Keens T G, Mansell A, Krastins I R, Levison H, Bryan A C, Hyland R H, Zamel N
Chest. 1979 Jul;76(1):41-4. doi: 10.1378/chest.76.1.41.
To explain why the single-breath carbon monoxide diffusing capacity (Dsb) was, on the average, elevated in 163 asthmatic subjects and 175 patients with cystic fibrosis, we simulated this elevation in ten normal subjects by having them perform the test for Dsb through an inspiratory obstruction. This resulted in an 18 percent increase in Dsb corrected for pulmonary volume. Inhalation of a bronchodilator drug was associated with relief of obstruction and a fall in the corrected Dsb in 31 asthmatic subjects but did not change either the obstruction or the corrected Dsb in 17 patients with cystic fibrosis. We suggest that elevated Dsb in asthma and cystic fibrosis is partly due to maximal inspiration against obstructed airways. This requires abnormally negative intrathoracic pressures, increasing the pulmonary capillary blood volume, and, thereby, increasing the Dsb.
为了解释为什么163名哮喘患者和175名囊性纤维化患者的单次呼吸一氧化碳弥散量（Dsb）平均升高，我们让10名正常受试者通过吸气阻塞进行Dsb测试，模拟出这种升高情况。这使得校正肺容积后的Dsb增加了18%。吸入支气管扩张剂与31名哮喘患者的阻塞缓解及校正后的Dsb下降有关，但对17名囊性纤维化患者的阻塞情况或校正后的Dsb均无影响。我们认为，哮喘和囊性纤维化患者Dsb升高部分是由于气道阻塞时的最大吸气所致。这需要异常的胸腔内负压，增加肺毛细血管血容量，从而增加Dsb。
