Respiratory insufficiency syndrome (RIS) in preterm infants with gestational age of 32 weeks and less. Neonatal management and follow-up study.

The clinical entity of respiratory insufficiency syndrome (RIS), i.e. irregular breathing leading to recurrent apnea and bradycardia in an otherwise healthy preterm infant, has been studied in respect of symptomathology and management with intensive case including ventilatory support. During a 4-year period 26 of 103 infants with gestational age less than or equal to 32 weeks and mean weight 1304 g (range 710 to 1830 g) developed RIS. In most infants the initial apnea occurred after 2 and before 72 hours post delivery but in some infants later. Because of progressive hypoxemia and acidosis 15 of the 26 RIS infants required IPPV treatment. The 76% survival rate of RIS infants seems to justify intensive care with ventilatory support even in the smallest preterm infants with RIS, especially as the follow-up study performed at 15 months to 3-1/2 years of age showed neurological sequelae in only 3 of 20 surviving babies, i.e. 15% sequelae rate.