The purpose of this study was to evaluate blood lactate measurements and failure to noninvasive ventilation (NIV) in children admitted to a pediatric intensive care unit. This was a retrospective observational single-center study performed between June 2016 and June 2017. Dynamic lactate indices and failure to NIV in 63 children 1 month old were examined; we considered blood lactate analyses at time 0, 6, 24, and 48 hours. NIV failure group had a higher pediatric risk of mortality (PRISM) score. Lactate indices decreased over time in the success group (p