Boros Piotr W, Franczuk Monika, Wesolowski Stefan
Lung Function Lab, National Tuberculosis and Lung Diseases Research Institute, Warsaw, Poland.
Respiration. 2004 Jul-Aug;71(4):374-9. doi: 10.1159/000079642.
Restriction is a typical functional abnormality in interstitial lung disease (ILD) patients, but is not always present, especially in the early stage of the disease. The greater reduction of vital capacity (VC; %pred.) than total lung capacity (TLC; %pred.) is regarded as a typical pattern of lung function disturbances in ILD patients.
To explore the diagnostic value of spirometry in a detection restrictive pattern the relative volume loss assessed by TLC and VC in large series of patients with a diagnosis of ILD referred for lung function tests was evaluated.
Retrospective, cross-sectional analysis of pulmonary function data was done. The sampleconsisted of 1,173 patients with the diagnosis of different interstitial lung diseases investigated during a period of 5 years. Only patients without airway obstruction (normal FEV1%VC) were included. In all cases spirometry and whole body plethysmography were performed by experienced staff using MasterLab - 'Jaeger' equipment according to ERS standards. Reference values according to ERS guidelines were applied.
The mean value of TLC expressed as %pred. was significantly (p < 0.001) lower than VC in all patients (93.7 +/- 18.6 vs. 98.0 +/- 21.4%pred.). The frequency of abnormal (lowered) TLC results was also higher than lowered VC (22.8 vs. 17.8%). Sensitivity of VC reached 69.3% and the positive predictive value was 88.5% in detecting volume restriction as compared to TLC measurement.
The relative loss of TLC was greater than VC in our large group of patients. Measurement of TLC should be part of functional assessment of ILD patients, irrespective of whether they present or do not present a restrictive pattern in spirometry.
限制性通气功能障碍是间质性肺疾病（ILD）患者典型的功能异常，但并非总是存在，尤其是在疾病早期。肺活量（VC；预计值百分比）较肺总量（TLC；预计值百分比）下降更明显被认为是ILD患者肺功能障碍的典型模式。
探讨肺量计在检测限制性模式中的诊断价值，评估在大量因肺功能检查而转诊的确诊ILD患者中，通过TLC和VC评估的相对容积损失。
对肺功能数据进行回顾性横断面分析。样本包括在5年期间调查的1173例诊断为不同间质性肺疾病的患者。仅纳入无气道阻塞（FEV1%VC正常）的患者。在所有病例中，由经验丰富的工作人员使用MasterLab - “耶格”设备按照ERS标准进行肺量计检查和全身体积描记法检查。应用ERS指南的参考值。
所有患者中，以预计值百分比表示的TLC平均值显著低于VC（93.7±18.6对98.0±21.4%预计值，p<0.001）。TLC结果异常（降低）的频率也高于VC降低的频率（22.8对17.8%）。与TLC测量相比，VC检测容积限制的敏感性达到69.3%，阳性预测值为88.5%。
在我们的大样本患者中，TLC的相对损失大于VC。TLC的测量应成为ILD患者功能评估的一部分，无论他们在肺量计检查中是否表现出限制性模式。
