Department of Respiratory Care and Sleep Control Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
BMC Pulm Med. 2010 Mar 7;10:10. doi: 10.1186/1471-2466-10-10.
Health status, dyspnea and psychological status are important clinical outcomes in chronic obstructive pulmonary disease (COPD). However, forced expiratory volume in one second (FEV1) measured by spirometry, the standard measurement of airflow limitation, has only a weak relationship with these outcomes in COPD. Recently, in addition to spirometry, impulse oscillometry (IOS) measuring lung resistance (R) and reactance (X) is increasingly being used to assess pulmonary functional impairment.
We aimed to identify relationships between IOS measurements and patient-reported outcomes in 65 outpatients with stable COPD. We performed pulmonary function testing, IOS, high-resolution computed tomography (CT), and assessment of health status using the St. George's Respiratory Questionnaire (SGRQ), dyspnea using the Medical Research Council (MRC) scale and psychological status using the Hospital Anxiety and Depression Scale (HADS). We then investigated the relationships between these parameters. For the IOS measurements, we used lung resistance at 5 and 20 Hz (R5 and R20, respectively) and reactance at 5 Hz (X5). Because R5 and R20 are regarded as reflecting total and proximal airway resistance, respectively, the fall in resistance from R5 to R20 (R5-R20) was used as a surrogate for the resistance of peripheral airways. X5 was also considered to represent peripheral airway abnormalities.
R5-R20 and X5 were significantly correlated with the SGRQ and the MRC. These correlation coefficients were greater than when using other objective measurements of pulmonary function, R20 on the IOS and CT instead of R5-R20 and X5. Multiple regression analyses showed that R5-R20 or X5 most significantly accounted for the SGRQ and MRC scores.
IOS measurements, especially indices of peripheral airway function, are significantly correlated with health status and dyspnea in patients with COPD. Therefore, in addition to its simplicity and non-invasiveness, IOS may be a useful clinical tool not only for detecting pulmonary functional impairment, but also to some extent at least estimating the patient's quality of daily life and well-being.
健康状况、呼吸困难和心理状况是慢性阻塞性肺疾病（COPD）的重要临床结局。然而，通过肺活量计测量的一秒用力呼气量（FEV1），即气流受限的标准测量方法，与 COPD 患者的这些结果仅有较弱的相关性。最近，除了肺活量计之外，测量肺阻力（R）和电抗（X）的脉冲振荡法（IOS）也越来越多地被用于评估肺功能障碍。
我们旨在确定 65 名稳定期 COPD 门诊患者的 IOS 测量值与患者报告结果之间的关系。我们进行了肺功能测试、IOS、高分辨率计算机断层扫描（CT），并使用圣乔治呼吸问卷（SGRQ）评估健康状况，使用医学研究委员会（MRC）量表评估呼吸困难，使用医院焦虑和抑郁量表（HADS）评估心理状况。然后，我们研究了这些参数之间的关系。对于 IOS 测量值，我们使用 5Hz 和 20Hz 时的肺阻力（R5 和 R20）和 5Hz 时的电抗（X5）。因为 R5 和 R20 分别被认为反映了总气道和近端气道阻力，所以 R5 到 R20 的阻力下降（R5-R20）被用作外周气道阻力的替代物。X5 也被认为代表外周气道异常。
R5-R20 和 X5 与 SGRQ 和 MRC 显著相关。这些相关系数大于使用其他肺功能的客观测量值时的相关系数，例如 IOS 上的 R20 和 CT 而不是 R5-R20 和 X5。多元回归分析表明，R5-R20 或 X5 最能解释 SGRQ 和 MRC 评分。
IOS 测量值，特别是外周气道功能的指标，与 COPD 患者的健康状况和呼吸困难显著相关。因此，除了其简单性和非侵入性之外，IOS 可能不仅是一种有用的临床工具，不仅可以检测肺功能障碍，而且在某种程度上至少可以估计患者的日常生活质量和幸福感。
