Bozier Jack, Jeagal Edward, Robinson Paul D, Prisk G Kim, Chapman David G, King Gregory G, Thamrin Cindy, Rutting Sandra
Woolcock Institute of Medical Research, The University of Sydney, Glebe, NSW, Australia.
Dept of Respiratory Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.
ERJ Open Res. 2022 Jul 18;8(3). doi: 10.1183/23120541.00614-2021. eCollection 2022 Jul.
The multiple breath nitrogen washout (MBNW) test provides important clinical information in obstructive airways diseases. Recently, a significant cross-sensitivity error in the O and CO sensors of a widely used commercial MBNW device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) was detected, which leads to overestimation of N concentrations. Significant errors in functional residual capacity (FRC) and lung clearance index (LCI) have been reported in infants and children. This study investigated the impact in adults, and on additional important indices reflecting conductive ( ) and acinar ( ) ventilation heterogeneity, in health and disease.
Existing MBNW measurements of 27 healthy volunteers, 20 participants with asthma and 16 smokers were reanalysed using SPIROWARE V 3.3.1, which incorporates an error correction algorithm. Uncorrected and corrected indices were compared using paired t-tests and Bland-Altman plots.
Correction of the sensor error significantly lowered FRC (mean difference 9%) and LCI (8-10%) across all three groups. was higher following correction (11%, 14% and 36% in health, asthma and smokers, respectively) with significant proportional bias. was significantly lower following correction in the asthma and smoker groups, but the effect was small (2-5%) and with no proportional bias.
The O and CO cross-sensitivity sensor error significantly overestimated FRC and LCI in adults, consistent with data in infants and children. There was a high degree of underestimation of but minimal impact on . The presence of significant proportional bias indicates that previous studies will require reanalysis to confirm previous findings and to allow comparability with future studies.
多次呼气氮洗脱（MBNW）试验为阻塞性气道疾病提供了重要的临床信息。最近，在一种广泛使用的商用MBNW设备（Exhalyzer D，Eco Medics AG，瑞士迪尔滕）的O和CO传感器中检测到显著的交叉敏感性误差，这导致氮浓度被高估。在婴儿和儿童中，已报告功能残气量（FRC）和肺清除指数（LCI）存在显著误差。本研究调查了该误差对成年人的影响，以及对反映传导性（ ）和腺泡性（ ）通气异质性的其他重要指标在健康和疾病状态下的影响。
使用包含误差校正算法的SPIROWARE V 3.3.1对27名健康志愿者、20名哮喘患者和16名吸烟者现有的MBNW测量数据进行重新分析。使用配对t检验和Bland-Altman图比较未校正和校正后的指标。
校正传感器误差后，所有三组的FRC（平均差异9%）和LCI（8 - 10%）均显著降低。校正后 更高（健康组、哮喘组和吸烟者分别为11%、14%和36%），存在显著的比例偏差。哮喘组和吸烟者组校正后 显著降低，但影响较小（2 - 5%）且无比例偏差。
O和CO交叉敏感性传感器误差在成年人中显著高估了FRC和LCI，这与婴儿和儿童的数据一致。 存在高度低估，但对 的影响最小。显著比例偏差的存在表明，之前的研究需要重新分析，以确认之前的发现，并便于与未来的研究进行比较。
