Mortality in premature infants treated with exogenous surfactant

Abstract

Objective: Characterize mortality and associated factors in Chilean prematures born < 32 weeks of gestational age (GA) and treated with exogenous surfactant. 

Method: Cohort of newborns (n = 2 868) registered between 1998-2005 in the database of the Surfactant National Program. The association of gestational and neonatal variables with mortality was estimated through survival analysis and logistic regression. 

Results: Global mortality was 35%, varying by GA from 86.7% (< 25 weeks) to 12.6% (32 weeks). There was a clear decrease of mortality during the study period, along with a fall in the gestational age and birth weight (BW) of the patients who died (1 021 g ± 295 to 854 g ± 258) and GA (27.7 ± 2.1 to 26.5 ± 23) during this period. Pulmonary hemorrhage (PH) was the most important factor associated to mortality, so we decided to stratify the analysis by this condition. In children with PH, the mortality estimated risk lower as the GA increased (OR= 0.73; CI95 0.57-0.93) and every 100 g of additional BW (OR= 0.74; CI95 0.63-0.88). Children not affected by PH also had their OR diminished with major GA (OR= 0.82; CI95 0.76-0.90) and more BW (OR= 0.84; CI95 0.79 - 0.89). In addition, the OR decreased with better Apgar 5 min score (OR= 0.80; CI95 0.75-0.85), use of prenatal corticoids (OR= 0.71; CI95 0.56-0.90) and was higher in boys (OR= 1.36; CI95 1.08-1.71). 

Conclusions: Mortality in premature newborns decreased 15% during this period. Inmaturity and extreme low birth weight factors constitute a challenge to improve survival and avoid further complications like PH.