Does blood transfusion cause hyperkalemia or hypokalemia?

Transfusion of stored blood does not cause hypokalemia; instead, it may lead to hyperkalemia.

In a healthy individual, blood potassium levels are maintained within a certain range. A large amount of potassium is normally contained within red blood cells and is released into the bloodstream when red blood cells are naturally destroyed at the end of their lifespan. However, in stored blood, more red blood cells undergo destruction, leading to abnormal release of potassium into the plasma. This excess potassium can enter the patient's body during transfusion, potentially causing hyperkalemia rather than hypokalemia. If a patient already has abnormal potassium levels—either high or low—before transfusion, the transfusion may further affect their serum potassium concentration. For example, if a patient already has hyperkalemia, transfusion could increase blood potassium levels, worsening hyperkalemic symptoms. Conversely, if a patient already has hypokalemia, transfusion might reduce potassium levels further, exacerbating hypokalemic symptoms. Different types of blood products may also have varying effects on potassium levels. For instance, red blood cell transfusions may elevate serum potassium, whereas platelet transfusions may decrease it.

Furthermore, prior to transfusion, physicians typically assess the patient’s potassium levels and select an appropriate type and volume of blood product based on the individual’s clinical condition to avoid adverse effects on potassium balance. After transfusion, close monitoring of potassium levels is essential, and timely interventions should be implemented as needed for correction and treatment.