The oxidative stress indicators of patients with different severity of sepsis. A. MDA level in patients with different severity of sepsis. B. SOD activity in patients with different severity of sepsis. C. GSH-Px activity in patients with different severity of sepsis. MDA, malonaldehyde; SOD, superoxide dismutase; GSH-Px, glutathione peroxidase. a, compared with sepsis P<0.05; b, compared with severe sepsis P<0.05.