Farebrother M J, McHardy G J, Munro J F
Br Med J. 1974 Aug 10;3(5927):391-3. doi: 10.1136/bmj.3.5927.391.
Relations between expiratory reserve volume (ERV), closing volume (CV) as a percentage of vital capacity (CV/VC%), and pulmonary gas exchange have been investigated in the sitting and supine postures in eight severely obese subjects before and after substantial weight loss. CV/VC% exceeded predicted values but did not change with posture or weight loss; the increase could have been owing to the smoking habits of the subjects. Arterial oxygen pressure (PaO(2)) was significantly less in the supine than in the sitting posture and improved after weight loss in six subjects. The reduction in PaO(2) was correlated with the extent to which dependent airways were closed within the range of tidal breathing, shown by increasing negativity of ERV-CV as a percentage of VC. A good correlation was also found between PaO(2) and ERV, an easier measurement for routine use. Improvement of pulmonary gas exchange occurred only in those patients who lost weight to within 30% in excess of ideal.
在8名重度肥胖受试者体重显著减轻前后,对其坐位和仰卧位时的呼气储备量(ERV)、闭合容量(CV)占肺活量的百分比(CV/VC%)以及肺气体交换之间的关系进行了研究。CV/VC%超过预测值,但不随体位或体重减轻而改变;这种增加可能归因于受试者的吸烟习惯。仰卧位时的动脉血氧分压(PaO₂)显著低于坐位,6名受试者体重减轻后有所改善。PaO₂的降低与潮气呼吸范围内依赖气道的闭合程度相关,表现为ERV - CV占VC的百分比负值增加。在PaO₂与ERV之间也发现了良好的相关性,ERV是更便于常规使用的测量指标。只有那些体重减轻至超过理想体重30%以内的患者,肺气体交换才有所改善。