The diminished efficiency and altered dynamics of respiration in experimental pulmonary congestion

Quantitative measurements of the relative efficiency of respiration in the normal lung, as contrasted with the congested lung, have not been made in the intact experimental animal. In 1934 Christie and Meakins,¹ utilizing simultaneous determinations of dynamic intrapleural pressure and of tidal exchange in patients with congestive heart failure, demonstrated a marked decrease in pulmonary distensibility. With appropriate treatment, distensibility was found to increase as the patient improved. In the present study, an approach similar to that of these authors has been used, and studies of the efficiency of respiration have been made on normal dogs at rest and during hyperpnea (produced by the inhalation of carbon dioxide) and contrasted with the relative efficiency of respiration after pulmonary congestion induced by rapid venous infusion. With this approach, a quantitative comparison of the work necessary to achieve a given amount of tidal exchange has been possible in an animal with normal lungs and in the same animal after severe pulmonary congestion. From measurements of tidal exchange, ventilation, and intrapleural pressure fluctuations, a representation of the dynamic changes in these factors during progressive pulmonary congestion has been obtained.     

肝功能和药理学在门静脉高压的发病机制和治疗上的重要性

有关门静脉高压最主要、最危险的并发症——食管静脉曲张出血的治疗,由于下列三方面重要而又互有联系的发展,已发生了显著的变化。 1.门静脉高压是伴有自主神经系统活动显著改变的全身性疾病,心输出量增加、外周阻力降低的高动力学状态是其突出的血流动力学变化。 2.业已发现各种体液因素在门静脉高压的发病机制中起着重要的作用,这就提示在门静脉高压中存在某种可逆的因素,从而开辟了