Upstream pressure for systemic to pulmonary flow from bronchial circulation in XXXX .

@entity712 @entity8995 @entity63 @entity235 @entity2286 @entity3885 @entity2507
Systemic to pulmonary flow from bronchial circulation, important in perfusing potentially @entity63 regions distal to @entity3885 , depends on driving pressure between an upstream site in intrathoracic systemic arterial network and pulmonary vascular bed. The reported increase of @entity8995 in @entity712 may be due to a reduction of this driving pressure. We measured upstream element for driving pressure for systemic to pulmonary flow from bronchial circulation by raising pulmonary venous pressure ( @entity2286 ) until the systemic to pulmonary flow from bronchial circulation ceased. We assumed that this was the same as upstream pressure when there was flow. Systemic to pulmonary flow from bronchial circulation was measured in left lower lobes (LLL) of 21 anesthetized open-chest @entity235 from volume of blood that overflowed from pump-perfused (90-110 ml/min) pulmonary vascular circuit of LLL and was corrected by any changes of LLL fluid volume (wt). Systemic to pulmonary flow from bronchial circulation upstream pressure was linearly related to systemic arterial pressure (slope = 0.24, R = 0.845). Increasing @entity2286 caused a progressive reduction of systemic to pulmonary flow from bronchial circulation, which stopped when @entity2286 was 44 +/- 6 cm @entity2507 and pulmonary arterial pressure was 46 +/- 7 cm @entity2507 . A further increase in @entity2286 reversed systemic to pulmonary flow from bronchial circulation with blood flowing back into the @entity235 . When net systemic to pulmonary flow from bronchial circulation by the overflow and weight change technique was zero a small bidirectional flow (3.7 +/- 2.9 ml.min-1 X 100 g dry lobe wt-1) was detected by dispersion of tagged red blood cells that had been injected.(ABSTRACT TRUNCATED AT 250 WORDS)
