packed red blood cell

Packed red blood cells are a component of blood used in transfusions. They are what remains after plasma and platelets are removed from whole blood, resulting in a reduced volume.1

The primary function of red blood cells is to transport oxygen from the lungs to the body's tissues and to carry carbon dioxide, a waste product, back to the lungs for excretion. Mature human red blood cells are small, round, and biconcave, lacking a nucleus and containing hemoglobin, a protein that binds oxygen.23

Packed red blood cells are most commonly used to increase low hemoglobin or hematocrit levels in patients with chronic anemia or mild hemorrhage, thereby improving the blood's oxygen-carrying capacity. Blood transfusions, including those using packed red blood cells, became medically useful after the identification of blood types and the development of cross-matching procedures to ensure compatibility between donor and recipient.14