Anemia tolerance during normo-, hypo-, and hypervolemia

The Limits of Acute Anemia

For many years, physicians’ approach to the transfusion of allogeneic red blood cells (RBC) was not individualized. It was accepted that a hemoglobin concentration (Hb) of less than 10 g/dL was a general transfusion threshold and the majority of patients were transfused immediately. In recent years, there has been increasing evidence that even significantly lower hemoglobin concentrations can be survived in the short term without sequelae. This somehow contradicts the observation that moderate or mild anemia is associated with relevant long-term morbidity and mortality. To resolve this apparent contradiction, it must be recognized that we have to avoid acute anemia or treat it by alternative methods. The aim of this article is to describe the physiological limits of acute anemia, match these considerations with clinical realities, and then present “patient blood management” (PBM) as the therapeutic concept that can prevent both anemia and unnecessary transfusion of RBC concentrates in a clinical context, especially in Intensive Care Units (ICU). This treatment concept may prove to be the key to high-quality patient care in the ICU setting in the future.

Management of anemia in patients who decline blood transfusion

Declining a treatment modality should not be considered the same as refusal of medical care as illustrated by the management of Jehovah's Witness patients who do not accept transfusions. Over the years, a comprehensive set of strategies have been developed to meet the specific needs of these patients and these strategies are collectively called "Bloodless Medicine and Surgery" (BMS). The focus in BMS is to optimize the patients' hematopoietic capacity to increase hemoglobin (Hgb) level, minimize blood loss, improve hemostasis, and provide supportive strategies to minimize oxygen consumption and maximize oxygen utilization. We present 3 case reports that illustrate some of the challenges faced and measures available to effectively treat these patients. Under BMS programs, patients with extremely low hemoglobin levels, not conducive to survival under ordinary conditions, have survived and recovered without receiving allogeneic transfusions. Additionally, the valuable experience gained from caring for these patients has paved the way to develop the concept of Patient Blood Management as a standard care to benefit all patients, and not only those for whom blood is not an option.