The prognostic value of red blood cell distribution width in patients with suspected infection in the emergency department

Background: Sepsis is a potential life threatening dysregulated immune response to an infection, which can result in multi-organ failure and death. Unfortunately, good prognostic markers are lacking in patients with suspected infection to identify those at risk. Red blood cell distribution width (RDW) is a common and inexpensive hematologic laboratory measurement associated with adverse prognosis in multiple diseases. The aim of this study was to determine the prognostic value of RDW for mortality and early clinical deterioration in patients with a suspected infection in the emergency department. Methods: In this single center prospective observational cohort study, consecutive patients with suspected infection presenting for internal medicine in the emergency department between September 2016 and March 2018 were included. For prognostic validation of bedside sepsis scores and RDW receiver operating characteristics were generated. Association between RDW and mortality and ICU admission was analyzed univariate and in a multivariate logistic regression model. Results: 1046 patients were included. In multivariate analyses, RDW was significantly associated with 30-day mortality (OR 1.15, 95% CI: 1.04-1.28) and early clinical deterioration (OR 1.09, 95% CI: 1.00-1.18). For 30-day mortality RDW had an AUROC of 0.66 (95% CI 0.59-0.72). Optimal cut-off value for RDW 2 was 12.95%. For early clinical deterioration RDW had an AUROC of 0.59 (95% CI 0.54-0.63) with an optimal cut-off value of 14.48%. Conclusions: RDW was found to be a significant independent prognostic factor of 30-day mortality and early clinical deterioration in patients with suspected infection.. Therefore it can be a used as an extra marker besides bedside sepsis scores in identifying patients at risk for worse outcome in patients with suspected infection.