Predictive Value of Red Cell Distribution Width at Admission as A Marker Of ICU Requirement in COVID-19 Infection

ABSTRACT

Introduction: COVID-19 is a global pandemic disease first identified in Wuhan, China in late 2019. As of March 2022, over 450 million cases and 6 million deaths have been reported across the world, with the confirmed numbers probably being a fraction of the real numbers. Red Cell Distribution width (RDW) is a measure of anisocytosis, that is, variation in the circulating red blood cell volume. It is a nonspecific marker of acute illness. Increased RDW is suggestive of dysfunctional erythropoiesis and/or shortened RBC lifespan. Hence, it is a good predictor of clinical outcome in many disorders. Aims & Objectives: AIMS: To prove association of RDW with COVID-19 infection requiring ICU stay in a tertiary care hospital. OBJECTIVE(S) Primary Objective: To assess the predictive value of RDW on admission with requirement of ICU as a marker of severity in COVID-19 patients. Secondary Objectives: To compare RDW to other markers commonly used in COVID-19 infection, such as D-Dimer and CRP. Material(s) and Method(s) Patients over 18 years of age getting admitted at COVID ward or ICU at P.D. Hinduja Hospital, Mumbai were included in the study. RDW, CRP and D-dimer values of Ward group and ICU group patients were noted and compared. Result(s) 234 patients were screened and 190 patients were included in the final study. RDW was found to have significant association with ICU requirement (p = 0.0066). Further, an RDW value of 13 or more is found to be 85% sensitive for predicting ICU requirement. RDW of 16 or more is found to be 80% specific for predicting requirement of ICU stay. Regarding secondary objectives, RDW was found to have significant correlation with D-Dimer (p = 0.0005) but not with CRP (p = 0.12). Conclusion(s) RDW can be a potentially useful marker for risk stratification in COVID-19. A value of RDW more than 16 is associated with a significant risk of ICU requirement in COVID-19 disease. Further studies may be indicated to find a statistically significant correlation between RDW values and mortality in COVID- 19.