Folic acid and vitamin B12 as biomarkers of morbidity and mortality in patients with septic shock.

Introduction and objective: a study was made of the folic acid (Fol) and vitamin B12 (B12) serum concentrations in critical patients with septic shock upon admission and after three days of stay in the Intensive Care Unit (ICU), with an analysis of their association to inflammatory parameters and patient morbidity-mortality. Methods: a prospective analytical study was made of 30 critically ill patients with septic shock. Demographic data, comorbidities, clinical information and severity scores were recorded. Data collected included serum Fol and B12 levels using the DxI® Autoanalyzer (Beckman Coulter) based on a competitive electrochemoluminescence immunoassay. Results: mean serum Fol was within the reference range stipulated by the laboratory on the first day. Nevertheless, a total of 21.4 % of the patients had high Fol levels, with 14.2 % being Fol deficient. An association was observed between Fol (p ˂ 0.012) status and 28-day mortality, and the number of days of mechanical ventilation, fraction of inspired oxygen (FiO2) and fibrinogen increased in patients with higher Fol levels (p ˂ 0.05). In addition, 85.7 % of cases had B12 levels above the reference values, with a correlation being observed between B12 and Fol. Conclusions: this study proposes Fol as a novel morbidity-mortality biomarker in critical septic patients, and reinforces the usefulness of B12 as a morbidity biomarker. It is thus suggested that the measurement of Fol upon admission and over the first 72 hours of hospital stay could provide prognostic information about the clinical course and outcome of septic shock patients.