氦稀释法与体积描记法测定正常人和哮喘病人功能残气量的比较

The Comparison of Functional Residual Capacity Measured by Helium Dilution Method and Body Plethysmography in Healthy Subjects and Patients with Asthma

本文用氦稀释法和体积描记法同时测定５３例正常人，２５例哮喘病人肺容量指标。结果表明，正常人功能残气量在两种方法间无差别，而残气量体积描记法明显高于氨稀释法；在哮喘病人，功能残气量在两种方法间差别显著增大。此差别与气道狭窄时体积描记法测定功能残气量失真有关。

he functional residual capacity(FRC)in 53 healthy subjects and 25 patients with asthma(11 and14 cases in remission and attack stage each)was measured by helium dilution method and body plethys-mography.It was found that FRC obtained by plethysmography(2.98L)was slightly higher than thatby helium dilution method(2.88L)in healthy subjects. But there was no significant difference betweenthe two methods. The residual volumn(RV)obtained by plethysmography was markedly larger thanthat by helium dilution method(1.79 and 1.49L respectively,P<0.01).The difference was related tothe size of expiratory residual volumn.The difference of FRC measured with the two methods was markedly increased in patients withasthma. FRC obtained from plethysmography was significantly larger than that from helium dilutionmethod(5.44L and 3.42L respectively,P<0.01)during attack stage of asthma. This difference wasrelated to the distortion of FRC measured with plethysmography when patients’airway was obstructed.