Anemia and Clinical Outcomes

The anesthesiologist and the surgeon, followed by the oncologist, are among the largest consumers of blood products,. Typically, between 60% and 70% of all red blood cell units are transfused in the surgical setting [1] In the authors’ facility, a tertiary care university medical center, the consumption of blood products by service is shown in Table 1. Surgical patients used 42% of the RBC and 40% of all the other blood components used in the hospital over a 1-year period. Of the total RBC used, 36% of red blood cells were used during surgery, and 64% were used during the postoperative time period. Pathophysiology of anemia Patients in the perioperative setting are at a risk of anemia primarily from blood loss during surgery. In anemia, even at hemoglobin levels well below 10 g/dL the o2 carrying capacity is decreased, but tissue oxygenation is preserved. Anemia causes hemodynamic alterations. The combined effect of hypovolemia and anemia often occur as a result of blood loss. Acute anemia thus may cause tissue hypoxia or anoxia through diminished cardiac output, resulting in stagnant hypoxia, and decreased o2-carrying capacity (anemic hypoxia) (Table 2)