Robertson C H, Engle C M, Bradley M E
J Appl Physiol Respir Environ Exerc Physiol. 1978 May;44(5):679-82. doi: 10.1152/jappl.1978.44.5.679.
Previous studies of lung volumes during immersion have utilized dilution techniques for residual volume. We have compared lung volumes obtained by the use of a dual inert gas dilution technique with those determined by the Boyle's law technique in a plethysmograph designed to allow measurements in air and submersed to the neck in water. Both techniques gave similar results dry, but during immersion the dilution residual volume (RV) was 0.200 liter (16%) lower than the plethysmographic value (P greater than 0.001), which suggests that there is a significant amount of gas trapping during immersion due to breathing at low lung volumes and the central shift of blood. The unchanged RV due to hydrostatic force on the chest wall is balanced by the tendency to increase RV due to vascular congestion, which increases closing volume and stiffens the lung to compression.
以往关于浸入过程中肺容积的研究采用稀释技术来测定残气量。我们在一台设计用于在空气中及颈部浸入水中时进行测量的体积描记器中，将使用双惰性气体稀释技术获得的肺容积与通过波义耳定律技术测定的肺容积进行了比较。两种技术在干燥状态下得出的结果相似，但在浸入过程中，稀释残气量（RV）比体积描记法测得的值低0.200升（16%）（P>0.001），这表明在浸入过程中，由于低肺容积呼吸和血液的中心转移，存在大量气体潴留。胸壁上的静水压力导致的残气量不变，与血管充血导致的残气量增加趋势相平衡，血管充血会增加闭合气量并使肺变硬以抵抗压缩。
