Red blood cell transfusion in paediatric critical care

Many children receive one or more units of red blood cell (RBC) preparations during their paediatric intensive care unit (PICU) admission depending on their underlying disease course. Physicians often justify RBC transfusions in critically ill children when anaemia is present because of the assumption that by increasing the haemoglobin level the delivery of oxygen (DO2) to peripheral tissues is improved so that ultimately the oxygen utilization (VO2) can be improved. However, the question whether or not the presence of anaemia in critically ill children is associated with adverse outcome cannot be answered easily. The TRIPICU study has clearly shown that it is safe to refrain from transfusing stable critically ill children unless their Hb has dropped below 7 g/dL (4.3 mmol/L) as increasing data emphasizes that the common practice of transfusing critically ill children is not free from causing harm as shown by increased morbidity and mortality. This narrative review summarizes the current literature and discusses possible pathophysiological mechanisms.