Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Royal Brompton and Harefield Hospitals, Guys and St Thomas' Trust, London, United Kingdom.
J Appl Physiol (1985). 2023 Jul 1;135(1):205-216. doi: 10.1152/japplphysiol.00744.2022. Epub 2023 Jun 1.
This study explored the use of computed cardiopulmonography (CCP) to assess lung function in early-stage cystic fibrosis (CF). CCP has two components. The first is a particularly accurate technique for measuring gas exchange. The second is a computational cardiopulmonary model where patient-specific parameters can be estimated from the measurements of gas exchange. Twenty-five participants (14 healthy controls, 11 early-stage CF) were studied with CCP. They were also studied with a standard clinical protocol to measure the lung clearance index (LCI). Ventilation inhomogeneity, as quantified through CCP parameter σlnCl, was significantly greater ( < 0.005) in CF than in controls, and anatomical deadspace relative to predicted functional residual capacity (DS/FRCpred) was significantly more variable ( < 0.002). Participant-specific parameters were used with the CCP model to calculate idealized values for LCI (iLCI) where extrapulmonary influences on the LCI, such as breathing pattern, had all been standardized. Both LCI and iLCI distinguished clearly between CF and control participants. LCI values were mostly higher than iLCI values in a manner dependent on the participant's respiratory rate (r = 0.46, < 0.05). The within-participant reproducibility for iLCI appeared better than for LCI, but this did not reach statistical significance ( ratio = 2.2, = 0.056). Both a sensitivity analysis on iLCI and a regression analysis on LCI revealed that these depended primarily on an interactive term between CCP parameters of the form σlnCL*(DS/FRC). In conclusion, the LCI (or iLCI) probably reflects an amalgam of different underlying lung changes in early-stage CF that would require a multiparameter approach, such as potentially CCP, to resolve. Computed cardiopulmonography is a new technique comprising a highly accurate sensor for measuring respiratory gas exchange coupled with a cardiopulmonary model that is used to identify a set of patient-specific characteristics of the lung. Here, we show that this technique can improve on a standard clinical approach for lung function testing in cystic fibrosis. Most particularly, an approach incorporating multiple model parameters can potentially separate different aspects of pathological change in this disease.
本研究探讨了使用计算心肺图（CCP）评估早期囊性纤维化（CF）患者的肺功能。CCP 有两个组成部分。第一部分是一种特别准确的气体交换测量技术。第二部分是一个计算心肺模型，可以从气体交换的测量中估计患者特定的参数。25 名参与者（14 名健康对照者，11 名早期 CF 患者）接受了 CCP 研究。他们还接受了标准临床方案来测量肺清除指数（LCI）。通过 CCP 参数 σlnCl 量化的通气不均匀性在 CF 患者中明显大于（<0.005）对照组，并且解剖死腔与预测功能残气量（DS/FRCpred）的比值明显更可变（<0.002）。使用 CCP 模型和参与者特定的参数来计算 LCI 的理想值（iLCI），其中对 LCI 的肺外影响，例如呼吸模式，都已标准化。LCI 和 iLCI 都清楚地区分了 CF 和对照组参与者。LCI 值在很大程度上高于 iLCI 值，这与参与者的呼吸频率有关（r = 0.46，<0.05）。iLCI 的个体内可重复性似乎优于 LCI，但这并没有达到统计学意义（比值=2.2，=0.056）。对 iLCI 的敏感性分析和对 LCI 的回归分析都表明，这些主要取决于 CCP 参数的交互项 σlnCL*（DS/FRC）的形式。总之，LCI（或 iLCI）可能反映了早期 CF 中不同潜在肺部变化的混合体，需要一种多参数方法（如可能的 CCP）来解决。计算心肺图是一种新技术，它由一个用于测量呼吸气体交换的高精度传感器和一个心肺模型组成，用于识别一组患者特定的肺部特征。在这里，我们表明该技术可以改进 CF 患者的肺功能测试的标准临床方法。特别是，结合多个模型参数的方法可以潜在地分离出该疾病中不同的病理变化方面。
