Affiliation:
1. Wadsworth Hospital, Veterans Administration Center, and the Departments of Physiology, Medicine, and Pediatrics, University of California Medical Center, Los Angeles, California
Abstract
Ten experiments were conducted on anesthetized dogs ventilated with a Starling pump and breathing oxygen. While tidal volume, respiratory rate, and arterial pH and pCO
2
were kept constant, lung volume was varied by using either a negative, zero, or positive end-expiratory pressure, leading to average changes in lung volume of -32, 0, and +75 per cent. Pulmonary vascular resistance (PVR) increased with either decreased or increased lung volume, indicating that the relationship between resistance and lung volume is a U-shaped curve. Since the transmural distending pressures of large pulmonary vessels either increased or remained unchanged during these procedures, changes in PVR cannot be ascribed to changes in systemic circulatory dynamics, such as cardiac output.
It was noted that cardiac output increased with negative end-expiratory pressure (effectively, negative-pressure breathing) and decreased with positive end-expiratory pressures (effective, positive-pressure breathing), as previously reported. A hypothesis is presented for explaining the U-shaped curve relating resistance and lung volume.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Cardiology and Cardiovascular Medicine,Physiology
Reference19 articles.
1. Im weleher Respirationspkase ist die Lunge am besten durchblutet? Arch, exper. Path. u;CLOETTA;Pharmakol.,1912
2. Effect on pulmonary vascular resistance of inflation of rabbit Iungs;BURTON A. C;J. Appl. Physiol.
3. Effects of Iung inflation and epinephrine on pulmonary vascular resistance;EDWARDS W. S.;Am. J. Physiol.,1951
4. Pulmonary Blood Flow and Venous Return During Spontaneous Respiration
Cited by
92 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献