Predicting respiratory distress by thin-layer chromatography of the newborn gastric aspirate.

The analysis of gastric fluid from newborns for lecithin/sphingomyelin (L/S) ratio evaluation is useful in determining whether respiratory distress will follow an early delivery. Without exception, the L/S ratios obtained on 14 gastric aspirates paralleled and were slightly higher than intrapartum values obtained from corresponding amniotic fluids (5.6 vs 3.7). Of 46 normal infants, only 1 had a gastric aspirate L/S ratio less than 2:1. No false positive results were found. The obstetrician can easily obtain gastric fluid at delivery, and by ordering an L/S ratio determination, the neonatologist can have an estimation of lung surfactant levels within 2 hours after birth. In cases where true respiratory distress syndrome (RDS) must be differentiated from other problems of respiratory distress, this information can assist in the early management of patients with RDS. Even after the development of RDS, the procedure offers a prognostic tool which the clinician can use in discussing the outcome with the parents.