Surfactant Protein D Is Associated With Severe Pediatric ARDS, Prolonged Ventilation, and Death in Children With Acute Respiratory Failure

Abstract

Elevated surfactant protein D (SP-D) is a relatively specific indicator of lung injury and is associated with both acute and chronic lung disease in adults and respiratory distress syndrome in premature infants. The relationship between plasma SP-D and lung injury in children with acute respiratory failure is unclear. Is plasma SP-D associated with lung injury or outcome in children with acute respiratory failure? This was a prospective cohort study in children 2weeks to 17 years of age with acute respiratory failure who participated in the BALI multi-center study. Analyses were done using SP-D levels in plasma from the first sample taken on either the day of intubation or one of the following 2days. SP-D level was measured by enzyme-linked immunosorbent assay. Plasma samples from 350 patients were used in the analysis; 233 had pediatric ARDS (PARDS). SP-D levels varied across primary diagnoses (P< .001). Elevated SP-D levels were associated with severe PARDS after adjusting for age, pediatric risk of mortality III (PRISM-III), and primary diagnosis (OR= 1.02; CI= 1.01-1.04; P= .011). Multivariable analyses also indicated that elevated SP-D levels were associated with death (OR= 1.02; CI= 1.01-1.04; P= .004), duration of mechanical ventilation (P= .012), PICU length of stay (P= .019), and highest oxygenation index (P= .040). SP-D levels also correlated with age (rs= 0.16, P= .002). Elevated plasma SP-D levels are associated with severe PARDS and poor outcomes in children with acute respiratory failure. Future studies will determine whether SP-D can be used to predict the degree of lung injury or response to treatment and whether SP-D is useful in identifying PARDS endotypes.