[Incidence and etiologic factors of persistent ductus arteriosus in relation to the severity of idiopathic respiratory distress syndrome].

Out of 332 patients with a confirmed diagnosis of RDS, 214 were mechanically ventilated more than 48 hours and 118 less than 48 hours. The incidence of a hemodynamically active persistent ductus arteriosus (PDA) revealed a significant difference for both groups. (54% versus 4,2%). The distribution of PDA did not seem to correlate with birthweight but rather with the severity of RDS, defined by the duration of artificial ventilation. Between three selected groups of 214 patients with longterm ventilation (1. RDS-PDA with surgical ligation - 2. RDS-PDA with spontaneous closure - 3. RDS without PDA) we found significant differences only in the values of inspiratory pressures on mechanical ventilation. No significant differences were found in the time of exposure to high levels of oxygen, the fluid balance, and the application of furosemide.