Plasmapheresis-induced hemodilution and its effects on serum constituents

Samples were obtained from 23 plasmapheresis donors before, during, and after double plasmapheresis. Seventeen chemical analyses were performed on these specimens and the results were subjected to statistical analysis. Representative samples can be obtained from plasmapheresis donors before the procedure has begun, immediately after the first unit of whole blood has been removed, or 15 minutes after the completion of the entire procedure. The sample obtained after the first unit of whole blood has been removed will show dilutional lowering of the uric acid concentration and the 15-minute equilibration sample will show dilutional lowering of the inorganic phosphorus concentration. Short-term donors and long-term donors manifest a somewhat different hemodilutional response to plasmapheresis.