Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Graduate School for Health Sciences, University of Bern, Bern, Switzerland.
Physiol Meas. 2024 Nov 14;45(11). doi: 10.1088/1361-6579/ad8da4.
Sulfur hexafluoride (SF) multiple-breath washout (MBW) assesses ventilation inhomogeneity, as an early marker of obstructive respiratory diseases. Primary outcomes are customarily washout-derived, and it is unclear whether the preceding SF-washin can provide similar estimates. We aimed to assess comparability of primary SF-MBW outcomes between washin and washout phases of infant SF-MBW data measured with the WBreath (ndd Medizintechnik AG, Zurich, Switzerland) and Spiroware (Eco Medics AG, Duernten, Switzerland) MBW-setups, respectively.We assessed mean relative differences in lung clearance index (LCI) and functional residual capacity (FRC) between the washin and washout of existing SF-MBW data from healthy infants and infants with cystic fibrosis (CF). We assessed whether these differences exceeded the mean relative within-test between-trial differences of washout-derived outcomes, which can be attributed to natural variability. We also explored non-physiological factors using a pediatric lung simulator.LCI and FRC from washin and washout were not comparable, for both setups. The mean difference (SD) in LCI between washin and washout was 2.3(10.8)% for WBreath and -9.7(8.0)% for Spiroware, while in FRC it was -4.7(8.4)% for WBreath and -2.3(9.7)% for Spiroware. These differences exceeded the within-test between-trial differences in washout-derived outcomes. Outcomes from washin and washout were also not comparable in a pediatric lung simulator.Outcomes of the washin and washout were not comparable due to an interplay of physiological and non-physiological factors, and cannot be used interchangeably.
六氟化硫（SF）多次呼吸冲洗（MBW）评估通气不均匀性，作为阻塞性呼吸道疾病的早期标志物。主要结果通常是冲洗衍生的，尚不清楚前面的 SF 冲洗是否可以提供类似的估计。我们旨在评估使用 WBreath（ndd Medizintechnik AG，苏黎世，瑞士）和 Spiroware（Eco Medics AG，Duernten，瑞士）MBW 设备分别测量的婴儿 SF-MBW 数据的冲洗和冲洗阶段的主要 SF-MBW 结果之间的可比性。我们评估了健康婴儿和囊性纤维化（CF）婴儿的现有 SF-MBW 数据的冲洗和冲洗之间肺清除指数（LCI）和功能残气量（FRC）的平均相对差异。我们评估了这些差异是否超过了冲洗衍生结果的平均相对试验内试验间差异，这归因于自然变异性。我们还使用儿科肺模拟器探索了非生理因素。对于两种设备，冲洗和冲洗的 LCI 和 FRC 均不可比。WBreath 的冲洗和冲洗之间 LCI 的平均差异（SD）为 2.3（10.8）％，Spiroware 为-9.7（8.0）％，而 FRC 的冲洗和冲洗之间的平均差异（SD）为 WBreath 为-4.7（8.4）％，Spiroware 为-2.3（9.7）％。这些差异超过了冲洗衍生结果的试验内试验间差异。儿科肺模拟器中的冲洗和冲洗结果也不可比。由于生理和非生理因素的相互作用，冲洗和冲洗的结果不可比，因此不能互换使用。
