[Hemodynamics, lymphatic circulation and ultrastructure of the lungs during hemodilution with blood substitutes]

The effect of substitution hemodilution on transcapillary fluid exchange in the lung was studied in experiments on 30 dogs. After administration of Ringer's solution and of oncotic solutions (3.4% and 10% Rheodextran), the lymph flow through the right lymphatic trunk was measured and the protein content in the lymph was determined. The obtained results were compared with electron micrographs of the lung. Ringer's solution was found to escape rapidly from the vascular bed. A 3.9-fold increase in lymph flow was recorded and edematous changes were observed in the interstitial space. Administration of 10% Rheodextran induced an 8.3-fold increase of lymph flow and enhanced also the protein transport in the lymph. The permeability of pulmonary endothelial vascular walls was deranged. Isooncotic 3.4% Rheodextran provided adequate transcapillary exchange of fluids in the lungs and proved to be the suitable solution for substitution of blood losses. In the ultrastructure of the lungs no pathological changes were observed. (Fig. 8, Ref. 33).