Blood components in the treatment of acute blood loss: use of freeze-preserved red cells, platelets, and plasma proteins.

To avoid untoward reactions from blood transfusions and to make best use of the limited supply of blood, anesthesiologists and surgeons have many newly developed means at their disposal. Blood components should be separated from whole blood at the time of collection and prepared for either liquid or freeze-preservation. Citrate-phosphate-dextrose (CPD) blood should be separated into its components at room temperature within 4 hours of collection for greatest service from each collected unit. Red cell concentrates with hematocrits of 70 volumes percent can be prepared from the whole blood at the time of collection and frozen either shortly thereafter or after storage at 4 degrees C. for up to 3 weeks. Red-cell levels of 2, 3-diphosphoglycerate (2, 3-DPG) and adenosine triphosphate (ATP) can be increased by a rejuvenation process prior to freeze-preservation with either 40 percent W/V glycerol and storage at minus 80 degrees C. or with 20 percent W/V glycerol and storage at minus 150 degrees C. While hemorrhagic shock can best be managed with fresh whole blood, such blood is often not available; liquid- and freeze-preserved products serve as best substitutes. When previously-frozen washed red cells are used, crystalloid, colloid, coagulation factors, and platelets may also be required. Platelet concentrates stored at 4 degrees C. provide platelets that are hemostatically effective immediately upon infusion but have poor circulation. Platelet concentrates stored at 22 degrees C. provide platelets that have good circulation but upon transfusion have impaired hemostatic effectiveness. The coagulation factors and oncotic properties of plasma protein necessary for proper treatment of patients in hemorrhagic shock can be met by an adequate supply of fresh-frozen plasma and albumin. When liquid-stored red-cell concentrates or whole blood is given, filters must be used to remove the accumulated amorphous material, although the actual effects of the infused microaggregates are not yet known.