Respiratory distress syndrome (RDS) in infants; Infant respiratory distress syndrome (IRDS); Neonatal respiratory distress syndrome; RDS - infants
Respiratory distress syndrome is one of the most common lung disorders in premature infants and causes increasing difficulty in breathing. See also ARDS (acute respiratory distress syndrome).
Causes, incidence, and risk factors
Respiratory distress syndrome affects 10% of all premature infants and only rarely affects those born at full-term. The disease is caused by a lack of lung surfactant, a chemical that normally appears in mature lungs. Surfactant keeps the air sacs from collapsing and allows them to inflate with air more easily.
In respiratory distress syndrome, the air sacs collapse and prevent the child from breathing properly. Symptoms usually appear shortly after birth and become progressively more severe.
Risk factors are prematurity, diabetes in the mother, and stress during delivery that produces acidosis in the newborn at birth.
- Rapid breathing
- Unusual breathing movement - drawing back of the chest muscles with breathing (see intercostal retractions)
- Shortness of breath and grunting sounds while breathing
- Nasal flaring
- Breathing stops briefly
- Bluish color of the skin and mucus membranes
- Arms or legs puffy or swollen
Signs and tests
- A blood gas analysis shows low oxygen and acidosis.
- A chest x-ray indicates respiratory distress (the lungs develop a characteristic “ground glass” appearance).
- Lung function studies may be necessary.
- Blood cultures and a sepsis work-up are usually done to rule out infection and sepsis as a cause of the respiratory distress.
High-risk and premature infants require prompt attention by a pediatric resuscitation team.
First, the infant is given high oxygen and humidity concentrations. Infants with mild symptoms are given supplemental oxygen. Those with severe symptoms are managed on a ventilator to deliver both oxygen and pressure to keep the lungs inflated.
Oxygen and pressure will be reduced as soon as possible to prevent side effects associated with too much oxygen or pressure.
An artificial lung surfactant is sometimes delivered through an endotracheal tube into the lungs of an infant at high risk for respiratory distress syndrome immediately after birth. Studies find that this treatment can prevent or improve the course of respiratory distress syndrome. Enough research has been done on surfactants to show that they reduce death from IRDS.
The condition may persist or worsen for 2 to 4 days after birth with improvement thereafter. Some infants with severe respiratory distress syndrome will die.
Long-term complications may develop as a result of oxygen toxicity, high pressures delivered to the lungs, the severity of the condition itself, or periods when the brain or other organs did not receive enough oxygen.
- Bronchopulmonary dysplasia
- Hemorrhage into the brain (intraventricular bleed)
- Hemorrhage into the lung (sometimes associated with surfactant use)
- Thrombotic events associated with an umbilical arterial catheter
- Retrolental fibroplasia and blindness
- Delayed mental development and mental retardation associated with anoxic brain damage or hemorrhage
Calling your health care provider
This disorder usually develops shortly after birth while the baby is still in the hospital. If you have given birth at home or outside a medical center, seek emergency attention if your baby develops any difficulty breathing.
Since IRDS is one of many conditions that usually occur in a premature infant, every effort is usually made to help mothers carry babies to term. Ideally, this effort begins with the first prenatal visit, which should be scheduled as soon as a mother discovers that she is pregnant. Good prenatal care results in larger, healthier babies and fewer premature births.
If a mother does goes into labor prematurely, every effort is made to stop the labor and allow the pregnancy to continue to full term. A lab test called the L/S ratio (a measurement of the fetus’s lung maturity) is made and labor is usually halted until the L/S ratio shows that the lungs have matured. The infant’s chances of not developing IRDS, if not 100%, are at least improved.
When it appears that premature delivery is unavoidable, administration of corticosteroids to the mother 2 to 3 days prior to delivery may help the fetal lung tissue mature in certain cases.
by Mamikon Bozoyan, M.D.