Pulmonary capillary pressure and filtration coefficient in the isolated perfused lung

Abstract

An "isogravimetric" method was used to estimate the pulmonary capillary pressure, to determine the arterial and venous resistances in the isolated perfused lobe of a dog''s lung, and to determine its filtration coefficient. The average pulmonary capillary pressure found in 51 experiments was 7.0 + 1.4 mm Hg SD. The average pulmonary arterial and venous resistances were 0.018 and 0.014 mm Hg/ml/min; respectively. The relative distribution of these resistances in relation to total resistance of the lobe was approximately 56% arterial and 44% venous. The filtration coefficient for the pulmonary capillary membrane was 0.070 [plus or minus] 0.010 SD g/mm Hg/min./100 g of tissue.