Hyaline membrane disease

Definition

Respiratory distress syndrome is one of the most common lung disorders in premature infants. The condition makes it hard to breathe.

See also: ARDS (acute respiratory distress syndrome).

Alternative Names

Causes

Respiratory distress syndrome affects 10% of all premature infants. It rarely affects those born full-term.

The disease occurs when the lungs lack a chemical that helps them inflate with air and keeps the air sacs from collapsing. This chemical, called lung surfactant, normally appears in mature lungs.

The lack of this chemical causes the air sacs to collapse and prevents the child from breathing properly. Symptoms usually appear shortly after birth and slowly become more severe.

Risk factors are prematurity, diabetes in the mother, and delivery complications that lead to acidosis

Symptoms

• 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

Exams 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.

Treatment

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 need a breathing machine to deliver oxygen as well as pressure, which keeps the lungs inflated.

Oxygen and pressure will be reduced as soon as possible to prevent side effects associated with too much oxygen or pressure.

For infants born before 30 weeks of age, an artificial lung surfactant is sometimes delivered through a tube placed into their lungs. This treatment is given only to older babies if the oxygen level drops below a certain level and the doctors believe RDS is present.

Outlook (Prognosis)

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.

Possible Complications

• Pneumothorax
• Pneumomediastinum
• Pneumopericardium
• 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

When to Contact a Medical Professional

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.

Prevention

Since infant respiratory distress syndrome (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 early, 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 done, and labor is usually halted until this test shows that the baby's lungs have matured. This decreases an infant's chances of developing IRDS.

When it appears that premature delivery is unavoidable, the mother will be given corticosteroids 2 to 3 days prior to delivery. In some cases, this may help the baby's lungs mature.