As stated in our article, according to these findings, a central Svo2 of 70% corresponds to a femoral Svo2 range of 58.8% to 81.2%. A value of 58.8% would prompt the physician to optimize oxygen delivery by means of volume resuscitation, blood transfusion, or the initiation of inotropic agents. Yet, a value of 81.2% alone would not generate the same intervention. Thus, we believe that the femoral Svo2 cannot reliably be used to make clinical decisions or guide resuscitation. Svo2 values differ among organ systems because each organ extracts variable amounts of oxygen, particularly in states of physiologic stress. Absolute values of venous oxygenation, therefore, depend greatly on the site of measurement. It has been well established that the mixed Svo2 value obtained from the distal port of a pulmonary artery catheter reflects the venous return from both the upper and lower portions of the body and, therefore, is a marker of global tissue hypoxia.2 However, it is important to note that the standard femoral venous catheters are 20 cm in length. In the average-sized adult, the tip, and hence the venous sampling, is within the iliac vein and not in the inferior vena cava. Thus, Svo2 from the intraabdominal organs, including the liver, kidney, and splanchnic regions, is not necessarily sampled. A low femoral Svo2, therefore, may not necessarily reflect a redistribution of blood flow to indicate that global tissue hypoperfusion is present.