Frazier A R, Rehder K, Sessler A D, Rodarte J R, Hyatt R E
J Appl Physiol. 1976 Mar;40(3):305-11. doi: 10.1152/jappl.1976.40.3.305.
Single-breath oxygen (SBO2) tests for individual lungs were performed in five healthy awake volunteers. In the supine position, all subjects consistently showed a closing volume (CV) for both lungs. In the lateral position, CV was demonstrated in all analyzable SBO2 tests for the dependent and in 20 of 28 for the nondependent lung. CV consistently occurred in the dependent before it occurred in the nondependent lung (asynchronous onset of CV). After CV had been reached in the nondependent lung, a mean of 77 ml of gas was still expired from the dependent lung. No changes in CV for individual lungs were demonstrated with changes in body position. Expiratory flow limitation consistently occurred first in the dependent lung (asynchronous onset of flow limitation). In the lateral position, at high lung volumes, the dependent lung achieved higher flow rates; later in expiration, the nondependent lung contributed progressively more gas to the total expirate (asynchronous emptying). In general, our findings are consistent with both the "asynchronous flow limitation" and the "airway closure" interpretations of CV. However, some of the results are not consistent with either theory.
对五名健康清醒志愿者的单个肺进行了单呼吸氧气（SBO2）测试。在仰卧位时，所有受试者的双肺均持续显示闭合气量（CV）。在侧卧位时，所有可分析的SBO2测试中，下垂肺均显示出CV，而非下垂肺在28次测试中有20次显示出CV。CV在下垂肺中总是先于非下垂肺出现（CV的异步发作）。在非下垂肺达到CV后，下垂肺平均仍有77毫升气体呼出。未发现个体肺的CV随体位变化而改变。呼气流量受限总是先出现在下垂肺中（流量受限的异步发作）。在侧卧位时，在高肺容量时，下垂肺的流速更高；在呼气后期，非下垂肺对总呼出气体的贡献逐渐增加（异步排空）。总体而言，我们的发现与CV的“异步流量受限”和“气道闭合”两种解释均相符。然而，有些结果与这两种理论都不一致。
