The data generated by this study regarding safety, comparison of nb-BAL and TA, and cytokine concentrations will be used as preliminary data informing the design of a larger multicenter study testing the hypothesis that IL-10 and IL-12p70 levels in airway secretions can predict risk for ARDS in this population. This may be approached via application to the Pediatric Acute Lung Injury and Sepsis (PALISI) clinical research network group.