Demedts M, Clarysse I, Verhamme M, Marcq M, De Roo M
J Appl Physiol Respir Environ Exerc Physiol. 1983 Feb;54(2):361-5. doi: 10.1152/jappl.1983.54.2.361.
Regional distributions of inspired 133Xe and single-breath washout curves were compared in six young healthy subjects for the upright and the head-down positions. The regional distributions of volumes (at 0, 25, 50, and 75% vital capacity, VC) and of 133Xe boluses inhaled at residual volume (RV) were inverted in the head-down position, thus behaving as if they were determined by gravity acting via the weight of the lung rather than by thoracicoabdominal shape adaptations. Nevertheless no mirror image was obtained. The vertical differences in regional distribution of the 133Xe RV bolus and of the volumes at 25% VC were increased in the head-down position, whereas the vertical difference in volumes at RV was decreased, indicating enhanced air trapping and sequential ventilation at low volumes. This was attributed to the effect of the increased pulmonary blood volume in the head-down posture. Accordingly the size of phase IV on the washout curves with the SF6-bolus as well as with the N2-resident gas method was increased in the head-down position.
在6名年轻健康受试者中，比较了直立位和头低位时吸入的133Xe的区域分布及单次呼吸洗脱曲线。头低位时，残气量（RV）处吸入的133Xe团注以及肺活量（VC）的0%、25%、50%和75%时的容积区域分布发生倒置，因此其表现就好像是由重力通过肺的重量起作用决定的，而非胸廓腹部形状适应决定。然而，并未获得镜像。头低位时，133Xe RV团注及25%VC时容积的区域分布垂直差异增加，而RV时容积的垂直差异减小，表明低容积时空气潴留和序贯通气增强。这归因于头低位时肺血容量增加的影响。因此，头低位时，使用SF6团注法以及N2滞留气体法的洗脱曲线上IV期的大小增加。
