TY - JOUR T1 - Double tracer gas single breath washout – Comparison with conventional lung function tests in children with and without cystic fibrosis JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p2024 AU - Florian Singer AU - Chiara Abbas AU - Georgette Stern AU - Elisabeth Kieninger AU - Oliver Fuchs AU - Nicolas Regamey AU - Per Gustafsson AU - Carmen Casaulta AU - Urs Frey AU - Philipp Latzin Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p2024.abstract N2 - A tidal single breath washout (SBW) has been shown to have potential as new lung function test. We calculated indices describing the shape of the SBW curve, and investigated their variability and association with conventional lung function tests in cystic fibrosis (CF) and healthy children.70 CF children, mean (SD) age 11.7 (3.5) years, and 42 healthy children aged 11.5 (3.9) years performed nitrogen multiple breath washout (MBW) and helium and sulfur hexafluoride SBW using a side-stream ultrasonic flowmeter (Eco Medics AG). 8 CF children and 10 controls performed MBW and SBW on a second day. Molar mass (MM) SBW curves were plotted vs. expired volume. MM-slopes of tidal phase II and III (MM_SII; MM_SIII), and area under the MM curve (AUC) were calculated. Mean (SD) between-test coefficient of variation (CV%) for MM_SIII, MM_SII, and AUC was 15.5 (13.3)%, 15.3 (11.4)%, and 8.7 (6.5)%, respectively. All three CV% were similar between CF and healthy children. MM_SIII was associated with expired tidal volume (TV) and mean tidal flow (MTEF), and MM_SII with TV. MM_SIII and MM_SII differed significantly between CF and healthy children. MM_SIII and MM_SII were associated with the lung clearance index (p<0.001 for both) but not with spirometry indices. AUC was not associated with lung function test parameters.We identified double tracer gas SBW indices reliably characterizing ventilation inhomogeneity (VI) and separating healthy from CF children despite considerable overlap. More detailed analyses are needed to better understand underlying pathophysiological phenomena and to obtain additional yet unknown information on VI from this test. ER -