Debate: Transfusing to normal hemoglobin levels improves outcome.

Red cells are uniquely designed to transport oxygen and facilitate oxygen uptake by systemic tissues. Blood transfusions are thus logical therapeutic choices in patients who exhibit signs of oxygen debt. A small number of studies that have addressed patients with metabolic or physiologic signs of oxygen debt or regional ischaemia suggest that liberal blood transfusion strategies improve outcome. Therefore, armed with an understanding of the variety of clinical presentations characterising oxygen debt, as well as an appreciation of the risks involved, blood transfusions should be considered in all critically ill patients. This includes the consideration of liberalized hemoglobin triggers and hemoglobin thresholds in normal ranges.