Is There an Optimal Perioperative Hemoglobin?

The blood supply in the United States is extremely safe, although blood transfusions are not without risks. Anemia in the perioperative setting presents a unique challenge to clinicians because perioperative anemia has been associated with poor outcomes, but in the past, clinical trial data were lacking on when red blood cell transfusion improves outcomes. Furthermore, the hemoglobin threshold at which a transfusion should be administered was uncertain. Recently new large clinical trials have become available to help guide clinicians. These data suggest that a more restrictive hemoglobin threshold of 7 g/dL to 8 g/dL may be appropriate for most perioperative and critical care patients, even those with existing cardiovascular disease. This chapter explores the evidence behind this and provides recommendations regarding perioperative and critical care blood transfusions, incorporating the most recent clinical trials. It also presents directions for further research.