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Abstract

Introduction: Oxidative stress plays a key role in the pathophysiology of sepsis. The glutathione redox cycle is an important innate antioxidant system. The aim of this study was to investigate whether the changes in the components of the glutathione redox cycle, such as, reduced nicotinamide adenine dinucleotide phosphate (NADPH), reduced glutathione (GSH), and glutathione peroxidase (GPx) activity during the early period of therapy were associated with the 28-day mortality of patients with septic shock. Methods: This study was a prospective observational study conducted in a 12-bed intensive care unit (ICU) of a tertiary referral hospital. Consecutive patients admitted to the ICU with septic shock were enrolled from September, 2012 to February, 2013. According to the 28-day mortality, the enrolled patients were divided into the two groups: the survivors and the non-survivors. We obtained serum samples from the patients at admission (0 hr), 24 hrs (24 hrs), and 72 hrs after admission (72 hrs). We measured the serum levels of NADPH, GSH, and malondialdehyde (MDA) and GPx activity. Then we compared the data between the survivors and the non-survivors. Results: Fifty patients were enrolled in this study. Thirty-four patients were grouped into the survivors and sixteen into the non-survivors. Age and the severity scores including APACHE II score and SOFA score of the survivors were lower than those of the non-survivors (p = 0.013, p < 0.001, and p < 0.001, respectively). There were no significant differences in gender, co morbidity, pathogen, infection site, and the interval from visit to antibiotics treatment between the two groups. During the first 72 hrs of therapy, the serum levels of NADPH and GSH of the survivors were higher than those of the non-survivors (p = 0.006 and p = 0.001, respectively), and serum MDA level of the survivors were lower than that of the non-survivors (p = 0.008). There were no significant differences in serum GPx activity between the two groups. Conclusions: Low serum NADPH and GSH levels were associated with the increase of serum MDA level and the 28-day mortality of patients with septic shock.