What is the typical composition of a packed red cell unit?

The typical composition of a packed red cell unit includes 200 mL of red blood cells (RBCs), approximately 100 mL of additive solution, and around 30 mL of plasma. This structure is designed to optimize the storage and preservation of red blood cells while minimizing the volume of plasma, which is primarily composed of water, electrolytes, and proteins.

The additive solution helps to maintain the viability and functionality of the red blood cells during storage. This solution typically contains a nutrient medium that is beneficial for the RBCs, ensuring they remain in good condition until transfusion. The small volume of plasma present may include some residual components from the blood collection process, but it’s largely reduced in packed cell units to enhance the concentration of red cells and reduce the risk of transfusion-related complications.

The proportions in the other options do not accurately reflect standard packed red blood cell units. For instance, some suggest higher volumes of plasma or an incorrect balance with the additives, which does not align with the established practices in blood component preparation.