Respiratory distress

More than 2 of the following symptoms are recorded twice 15-30 Min. apart: respiratory rate > 60/min, cyanosis in room air, inspiratory retractions, expiratory grunting, nasal flaring).

• None: RDS has been lasting <3 h or if the infant has been intubated immediately after birth for prolonged apnea without respiratory effort.
• Meconium aspiration syndrome: clinical criteria (meconium stained amniotic fluid) AND x-ray criteria: coarse, linear peribronchial infiltrations radiating from the hilar areas to both lungs; low diaphragm (increased lung volume due to air-trapping)
• Infectious pneumopathy: clinical, radiological or histological evidence of infection as well as at least one microbiologically relevant positive culture of tracheal aspirate or blood
• Other or unknown cause: includes transient RDS lasting ≥ 2 hours (but not transient isolated tachypnea without other signs of is not RDS), wet lung syndrome, spontaneous pneumothorax, and hyaline membrane disease