Blood transfusion in critical care

Blood transfusion is frequent in critical care. Transfusion raises the mass of transfused blood components and is lifesaving in acute hemorrhage. In massive transfusion (>10 units of red blood cells), early attempts to restore coagulation function appear helpful. Transfusion in non-bleeding patients is largely prophylactic, is seldom evidence-based, and may be deleterious. In hemodynamically stable critical care patients, level I evidence suggests that a hemoglobin of >7 g/dL and platelet counts of >10,000/μL are well tolerated.