The Potential Predictive Role of Oxidative Stress and Antioxidant Parameters Regarding Mortality and the Type of Causative Agent in Sepsis.

Oxidative stress represents an imbalance between oxidants and antioxidants, with a predominance of oxidants leading to cellular and tissue damage. Given the limited number of studies showing the predictive value of oxidative stress factors regarding sepsis type, the objectives of this study emerged as follows: to determine whether pro-oxidant and antioxidant values could predictively differentiate between Gram-positive (GP) and Gram-negative (GN) sepsis. Additionally, the study sought to assess whether bacterial type impacts treatment outcomes in sepsis patients. This prospective, observational cohort longitudinal study included 87 patients diagnosed with sepsis according to the Third International Consensus on Sepsis and Septic Shock (Sepsis-3) criteria. Following the sepsis diagnosis, blood, urine, bronchoalveolar lavage (BAL), and swabs/punctures were sampled and microbiologically analyzed. Sampling was repeated 24 hours after the first collection. Based on the microbiological results, four groups of subjects were formed: the GP group included septic patients in whom one or more GP bacteria were isolated by microbiological analysis; the GN group included septic patients in whom one or more GN bacteria were isolated; the GP/GN group included septic patients with both GP and GN bacteria isolated; and the negative culture (NC) group included septic patients in whom no pathogenic microorganisms were detected by microbiological analysis. Additionally, after sepsis diagnosis, oxidative stress markers, i.e., thiobarbituric acid reactive substances (TBARS), nitrite ion radical (NO₂⁻), hydrogen peroxide (H₂O₂), superoxide ion radical (O₂⁻), and antioxidants: superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) were determined from blood samples. Blood sampling was repeated 24 hours after the first collection. On comparing pro-oxidant values relative to the type of infection in septic patients, measured on the first and second days, no statistically significant differences were observed for the analyzed parameters, except for delta (Δ) O₂⁻. A statistically significant increase was noted in the GN group of septic patients (p = 0.02). On comparing antioxidant values relative to infection type in septic patients, measured on the first and second days, no statistically significant differences were found for the analyzed parameters. Based on the measured values of pro-oxidants and antioxidants in this study, it is evident that they do not have predictive significance for the final treatment outcome and the type of sepsis-causing pathogen. These results underscore the need for further research on the predictive role of oxidative stress in sepsis.