Decreased plasma H₂O₂ levels are associated with the pathogenesis leading to COVID-19 worsening and mortality

Oxidative Stress (OS) is involved in the pathogenesis of COVID-19 and in the mechanisms by which SARS-CoV-2 causes injuries to tissues, leading to cytopathic hypoxia and ultimately multiple organ failure. The measurement of blood glutathione (GSH), H2O2, and catalase activity may help clarify the pathophysiology pathways of this disease. We developed and standardized a sensitive and specific chemiluminescence technique for H2O2 and GSH measurement in plasma and red blood cells of COVID-19 patients admitted to the intensive care unit (ICU). Contrary to what was expected, the plasma concentration of H2O2 was substantially reduced (10-fold) in COVID-19 patients compared to the healthy control group. From the cohort of patients discharged from the hospital and those who were deceased, the former showed a 3.6-fold and the later 16-fold H2O2 reduction compared to the healthy control. There was a 4.4 reduction of H2O2 concentration in the deceased group compared to the discharged group. Interestingly, there was no variation in GSH levels between groups, and reduced catalase activity was found in discharged and deceased patients compared to control. These data represent strong evidence that H2O2 is converted into highly reactive oxygen species (ROS), leading to the worst prognosis and death outcome in COVID-19 patients admitted to ICU. Considering the difference in the levels of H2O2 between the control group and the deceased patients, it is proposed the quantification of plasma H2O2 as a marker of disease progression and the induction of the synthesis of antioxidant enzymes as a strategy to reduce the production of oxidative stress during severe COVID-19.HighlightsH2O2 plasma levels is dramatically reduced in patients who deceased compared to those discharged and to the control group.Plasmatic quantification of H2O2 can be possibly used as a predictor of disease progression.Catalase activity is reduced in COVID-19.GSH levels remain unchanged in COVID-19 compared to the control group. H2O2 plasma levels is dramatically reduced in patients who deceased compared to those discharged and to the control group. Plasmatic quantification of H2O2 can be possibly used as a predictor of disease progression. Catalase activity is reduced in COVID-19. GSH levels remain unchanged in COVID-19 compared to the control group.</p

Acute kidney injury and intra-abdominal hypertension in burn patients in intensive care

<p></p><p>ABSTRACT Objective: To evaluate the frequency of intra-abdominal hypertension in major burn patients and its association with the occurrence of acute kidney injury. Methods: This was a prospective cohort study of a population of burn patients hospitalized in a specialized intensive care unit. A convenience sample was taken of adult patients hospitalized in the period from 1 August 2015 to 31 October 2016. Clinical and burn data were collected, and serial intra-abdominal pressure measurements taken. The significance level used was 5%. Results: A total of 46 patients were analyzed. Of these, 38 patients developed intra-abdominal hypertension (82.6%). The median increase in intra-abdominal pressure was 15.0mmHg (interquartile range: 12.0 to 19.0). Thirty-two patients (69.9%) developed acute kidney injury. The median time to development of acute kidney injury was 3 days (interquartile range: 1 - 7). The individual analysis of risk factors for acute kidney injury indicated an association with intra-abdominal hypertension (p = 0.041), use of glycopeptides (p = 0.001), use of vasopressors (p = 0.001) and use of mechanical ventilation (p = 0.006). Acute kidney injury was demonstrated to have an association with increased 30-day mortality (log-rank, p = 0.009). Conclusion: Intra-abdominal hypertension occurred in most patients, predominantly in grades I and II. The identified risk factors for the occurrence of acute kidney injury were intra-abdominal hypertension and use of glycopeptides, vasopressors and mechanical ventilation. Acute kidney injury was associated with increased 30-day mortality.</p><p></p