Indirect measures of oxygenation, such as a decreased SvO 2 or central venous oxygen saturation (ScvO 2 ), also may be considered [82] . For example, in a study of early goal-directed therapy in patients with severe sepsis or septic shock admitted to an emergency department, a decrease in ScvO 2 < 70% initiated a therapeutic intervention, including fluid resuscitation, inotropes, vasopressors, and RBC transfusion to increase hematocrit to > 30% [50] . Use of a decreased ratio of cardiac index to oxygen extraction (CI/EO 2 ratio) may be better, because this parameter also reflects the cardiac response to anemia [83] .