Should We Universally Adopt a Restrictive Approach to Blood Transfusion? It's All About the Number

Accumulating evidence from clinical trials suggests that administering blood transfusions once the hemoglobin falls below either 7 or 8 g/dL--a restrictive transfusion strategy--is safe in most clinical settings. Safely limiting exposure to blood is important because transfusions are common, with more than 16 million red blood cell units transfused annually to 3.4 million people in the US and 85 million units worldwide. It's therefore important to administer blood to patients where benefits outweigh risks. Here, Carson and Hebert discuss the result of the Cochrane review of clinical trials they have performed to evaluate transfusion trigger in a variety of populations.