreatitis (PAN-kre-a-TI-tis). This is a condition in which the pancreas becomes irritated or infected. The pancreas is a gland that releases enzymes and hormones.
• Fat embolism (EM-bo-lizm). This is a condition in which fat blocks an artery. A physical injury, like a broken bone, can lead to a fat embolism.
• Drug overdose.

What Are the Signs and Symptoms of ARDS?

The first signs and symptoms of ARDS are feeling like you can't get enough air into your lungs, rapid breathing, and low oxygen levels in the blood.

Other signs and symptoms depend on the cause of the condition. They may occur before ARDS develops. For example, if pneumonia is causing ARDS, you may have a cough and fever before you feel short of breath.

Sometimes, people with ARDS develop signs and symptoms such as low blood pressure, confusion, and extreme tiredness. This may mean that the body's organs, such as the kidneys and heart, aren't getting enough oxygen-rich blood.

Most people who develop ARDS are in the hospital for another serious health problem. Rarely, people who aren't hospitalized have health problems (such as severe pneumonia) that lead to ARDS.

How Is ARDS Treated?

ARDS is treated with oxygen, fluids, and medicines. Treatments are done in a hospital's intensive care unit.

The main goals of treating ARDS are to get oxygen to your lungs and organs (like the brain and kidneys) and treat the underlying condition that's causing ARDS.

Oxygen

First, your doctor will try to give you extra oxygen through soft, plastic prongs that fit into your nose, or through a mask that fits over your mouth (or mouth and nose).

If your oxygen level doesn't increase or it's still hard for you to breathe, your doctor will give you oxygen through a breathing tube. The flexible tube will be inserted through your mouth or nose and into your windpipe.

Before inserting the tube, your doctor will squirt or spray a liquid medicine into your throat (and possibly your nose) to make it numb. This helps prevent coughing and gagging when the tube is inserted. Your doctor also will give you medicine, through an intravenous (IV) line into your bloodstream, to make you sleepy and relaxed.

The breathing tube will be connected to a machine that helps you breathe (a ventilator). The ventilator will fill your lungs with oxygen-rich air.

Your doctor will adjust the ventilator often to help your lungs get the right amount of oxygen. This also will help prevent any further injury to your lungs from the pressure of the ventilator.

The breathing tube and ventilator are used until you can breathe on your own. If you need a ventilator for more than a few days, your doctor may do a tracheotomy (tra-ke-OT-o-me). This involves making a small cut in your neck to create an opening to the windpipe. Your doctor will place the breathing tube directly into the windpipe. The tube is then connected to the ventilator.

Fluids

Fluids may be given to improve the flow of blood through your body and to provide nutrition. Your doctor will make sure you get the right amount of fluids.

Too much fluid can fill the lungs, making it harder to get the oxygen you need. Not enough fluid can limit blood and oxygen flow to the body's organs. Fluids usually are given through an IV line inserted in one of your blood vessels.

Medicines

Your doctor may give you medicines to prevent and treat infections and to relieve discomfort.

Complications From ARDS

If you have ARDS, you can develop other medical problems while in the hospital. The most common are infections, pneumothorax (noo-mo-THOR-aks; collapsed lung), lung scarring, and blood clots.

• Infections. Being in the hospital and lying down for a long time can make you prone to infections, such as pneumonia. Being on a ventilator also can put you at higher risk for infections. Infections can be treated with antibiotics.
• Pneumothorax. This is a condition in which air or gas collects in the space around the lungs, which can cause one or both lungs to collapse. The pressure of the air from a ventilator can cause this condition. Your doctor will put a tube into your chest to remove the air and let your lung(s) expand again.
• Lung scarring. ARDS causes the lungs to become stiff (scarred) and makes it hard for them to expand and fill with air. Being on a ventilator also can cause lung scarring. Often, lung scarring heals before you leave the hospital.
• Blood clots. Lying down for long periods can cause blood clots to form in your body. A blood clot that forms in a vein deep in your body is called a deep vein thrombosis. This type of blood clot can break off, travel through the bloodstream to the lungs, and block blood flow. This is called pulmonary embolism.