Double tracer gas single-breath washout: reproducibility in healthy subjects and COPD

作者：Husemann Kim^*; Berg Nina; Engel Jennifer; Port Johannes; Joppek Christoph; Tao Ziran; Singer Florian; Schulz Holger; Kohlhaeufl Martin

来源：European Respiratory Journal, 2014, 44(5): 1210-1222.

DOI：10.1183/09031936.00085713

The applicability and interpretation of inert tracer gas washout tests is hampered by the lack of feasible protocols and reproducibility data. We assessed feasibility, variability and reproducibility of a new easy to perform double tracer gas (DTG) single-breath washout (SBW) test and compared this with conventional nitrogen washouts. %26lt;br%26gt;In 40 healthy nonsmokers and 20 patients with stable chronic obstructive pulmonary disease (COPD), we performed three N-2 vital capacity SBWs, three N-2 multiple-breath washouts and three tidal DTG-SBW tests. Follow-up was after 1 week, 1 month and 6 months. Main outcomes were the lung clearance index (LCI) (N-2 multiple-breath washout), slope of phase III (dN(2)) (N-2 vital capacity SBW) and slope of phase III (SIIIDTG) (DTG-SBW). %26lt;br%26gt;In healthy subjects, mean +/- SD LCI at baseline was 6.94 +/- 0.61, dN(2) 0.99 +/- 0.42% N-2 per litre and SIIIDTG -0.206 +/- 0.108 g.mol(-1).L-1. In COPD, LCI and dN(2) were significantly higher (LCI 12.23 +/- 2.67, dN(2) 7.43 +/- 5.38% N-2 per litre; p%26lt;0.001) and SIIIDTG significantly steeper (-0.653 +/- 0.428 g.mol(-1).L-1:1, p%26lt;0.001). Reproducibility was high for main outcome parameters: the intraclass correlation coefficient over 6 months was 0.77 (0.86 in COPD) for LCI, 0.82 (0.89) for dN(2) and 0.83 (0.93) for SIIIDTG. %26lt;br%26gt;The tidal DTG-SBW is a reproducible test in healthy and COPD subjects that seems attractive for use in routine clinical settings.

• 出版日期2014-11