Red Cell Distribution Width As a Predictor of Mortality in Patients With Sepsis

Abstract

Introduction Sepsis is a common medical condition that is associated with very high mortality and, in survivors, long-term morbidity. Conventional inflammatory markers, such as CRP, erythrocyte sedimentation rate (ESR), and white blood cell count (WBC), have proven to have a limited utility in sepsis patients by virtue of their poor sensitivity and specificity for infections. Recently, the commonly used index of red cell distribution width (RDW) has been implicated as a prognostic marker in sepsis. This study aimed at assessing the role of RDW in predicting outcomes such as mortality in patients with sepsis and to study its role as a prognostic marker. Methods This was conducted as a prospective comparative observational study over a two year period between 2018 and 2020 in a tertiary care center in South India. In total, 60 adult patients above 18 years of age who were diagnosed to have severe sepsis and septic shock were selected to be part of the study. To find the survival probability on overall survival, Kaplan-Meier analysis was used and a comparison was done using the Log-rank test. To find the most significant predictors of mortality, cox regression analysis was applied. Results A total of 60 patients (n=60) were enrolled in this study out of which 30 (50%) patients had a rise in RDW and 30 (50%) patients had a fall in RDW. A total of 17 (28.3%) patients died during this study. In the rise in RDW group, there were 12 (40%) deaths while in the fall in the RDW group, there were five (16.7%) deaths. There was a statistically significant association found between mortality with rise and fall in RDW (p<0.05). A cox multivariate regression analysis demonstrated statistically significant associations between a rise in RDW (p<0.05, HR: 5.6, CI 1.4 to 21.9) and serum hemoglobin < 13.6 g/dL (p<0.05, HR: 3.6, CI 1.1 to 11.4) with mortality in this study. Kaplan-Meier analysis of rise and fall in RDW with survival trended towards better survival outcomes in the fall in the RDW group but was not significant (p=0.07). Conclusion We found that an increase in RDW from baseline during the initial 72 hours after admission is significantly associated with adverse clinical outcomes including mortality. The mortality in the rise in the RDW group, as well as overall mortality, were significantly higher than the mortality in the reduced RDW group. Hence, serial RDW measurements could be used as a prognostic factor in severe sepsis and septic shock.