The utility of red cell distribution width to predict mortality of septic patients in a tertiary hospital of Nepal

Abstract

Background: Sepsis is a common problem encountered in the emergency room which needs to be intervened early. Predicting prognosis is always a difficult task in busy emergency rooms using present scores, which has several variables to calculate. Red cell distribution width (RDW) is an easy, cheap, and efficacious score to predict the severity and mortality of patients with sepsis.Methods: This prospective analytical study was conducted in the emergency room of Tribhuvan University Teaching Hospital among the patients age ≥16 years and with a clinical diagnosis of sepsis using qSOFA score. 148 patients were analyzed in the study by using a non-probability purposive sampling method. Results: RDW has fair efficacy to predict the mortality in sepsis (Area under the Curve of 0.734; 95% C. I= 0.649-0.818; p-value=0.000) as APACHE II (AUC of 0.728; 95% C. I= 0.637 to 0.819; p-value=0.000) or SOFA (AUC of 0.680, 95% C.I =0.591-0.770; p-value=0.001). Youden Index was maximum (37%) at RDW value 14.75, which has a sensitivity of 83% (positive likelihood ratio=1.81) and specificity of 54% (negative likelihood ratio=0.32). Out of 44 patients with septic shock 16 died (36.4 %) and among 104 patients without septic shock, 24 died (22.9%) which had the odds ratio of 0.713 (p=0.555, 95% C. I= 0.231-2.194). Overall mortality was 27.02% (n=40). RDW group analysis showed no mortality in RDW <13.1 group, 3.6% mortality in 13.1 to 14 RDW group, 22.0% mortality in 14 to >15.6 RDW group and 45.9% mortality in >15.6 RDW group. Significant mortality difference was seen in 14 to >15.6 and >15.6 RDW subgroups with a p-value of 0.003 and 0.008 respectively.Conclusion: Area under the curve value for RDW is fair enough to predict the mortality of patients with sepsis in the emergency room. It can be integrated with other severity scores (APACHE II or SOFA score) for better prediction of prognosis of septic patients.