What Is Respiratory Distress Syndrome?

Respiratory distress syndrome (RDS) is a breathing disorder that affects newborns. RDS rarely occurs in full-term infants. The disorder is more common in premature infants born about 6 weeks or more before their due dates.

RDS is more common in premature infants because their lungs aren't able to make enough surfactant (sur-FAK-tant). Surfactant is a liquid that coats the inside of the lungs. It helps keep them open so that infants can breathe in air once they're born.

Without surfactant, the lungs collapse and the infant has to work hard to breathe. He or she might not be able to breathe in enough oxygen to support the body's organs. The lack of oxygen may damage the infant's brain and other organs if proper treatment isn't given.

Most infants who develop RDS show signs of breathing problems and a lack of oxygen at birth or within the first few hours that follow.

Overview

RDS is one of the most common lung disorders in premature infants. It affects about 10 of every 100 premature babies in the United States. In fact, nearly all infants born before 28 weeks of pregnancy develop RDS.

RDS may be an early phase of bronchopulmonary dysplasia (brong-ko-PUL-mo-nar-e dis-PLA-ze-ah), or BPD. This is another breathing disorder that affects premature babies.

RDS usually develops in the first 24 hours after birth. If breathing problems are still present by the time premature infants reach their original due dates, they may be diagnosed with BPD. Some of the life-saving treatments used to treat RDS may cause BPD.

Some infants who have RDS recover and never get BPD. Infants who have RDS and get BPD have lungs that are less developed or more damaged than the infants who recover.

Infants who develop BPD usually have fewer healthy air sacs and tiny blood vessels in their lungs. Both the air sacs and the tiny blood vessels that support them are needed to breathe properly.

Outlook

Due to recent medical advances, most infants who have RDS and weigh more than 2 pounds (or about 1,000 grams) at birth now survive. However, these babies may need some extra medical care after going home.

Some babies develop complications from RDS or its treatments. Serious complications include chronic (ongoing) breathing problems, such as asthma and BPD; blindness; and brain damage.

Other Names for Respiratory Distress Syndrome

• Hyaline membrane disease
• Neonatal respiratory distress syndrome
• Infant respiratory distress syndrome
• Surfactant deficiency

What Causes Respiratory Distress Syndrome?

The main cause of respiratory distress syndrome (RDS) is a lack of surfactant in the lungs. Surfactant is a liquid that coats the inside of the lungs.

A fetus's lungs start making surfactant at around 26 to 34 weeks of pregnancy. The substance coats the insides of the air sacs in the lungs. This helps keep the lungs open so breathing can occur after birth.

Without enough surfactant, the lungs will likely collapse when the infant exhales (breathes out). The infant then has to work harder to breathe. He or she might not be able to get enough oxygen to support the body's organs.

Some full-term infants develop RDS because they have faulty genes that affect how their bodies make surfactant.

Who Is At Risk for Respiratory Distress Syndrome?

Certain factors may increase the risk that your infant will develop respiratory distress syndrome (RDS). These factors include:

• Premature delivery. The earlier your baby is born, the greater his or her risk for RDS. Most cases of RDS occur in babies born before 28 weeks of pregnancy.
• Stress during your baby's delivery, especially if you lose a lot of blood (hemorrhage).
• Infection.
• Your having diabetes.

Your baby also is at greater risk for RDS if you require an emergency cesarean delivery (C-section) before your baby is full term. You may need an emergency C-section because of a condition, such as a detached placenta, that puts you or your infant at risk.

Planned C-sections that occur before babies' lungs have fully matured also can increase the risk of RDS. Your doctor can do tests before delivery that can show whether it's likely that your baby's lungs are fully developed. These tests assess the age of the fetus or lung maturity.

What Are the Signs and Symptoms of Respiratory Distress Syndrome?

Signs and symptoms of respiratory distress syndrome (RDS) usually occur at birth or within the first few hours that follow. They include:

• Rapid, shallow breathing
• Sharp pulling in of the chest below and between the ribs with each breath
• Grunting sounds
• Flaring of the nostrils

The infant also may stop breathing for a few seconds every now and then. This condition is called apnea.

Respiratory Distress Syndrome Complications

Depending on the severity of an infant's RDS, he or she may develop other medical problems.

Lung Complications

Lung complications may include a collapsed lung (atelectasis), leakage of air from the lung into the chest cavity (pneumothorax), and bleeding in the lung (hemorrhage).

Some of the life-saving treatments used for RDS may cause bronchopulmonary dysplasia, another breathing disorder.

Blood and Blood Vessel Complications

Infants who have RDS may develop sepsis, an infection of the bloodstream. This infection can be life threatening.

Lack of oxygen may prevent a fetal blood vessel called the ductus arteriosus from closing after birth as it should. This condition is called patent ductus arteriosus, or PDA.

The ductus arteriosus connects a lung artery to a heart artery. If it remains open, it can put strain on the heart and increase blood pressure in the lung arteries.

Other Complications

Complications of RDS also may include blindness and other eye problems and a bowel disease called necrotizing enterocolitis (EN-ter-o-ko-LI-tis). Infants who have severe RDS can develop kidney failure.

Some infants who have RDS develop bleeding in the brain (intraventricular hemorrhage). This can delay mental development. It also can cause mental retardation or cerebral palsy.

How Is Respiratory Distress Syndrome Diagnosed?

Respiratory distress syndrome (RDS) is common in premature infants. Thus, doctors usually recognize and begin treating the disorder as soon as babies are born.

Doctors also do several tests to rule out other conditions that could be causing an infant's breathing problems. The tests also can confirm that the doctors have diagnosed the condition correctly.

The tests include:

• Chest x ray. A chest x ray takes pictures of the structures inside the chest, such as the heart and lungs. This test can show whether your infant has signs of RDS. A chest x ray also can detect problems, such as a collapsed lung, that may require urgent treatment.
• Blood tests. Blood tests are used to see whether an infant has enough oxygen in his or her blood. Blood tests also can help find out whether an infection is causing the infant's breathing problems.
• Echocardiography. This test uses sound waves to create a moving picture of the heart. Echocardiography is used to rule out heart defects as the cause of an infant's breathing problems.

How Is Respiratory Distress Syndrome Treated?

Treatment for respiratory distress syndrome (RDS) usually begins as soon as an infant is born, sometimes in the delivery room.

Most infants who show signs of RDS are quickly moved to a neonatal intensive care unit (NICU). There they receive around-the-clock treatment from health care professionals who specialize in treating premature infants.

The most important treatments for RDS are:

• Surfactant replacement therapy.
• Breathing support from a ventilator or nasal continuous positive airway pressure (NCPAP). These machines help premature infants breathe better.
• Oxygen therapy.

Surfactant Replacement Therapy

Surfactant is a liquid that coats the inside of the lungs. It helps keep them open so that an infant can breathe in air once he or she is born.

Infants who have RDS are given surfactant until their lungs have developed enough to start making their own surfactant. Surfactant usually is given through a breathing tube that's attached to a bag to help push the surfactant directly into the baby's lungs.

Once the surfactant is given, the breathing tube is connected to a ventilator, or the baby may get breathing support from NCPAP.

Surfactant often is given right after birth in the delivery room to try to prevent or treat RDS. It may be given several times over the next few days, until the baby is able to breathe better.

Some women are given medicines called corticosteroids during pregnancy. These medicines can speed up surfactant production and lung development in a fetus. Even if you had these medicines, your infant may still need surfactant replacement therapy after birth.

Breathing Support

Infants who have RDS often need breathing support until their lungs start making enough surfactant. Until recently, a mechanical ventilator usually was used. The ventilator was connected to a breathing tube that ran through the infant's mouth or nose into the windpipe.

Today, more and more infants are receiving breathing support from an NCPAP machine. NCPAP gently pushes air into the baby's lungs through prongs placed in the infant's nostrils.

Oxygen Therapy

Infants who have breathing problems may get oxygen therapy. Oxygen may be given through the ventilator or NCPAP machine, or through a tube in the nose. Oxygen therapy is given to make sure that the infants' brains, hearts, livers, and kidneys get enough oxygen to work properly.

Other Treatments

Other treatments for RDS include medicines, supportive therapy, and treatment for patent ductus arteriosus (PDA). PDA is a condition that affects some premature infants.

Medicines

Doctors often give antibiotics to infants who have RDS to control infections (if the doctors suspect that an infant has an infection).

Supportive Therapy

Treatment in the NICU is designed to limit stress on babies and meet their basic needs of warmth, nutrition, and protection. Such treatment usually includes:

• Using a radiant warmer or incubator to keep infants warm and reduce the chances of infection.
• Ongoing monitoring of blood pressure, heart rate, breathing, and temperature through sensors taped to the babies' bodies.
• Using sensors on fingers or toes to check the amount of oxygen in the infants' blood.
• Giving fluids and nutrients through needles or tubes inserted into the infants' veins. This helps prevent malnutrition and promotes growth. Nutrition is critical to the growth and development of the lungs. Later, babies may be given breast milk or infant formula through feeding tubes that are passed through their noses or mouths and into their throats.
• Checking fluid intake to make sure that fluid doesn't build up in the babies' lungs.

Treatment for Patent Ductus Arteriosus

PDA is a possible complication of RDS. In this condition, a fetal blood vessel called the ductus arteriosus doesn't close after birth as it should.

The ductus arteriosus connects a lung artery to a heart artery. If it remains open, it can put strain on the heart and increase blood pressure in the lung arteries.

PDA is treated with medicines, catheter procedures, and surgery. For more information, go to “How Is Patent Ductus Arteriosus Treated?”

How Can Respiratory Distress Syndrome Be Prevented?

You can take steps to help ensure that your infant isn't born before his or her lungs have developed completely. These steps include:

• Seeing your doctor regularly during your pregnancy
• Following a healthy diet
• Avoiding tobacco smoke, alcohol, and illegal drugs
• Controlling any ongoing medical conditions you have
• Preventing infection

If you're having a planned cesarean delivery (C-section), your doctor can do tests before delivery to show whether it's likely that your baby's lungs are fully developed. These tests assess the age of the fetus or lung maturity.

Your doctor may give you injections of a corticosteroid medicine if he or she thinks you may give birth too early. This medicine can speed up surfactant production and development of the lungs, brain, and kidneys in your baby.

Usually, within about 24 hours of your taking the medicine, the baby's lungs start making enough surfactant. This will reduce the infant's risk for respiratory distress syndrome (RDS). If the baby does develop RDS, it will probably be relatively mild.

If you start taking the corticosteroid medicine at least 15 hours before you deliver, it also can reduce the chances that your baby will have any bleeding in the brain.

Living With Respiratory Distress Syndrome

Caring for a premature infant can be challenging. You may experience:

• Emotional distress, including feelings of guilt, anger, and depression.
• Anxiety about your baby's future.
• A feeling of a lack of control over the situation.
• Financial stress.
• Problems relating to your baby while he or she is in the neonatal intensive care unit (NICU).
• Fatigue (tiredness).
• Frustration that you can't breastfeed your infant right away. (You can pump and store your breast milk for later use.)

Take Steps to Manage Your Situation

You can take steps to help yourself during this difficult time. For example, take care of your health so that you have enough energy to deal with the situation.

Learn as much as you can about what goes on in the NICU. You can help your baby during his or her stay there and begin to bond with the baby before he or she comes home.

Learn as much as you can about your infant's condition and what's involved in daily care. This will allow you to ask questions and feel more confident about your ability to care for your baby at home.

Seek out support from family, friends, and hospital staff. Ask the case manager or social worker at the hospital about what you'll need after your baby leaves the hospital. The doctors and nurses can assist with questions about your infant's care. Also, you may want to ask whether your community has a support group for parents of premature infants.

Parents are encouraged to visit their baby in the NICU as much as possible. Spend time talking to your baby and holding and touching him or her (when allowed).

Ongoing Care for Your Infant

Your baby may need special care after leaving the NICU, including:

• Special hearing and eye exams
• Speech or physical therapy
• Specialty care for other medical problems caused by premature birth

Talk to your child's doctor about ongoing care for your infant and any other medical concerns you have.

Key Points

• Respiratory distress syndrome (RDS) is a breathing disorder that affects newborns. RDS rarely occurs in full-term infants. The disorder is more common in premature infants born about 6 weeks or more before their due dates.
• RDS is one of the most common lung disorders in premature infants. It affects about 10 out of every 100 premature babies in the United States. In fact, nearly all infants born before 28 weeks of pregnancy develop RDS.
• RDS may be an early phase of bonchopulmonary dysplasia (BPD), another breathing disorder that affects premature infants. However, some infants who have RDS recover and never develop BPD.
• The main cause of RDS is a lack of surfactant in the lungs. Surfactant is a liquid that coats the inside of the lungs and helps keep them open. Premature infants' lungs aren't able to make enough surfactant.
• Certain factors may increase the risk that your infant will develop RDS. These factors include premature delivery, stress during delivery, infection, and if you have diabetes. Your baby also is at greater risk if you have an emergency cesarean delivery (C-section). Planned C-sections that occur before babies' lungs have fully matured also can increase the risk of RDS.
• You can take steps to help ensure that your infant isn't born before his or her lungs have developed completely. See your doctor regularly during your pregnancy. Follow a healthy diet and avoid tobacco smoke, alcohol, and illegal drugs. Control any ongoing medical conditions you have, and try to prevent infections.
• Signs and symptoms of RDS usually occur at birth or within the first few hours that follow. They include rapid, shallow breathing; sharp pulling in of the chest below and between the ribs with each breath; grunting sounds; and flaring of the nostrils. The infant also may stop breathing for a few seconds every now and then.
• Depending on the severity of an infant's RDS, he or she may develop other medical problems, such as lung, blood, or blood vessel complications.
• RDS is common in premature infants. Thus, doctors usually recognize and begin treating the disorder as soon as babies are born. Doctors also do several tests to rule out other conditions that could be causing an infant's breathing problems and to confirm a diagnosis.
• Most infants who show signs of RDS are quickly moved to a neonatal intensive care unit. There they receive around-the-clock care from health professionals who specialize in treating premature infants.
• Treatments for RDS include surfactant replacement therapy, breathing support, oxygen therapy, medicines, supportive therapy, and other treatments.
• Caring for a premature infant can be challenging. You may experience a range of emotions. You can take steps to help yourself during this difficult time. Take care of your health so that you have enough energy to deal with the situation. Learn as much as you can about your infant's condition and what's involved in daily care. Seek out support from family, friends, and hospital staff.
• Due to recent medical advances, most infants who have RDS and weigh more than 2 pounds (or about 1,000 grams) at birth now survive. However, these infants may need some extra medical care after going home from the hospital.

Links to Other Information About Respiratory Distress Syndrome

NHLBI Resources

• Bronchopulmonary Dysplasia (Diseases and Conditions Index)
• Lung Information for the Public
• Ventilator/Ventilator Support (Diseases and Conditions Index)

Non-NHLBI Resources

• Respiratory Distress Syndrome (MedlinePlus)

Clinical Trials

• Current Research (ClinicalTrials.gov)
• NHLBI Pediatric Clinical Trials
• Patient Recruitment for Studies Conducted by the NHLBI, NIH