[Proceedings: The effect of volume manipulation (bloodletting or dextran administration) on pressure in the pulmonary circulation and on the hematocrit].

In a clinical survey the respective effects have been compared of venesection and of hypervolemic hemodilution on hematocrit and pressure in the pulmonary circulation. Whereas after venesection the pressure in the pulmonary circulation and the hematocrit decrease slightly, infusion of 1000 ml Macrodex is followed by marked hemodilution and a distinct increase in pressure in the pulmonary circulation.