Role of central venous oxygen saturation in experimental sepsis

Abstract

The mixed venous oxygen saturation is a key metabolic parameter to evaluate oxygen metabolism and tissue perfusion under pathologic conditions. Since mixed saturation measurements require pulmonary artery catheterization, central venous saturation (superior cava vein) has been proposed as a less invasive parameter. Thus, central venous saturation was proposed as part of the Early Goal Directed Therapy strategy, during septic shock resuscitation for more than 10 years. However, this strategy has been questioned by recent clinical studies. The purpose of the investigation was to study the value of venous oxygen saturation in different vascular compartments in an endotoxic shock animal model.

A secondary data base analysis was made from a previous experimental project entitled “Sepsis and Multiple Organ Dysfunction. Early goal directed resuscitation and coadjuvant therapies”.
There was a significant correlation between central and mixed venous saturation. However, these parameters were not equivalent. The contribution of the different venous compartments to the mixed venous value, varied following systemic hemodynamic changes generated by resuscitation. Both, decreases and increases of mixed venous saturation were accompanied by significant arterial lactate increments. Thus, high mixed venous values do not rule out tissue disoxia. The simultaneous measurement of arterial lactate and mixed venous saturation could be useful to identify tissue oxygenation disorders during endotoxic shock.