How much does one unit of packed RBCs typically raise the hematocrit?

One unit of packed red blood cells (RBCs) typically raises the hematocrit by about 3%. This is based on the approximate calculation that each unit of packed cells is expected to increase the hemoglobin level by 1 g/dL or hematocrit by about 3%. This estimate can be useful in clinical settings when managing patients with anemia or those who require transfusions.

Understanding this value is essential for practitioners, especially in perioperative care or during maternal-fetal interventions where maternal anemia may affect fetal well-being. Knowing the expected increase in hematocrit helps to guide transfusion decisions and manage patients effectively.