

Secondary analysis of a prospective, observational cohort. We aimed to assess the relationship between alveolar dead space fraction and mortality in a cohort of children meeting criteria for acute respiratory distress syndrome (both the Berlin 2012 and the American-European Consensus Conference 1994 acute lung injury) and pediatric acute respiratory distress syndrome (as defined by the Pediatric Acute Lung Injury Consensus Conference in 2015). Alveolar dead space fraction relies on the difference between arterial and end-tidal carbon dioxide (alveolar dead space fraction = (PaCO2 - PetCO2) / PaCO2).

Physiologic dead space is associated with mortality in acute respiratory distress syndrome, but its measurement is cumbersome.
