- These neonates were diagnosed with RDS and supported by invasive ventilation with synchronized intermittent mandatory ventilation (SIMV. The diagnosis of RDS was based on clinical manifestations and chest X-ray findings. The clinical signs and symptoms of RDS were respiratory distress, tachypnea, nasal flaring, groan, and cyanosis after birth. The typical X-ray picture of RDS showed a grain shadow, air bronchogram or white lung;