[Correlation between oxidative stress factors and prognosis of patients with sepsis]

To investigate the relationship between plasma oxidative stress factors levels and organ damage parameters as well as prognosis in patients with sepsis.

A case-control study was conducted. Twenty-five patients admitted to surgical intensive care unit (ICU) of the First Affiliated Hospital of Sun Yat-sen University from March to December in 2016 and diagnosed as sepsis were enrolled as study subjects. Another 15 patients without sepsis admitted to surgical ICU in the same period were enrolled as controls. General demographic data, main diagnoses, acute physiology and chronic health evaluation II (APACHE II) score within 24 hours, clinical laboratory indicators [alanine aminotransferase (ALT), aspartate transaminase (AST), serum creatinine (SCr), blood urea nitrogen (BUN), C-reactive protein (CRP), procalcitonin (PCT), white blood count (WBC)] and oxidative stress indicators [superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO)] as well as length of ICU stay, total hospital stay and 28-day mortality were recorded. Spearman or Pearson correlation method was used to analyze the correlation between oxidative stress indicators and organ damage indicators as well as prognosis in patients with sepsis. Receiver operator characteristic (ROC) curve was plotted to evaluate the predictive value of oxidative stress indicators for 28-day mortality in patients with sepsis.

The length of ICU stay in sepsis group was significantly longer than that in non-sepsis group [days: 7.0 (5.5, 11.0) vs. 4.0 (1.0, 11.0), P < 0.05], and AST, BUN, CRP, PCT, plasma MDA and NO levels were significantly higher than those in non-sepsis group [AST (U/L): 50.76±19.53 vs. 28.53±14.02, BUN (mmol/L): 9.99±5.26 vs. 6.97±4.32, CRP (mg/L): 109.28±42.79 vs. 60.33±46.68, PCT (μg/L): 5.4 (0.3, 24.0) vs. 0.6 (0.1, 1.5), MDA (ng/L): 488.31±76.68 vs. 399.30±50.23, NO (ng/L): 5.08±0.89 vs. 4.42±0.88, all P < 0.05]. There was no significant difference in gender, age, APACHE II score, total hospital stay, 28-day mortality, ALT, SCr, WBC or plasma SOD activity between the two groups. The correlation analysis between oxidative stress parameters and organ damage parameters as well as prognosis in patients with sepsis showed that MDA and NO were positively correlated with SCr (r value was 0.426 and 0.431, respectively, both P < 0.05), and there was a positive correlation between MDA and NO (r = 0.990, P < 0.01); plasma SOD activity was negatively correlated with 28-day mortality (r = -0.468, P < 0.05), while MDA and NO levels were positively correlated with 28-day mortality (r value was 0.598 and 0.611, respectively, both P < 0.01). ROC curve analysis showed that plasma SOD, MDA and NO levels had a good independent predictive effect on 28-day mortality, the area under ROC curve (AUC) was 0.816±0.087, 0.904±0.078 and 0.912±0.071, and the best cut-off value was 40.76% (sensitivity 68.4%, specificity 100%), 487.93 ng/L (sensitivity 83.3%, specificity 89.5%) and 5.31 ng/L (sensitivity 83.3%, specificity 89.5%), respectively.

The plasma levels of oxidative stress factors in patients with sepsis are significantly increased, which is closely related to organ damage and poor prognosis. The plasma SOD, MDA and NO levels can be used as independent bio-marker to predict the 28-day mortality of patients with sepsis.