A nurse is planning care for a client who is to receive packed RBCs. The nurse should plan for the total infusion time to not exceed which of the following?

Packed red blood cells (PRBCs) must be infused within a specific time frame to ensure patient safety and blood product integrity. The standard guideline from organizations such as the American Association of Blood Banks (AABB) and most clinical protocols specifies that each unit of packed RBCs must be infused within a maximum of four hours. This time limit exists because blood kept at room temperature beyond four hours is at significant risk for bacterial proliferation, hemolysis, and degradation, which can cause a transfusion reaction or infection in the recipient. Infusing over six or eight hours dramatically increases microbial growth risk and compromises the viability of the red cells. Two hours is not the maximum — while many units can be transfused in under two hours, some patients (such as those at risk for fluid overload) may require a slower rate, and the outer limit remains four hours. If a transfusion cannot be completed within four hours due to a slow infusion rate, the remaining blood should be returned to the blood bank and discarded. Nurses must monitor the start time carefully and adjust flow rates appropriately to complete each unit within this four-hour window.