The volume-expanding effects of autologous liquid stored plasma following hemorrhage

Background. Plasma use has increased since studies have suggested that early treatment with blood components in trauma with severe hemorrhage may improve outcome. Plasma is also commonly used to correct coagulation disturbances in non-bleeding patients. Little is known about the effects of plasma transfusion on plasma volume. We report a prospective interventional study in which the plasma volume-expanding effect of autologous plasma was investigated after a controlled hemorrhage. Methods. Plasma obtained by plasmapheresis from nine healthy regular blood donors was stored at 2-6 degrees C. Five weeks after donation the subjects were bled of 600 ml and then transfused with 600 ml of autologous plasma. Plasma volume was estimated using 125 I-albumin before and after bleeding, and immediately after plasma transfusion. Plasma volume changes were then estimated by measuring changes in hematocrit during the following 3-h period. Results. Estimated plasma volume after bleeding was 3170 +/- 320 ml and 3690 +/- 380 ml (mean +/- standard deviation) immediately following the transfusion of plasma (p < 0.05). This increase in plasma volume corresponds to 86 +/- 13% of the infused volume. Three hours after transfusion, plasma volume was still 3680 +/- 410 ml. Conclusions. Stored liquid plasma has a plasma volume expanding effect up to 86% of its infused volume with a duration of at least 3 h.