354 Central Venous Oxygen Saturation Related With Mitochondrial Dysfunction in Sepsis Patients

Abstract

An increased mitochondrial oxidative stress has an association with blood lactate, ScvO2, delta CO2, and survival rate in patients with sepsis. This was a prospective, observational study. Patients who visited the emergency department with suspected sepsis were included. Blood lactate, central venous oxygen saturation (ScvO2), and venous-to-arterial carbon dioxide tension difference (delta CO2) were documented. In addition, mitochondrial oxidative stress assessed by MitoSOXTM and mitochondrial mass were determined from peripheral blood mononuclear cells (PBMCs) for determination of mitochondrial function in all patients. Forty-six patients were enrolled, of which 38 patients were diagnosed with sepsis (sepsis-related organ failure assessment (SOFA) score ≥ 2). Mitochondrial oxidative stress was increased in sepsis patients with high SOFA score (SOFA > 5), compared with low SOFA score (SOFA 2-5) (20.44 versus 13.14; P=0.04). When sepsis patients were categorized into 3 groups according to the ScvO2 levels; Low-ScvO2 (<70%, n=5), normal-ScvO2 (70-80%, n=9), and high-ScvO2 (>80%, n=6), our results showed that the level of mitochondrial oxidative stress was higher in the high ScvO2 group, compared with normal and low ScvO2 groups (P=0.01). Moreover, a strong linear relationship was observed between the ratio of mitochondrial oxidative stress/mitochondrial mass and ScvO2 (r=0.75; p=0.01). However, there was no correlation between mitochondrial oxidative stress and lactate or mitochondrial oxidative stress and delta CO2. Data also showed that the survival rate was not different among these groups. To our knowledge, this is the first demonstration that ScvO2 could be used as a marker for mitochondrial dysfunction in sepsis. Moreover, ScvO2 may potentially be useful for developing novel therapeutic strategies to attenuate mitochondrial dysfunction in sepsis patients.