Stewart R I
Department of Medical Physiology and Biochemistry, University of Stellenbosch, Cape Town, South Africa.
Chest. 1988 Aug;94(2):332-6. doi: 10.1378/chest.94.2.332.
The aim of this study was to test the hypothesis that carbon monoxide diffusing capacity (DCO) is elevated in asthmatic patients with minimal airflow limitation and/or hyperinflation; the latter factors should reduce the possibility of technical errors in the measurement of DCO. In ten asthmatic and ten healthy subjects, DCO and its components, membrane diffusing capacity (Dm) and pulmonary capillary blood volume (Qc) were measured by the single-breath method. Values were normalized for alveolar volume (VA). The mean DCO/VA was higher in the asthma groups as was the Qc/VA. The Dm/Qc was also higher in the asthma group. In the asthmatic but not the healthy subjects, both DCO/VA and Qc/VA were negatively correlated with the forced expiratory flow at 50 percent of vital capacity and peak inspiratory flow rate. Thus, DCO/VA may be increased in asthmatic patients with only mild airflow limitation; this may be due to an elevated capillary blood volume.
在气流受限和/或肺过度充气程度最小的哮喘患者中，一氧化碳弥散量（DCO）升高；后述因素应可降低DCO测量中技术误差的可能性。对10名哮喘患者和10名健康受试者采用单次呼吸法测量DCO及其组成部分，即膜弥散量（Dm）和肺毛细血管血容量（Qc）。各项数值以肺泡容积（VA）进行标准化。哮喘组的平均DCO/VA和Qc/VA均较高。哮喘组的Dm/Qc也较高。在哮喘患者而非健康受试者中，DCO/VA和Qc/VA均与肺活量50%时的用力呼气流量及吸气峰值流速呈负相关。因此，在仅存在轻度气流受限的哮喘患者中，DCO/VA可能升高；这可能是由于毛细血管血容量增加所致。
