Improved agreement between N₂ and SF₆ multiple-breath washout in healthy infants and toddlers with improved EXHALYZER D sensor performance

Modern nitrogen multiple-breath washout (N 2 MBW) systems such as EXHALYZER D use O 2 and CO 2 sensors to calculate N 2 concentrations. New corrections for interactions between high O 2 and CO 2 concentrations on the gas sensors now provide accurate N 2 signals. The correct N 2 signal led to much improved agreement between N 2 MBW and sulfur hexafluoride (SF 6 ) MBW functional residual capacity (FRC) and lung clearance index (LCI) in 52 sleeping healthy infants and toddlers, suggesting a role for N 2 MBW in this age-group.