慢性阻塞性肺疾病和结缔组织病患者膜弥散与肺血管床容 …

目的 研究慢性阻塞性肺疾病（ＣＯＰＤ）和结缔组织病患者静息及运动后即刻的肺弥散能力（ＤＬ）、肺泡毛细血管膜弥散能力（Ｄｍ）肺泡毛细血管床容量（Ｖｃ）的变化，探讨其对结缔组织病肺改变早期诊断的意义。方法 ＣＯＰＤ组（２０例）及正常对照组２０名，结缔组织病组（２０例）及正常对照组２０名测定静息时不同肺泡气氧分压下的ＤＬ及运动后不同肺泡气氧分压下的ＤＬ，分别按Ｒｏｕｇｈｔｏｎ和Ｆｏｒｓｔｅｒ方法计算静息

Change of pulmonary diffusing capacity, membrane diffusing capacity and pulmonary capillary blood volume in patients with COPD and connective tissue disease at rest and post exercise

Objective Studying the changes of pulmonary diffusing capacity (D L), alveolar capillary membrane diffusing capacity (Dm) and pulmonary capillary blood volume (Vc) in patients with COPD and connective tissue disease (CTD) at rest and post exercise; evaluating the diagnostic values of D L, Dm and Vc in early stage of pulmonary involvement of CTD. Method Spirometry was performed in the sit position. Several measurements of diffusing capacity of the lung for carbon monoxide (D LCO) were measured by single breath method at increasing alveolar oxygen tension. The estimations of Dm and Vc were done by the method of Roughton and Forster. Result (1) In COPD group, the values of D L were lower than that of the control group at rest. The decreases were due to the reduction of Dm, but Vc were normal. In CTD group, all the value of D L, Dm and Vc were lower than that of its control group at rest. (2) COPD patients had the higher D L, Dm and Vc after the end of exercise than that of at rest. But the changes of D L Dm and Vc in COPD patients were lower compared with the control group. In contrast to the control group, D L, Dm and Vc did not increase or even decreased after the end of exercise in CTD group. (3) There was no significant differences of D L, Dm and Vc between the 7 CTD patients with normal pulmonary volume and D LCO and the control subjects at rest. But after the end of exercise, D L, Dm and Vc of CTD patients kept unchanging or even decreasing. The difference between CTD patients and its control group was found significant. Conclusion The measurements of post exercise Dm and Vc are sensitive tests for pulmonary involvement in of CTD patients. The results are abmormal much earlier in subject with minimal dyspnea and roentgenologic change. They are useful tests for early stage CTD.