Packed red blood cells
Formal Definition
A blood product consisting of red blood cells with most plasma removed, used to restore oxygen-carrying capacity in anemic or actively bleeding patients; each unit contains approximately 200–250 mL and raises hemoglobin by approximately 1 g/dL (or hematocrit by 3%) in a 70 kg adult without active bleeding.
How It's Used on the Ward
"pRBCs" or "units of blood" or "a unit of packed cells" — standard shorthand for ordering or discussing red cell transfusion.
Example
""GI bleed with hemoglobin of 5.8 and BP trending down: transfusing 2 units pRBCs now, crossmatch for 4 more, GI is on their way for emergent EGD. Each unit should bump Hgb about 1 gram.""
Clinical Context
One unit of pRBC typically raises Hgb ~1 g/dL in a euvolemic adult (less with active bleeding, dilution, or hemolysis). Standard transfuse-1-unit-recheck approach minimizes overexposure. Complications: febrile non-hemolytic reaction (most common — cytokines), allergic reaction (urticaria), acute hemolytic reaction (ABO incompatibility — rare but fatal), TRALI (transfusion-related acute lung injury), TACO (transfusion-associated circulatory overload), transfusion-transmitted infection. Irradiated/CMV-negative products for immunocompromised patients. Pre-transfusion check: confirm ABO compatibility, patient identification (2 identifiers at bedside).