Risk Factors

    • Prematurity

    • Male

    • Hypothermia

    • Maternal diabetes

    • Cesarian

    • Perinatal asphyxia

    • Multiple pregnancy

    • FHx of RDS

Differential diagnosis


    • Affects about 1% of newborn infants and is the leading cause of death in preterm infants

    • Incidence decreases with advancing gestational age

      • About 50% in babies born at 26–28 weeks

      • About 25% at 30–31 weeks

      • > 90% at 28 weeks?

      • 50% at 32 weeks?

    • More frequent in infants of diabetic mothers and in the second born of premature twins


    • Surfactant deficiency

    • => full lung closure on expiration

Clinical features

  • tachypnea

  • tachycardia

    • chest wall retractions (recession)

    • expiratory grunting

    • breath against a partially closed glottis

    • flaring of the nostrils

    • cyanosis

    • Progression over 2-3 days

      • More O2 required

      • Either => death or recovery by 72 h


    • Deficit in surfactant

      • Complex system of lipids, proteins and glycoproteins

      • Produced in specialized lung cells called Type II cells or Type II pneumocytes

      • Packaged by the cell in structures called lamellar bodies, and extruded into the air-spaces

        • Unfold into a complex lining of the air-space

      • Reduces the surface tension of the fluid that lines the air-space

        • Surface tension is responsible for approximately 2/3 of the elastic recoil forces

      • Prevents the air-spaces from completely collapsing on exhalation

      • Allows re-opening of the air-space with a lower amount of force

    • Without adequate amounts of surfactant, the air-spaces collapse and are very difficult to expand

    • Lungs are characterized by collapsed air-spaces alternating with hyper-expanded areas, vascular congestion and, in time, hyaline membranes.

    • As a result, blood passing through the lungs is unable to pick up oxygen and unload carbon dioxide

    • Structural immaturity, as manifest by decreased number of gas-exchange units and thicker walls, also contributes to the disease process

    • Therapeutic oxygen and positive-pressure ventilation, while potentially life-saving, can also damage the lung


    • Fetal lung maturity may be tested by sampling the amount of surfactant in the amniotic fluid, obtained by inserting a needle through the mother's abdomen and uterus

    • Blood gases

      • respiratory and metabolic acidosis along with hypoxia

    • CXR

    • Pulmonary mechanics testing (PMT)

      • Reduced complience



a) conservative

b) medical

    • Pre-term glucocorticoids speed the production of surfactant

    • Ventilation

      • High frequency oscillatory ventilation

      • Continuous positive airway pressure (CPAP)

      • High-speed mechanical ventilation (> 40 breaths per min)

    • Oxygen

    • Intravenous fluids to stabilize the blood sugar, blood salts, and blood pressure

    • Extracorporeal membrane oxygenation (ECMO)

      • Not appropriate for premature babies

    • Exogenous surfactant

      • Pig better than synthetic

c) surgical