Effects of acute plasma for blood exchange in experimental polycythemia

This study was performed to assess the effects of equal volume plasma-for-blood exchanges in the chronically polycythemic dog. Red blood cells were periodically injected until the hematocrit exceeded 60%. Thereafter, the hemodynamic effects of five plasma-for-blood exchanges (8 ml/kg/exchange) were compared to values obtained during control, maximal polycythemia, and a recovery period. Cardiac output decreased 40% (p less than 0.01) during maximal polycythemia and increased significantly after the first two exchanges. In chronically polycythemic dogs, plasma-for-blood exchanges that decreased the hematocrit to 56-62% reverted selected cardiovascular parameters to or toward control values.