Renal function in idiopathic respiratory distress syndrome.

Renal function was studied in 11 pre-term infants with idiopathic respiratory distress syndrome (IRDS) grade 1 according to Prod'hom's criteria. As a reference 16 healthy pre-term infants were studied. The groups did not differ with regard to mean gestational age (GA) and mean postnatal age (PNA). The studies were prefomred twice, first at a PNA of 33--37 hours and then at 132--148 hours. GFR and CPAH were determined with the single injection technique and the ability to excrete Na+ was determined following an oral Na+ load. GFR was higher in IRDS infants at the first investigation and slightly lower in IRDS infants at the second investigation. The GFR correlated to the lowest recorded PaO2 (r=0.45) in IRDS infants. CPAH was similar in IRDS and controls at the first, and lower in IRDS infants at the second investigation. The urinary Na+ excretion was significantly higher in IRDS infants. Treatment with digitalis was in part responsible for the high urinary Na+ excretion. The IRDS infants had a higher Na+ and glucose intake than the control infants. It is suggested that this higher intake is in part responsible for the relatively high GFR and urinary Na+ excretion in IRDS infants.