Title: TRACHEAL ASPIRATE (TA) LECITHIN SPHINGOMYELIN RATIO (L/S) AND RECOVERY FROM RDS
Abstract: Previously we have demonstrated that changing TA L/S were associated with survival from RDS. In this current report L/S of serial TA obtained during the first 120 hrs. of life were examined in 30 infants with severe RDS requiring endotracheal intubation. The infants were divided into two groups by survival: survivors (S), n=19; non-survivors (NS), n=ll. The means of all L/S values per day in infants with at least three samples per 24 hr. period were calculated. In S 10/14 (71%), 10/12 (83%) and 9/9 (100%) infants had mean L/S > 2.5 on days 3, 4 and 5 respectively. In NS 1/5 (20%), 1/6 (17%) and 1/7 (14%) infants had mean L/S > 2.5 on days 3, 4 and 5 respectively. This difference was significant by day 4 (p < 0.05). Both S and NS were similar in their requirement for ventilatory support at 48 and 72 hrs. of life. At 96 and 120 hrs. there were significantly fewer S requiring mechanical ventilation. Thus, the attainment of a TA L/S > 2.5 by day 4 appears to be a chemical predictor of survival in infants with severe RDS. A significant observation in this study was that the attainment of a TA L/S > 2.5 on day 4 was independent of gestational age. This observation suggests that TA L/S is related to postnatal factors.