Prognostic value of the reactive oxygen species in severe sepsis and septic shock patients: a pilot study

BACKGROUND: Reactive oxygen species (ROS) have been shown to play a role in the pathophysiology of sepsis. The aim of this study was to investigate ROS production over time in critically ill with sepsis patients and its correlation with outcome. METHODS: This was a pilot single-centre prospective, observational study of patients consecutively admitted to our 18-general ICU. Over a period of 6 months all the consecutive patients with recent-onset of severe sepsis or septic shock were enrolled. Clinical and demographic characteristics of all patients were recorded. ROMs (ROS metabolites), reduced sulfhydryl groups (SH) and plasmatic lactate levels were collected at enrollment in the study and then every 5-7 days over 28 days or until sepsis resolution or death during sepsis. ROMs were analysed spectrophotometrically by the d-ROMs test (Diacron-Italia). SH were assayed in plasma by Ellman's reaction by spectrophotometric method. Septic shock-related mortality was defined as death that occurred during the follow up period, when the signs of shock remained, and death could not be attributed to causes other than septic shock by the attending physician. RESULTS: Twenty-five patients were studied. The SOFA score and the plasmatic lactate levels significantly correlated with the ROMs plasmatic levels. The mortality rate was higher in patients whose ROMs plasmatic levels decreased during septic shock evolution. CONCLUSIONS: Serial measurements of the ROMs plasmatic levels together with the SOFA score and lactate levels could help to identify septic shock patients with a very high probability of death.