New timesaving predictor-algorithm for Multiple Breath Wash-out in Adolescents

BACKGROUND: Multiple Breath Wash-out (MBW) is an informative but time consuming test. This study evaluates the uncertainty of a time saving predictor algorithm in adolescents.

METHODS: Adolescents were recruited from the Copenhagen Prospective Study on Asthma in Childhood (COPSAC2000) birth cohort. MBW trials were performed at age 13 years with Innocor model Inn00400 using sulfur hexafluoride (SF6) as tracer gas. Measurements were analyzed using a mixed model focusing on two prediction points doubling (t5%) and quadrupling (t10%) the standard end-point (t2.5%).

RESULTS: One-hundred-seventy-two MBW trials conducted in 78 adolescents with and without asthma from COPSAC2000 were included. At t10% the wash-out time was reduced by 41% and an uncertainty of 0.159 Lung Clearance Index (LCI) units was introduced (±2 standard deviations (SD)), ±1.27). At t5% the wash-out time was reduced by 25%, with an uncertainty of 0.083 LCI-units (±0.558). The optimal prediction point, which led to most time saved and least uncertainty was t5%.

CONCLUSION: The predictor algorithm is capable of shortening the MBW test time, but introduces an increasing uncertainty with earlier prediction points. This first-of-a-kind prediction algorithm holds promise in shortening the MBW test in children, but should be used with caution in subjects with normal LCI values.Pediatric Research (2016); doi:10.1038/pr.2016.57.