The authors present an revolutionary study aiming to evaluate the effect of alterations in potassium concentrations in transfused packed red blood cells (PRBC) on neonate and infant potassium levels after congenital cardiac surgery. By establishing a strict protocol which restricts the rate of transfusion, the age of the transfused PRBC, and not transfusing a PRBC with a potassium level above 15 mmol/L, they accomplished to suggest a safe and easy way for preventing transfusion associated hyperkalemia.