Red cell distribution width (RDW) is a convenient and inexpensive measurement of the variation in the size of the erythrocyte and an index of its heterogeneity commonly used in combination with different laboratory tests for the differential diagnosis of hematological system diseases, iron deficiency anemia, and bone marrow dysfunction [1]. The detection of an RDW value below the standard reference value is infrequent and clinically meaningless, whereas values above the normal range mirror the presence of anisocytosis, probably attributable to the presence of small and large red blood cells (RBCs), or both [2]. Recent evidence suggests that RDW values are commonplace in patients with various disorders, especially in those with the most prevalent conditions such as diabetes, cardiovascular diseases (CVDs), infection, and cancer [3]. The value of RDW is now being regarded as a strong and independent risk factor for mortality in the general population [4]. Although it has not been definitely shown whether an increased level of RDW is a risk factor or an epiphenomenon of an underlying biological and metabolic imbalance as an innocent bystander, it seems reasonable to suggest that the assessment of this parameter should be broadened far beyond the differential diagnosis of anemia and should now be regarded as a “non”-innocent bystander [3, 4]. This review provides some general information about RDW, its routine assessment, and potential clinical application. Sepsis is a life-threatening clinical condition that has cost humanity heavily since time immemorial. This clinical syndrome has been found to have increasing incidence throughout the world in recent decades [5,6] Initially, sepsis was defined as systemic inflammatory response to infection, noting that multiple noninfectious causes could elicit the similar response.[5,6,7] In 2001, a second consensus panel expanded the list of variables for defining sepsis including organ dysfunction parameters as well [8]. Severity of illness and mortality risk escalates with severity of organ dysfunction. Severe sepsis and septic shock carry high potential mortality rates, possibly up to 40%–50% [6]. Prognostication in severe sepsis may facilitate aggressive management of particular patient groups. Prognostic factors such as age, sex, comorbidities, biomarkers (C-reactive protein [CRP], procalcitonin, etc.,), and severity of illness score (Acute Physiology and Chronic Health Evaluation [APACHE], etc.,) have been reported to be associated with the outcome in cases of severe sepsis [9,10,11].

Red cell distribution width (RDW) represents the variation in size of all the red blood cells (RBCs) in an individual patient. It is elevated when excess of reticulocytes are released into the circulation. Over and above its role in the evaluation of anemia, RDW has been found to be an important prognostic marker in the patients with cardiovascular disorders, pulmonary embolism, community-acquired pneumonia, and critical illness [12,13,14,15]. The association was independent of covariates such as nutritional status, anemia, other inflammatory markers, and comorbidities. Inflammation and oxidative stress have been suggested to reduce RBC survival and suppress their maturation resulting in release of large premature RBCs into circulation, contributing to elevated RDW [15,1,6,17]. Inflammation and oxidative stress are the essential components of sepsis cascade [6]. Complete blood count (CBC) is nowadays done in most of the sepsis patients admitted to the emergency medical services by automated analyzers all over the world. RDW is routinely provided within the CBC done by automated analyzers. Inexpensive, routinely available, and rapidly measurable prognostic tools have clinical utility in the identification of subset of patients with severe sepsis who need aggressive management. RDW could be a useful tool in prognostication of cases with severe sepsis as described in recent studies [18,1,9,20].

AIMS AND OBJECTIVE     To evaluate the prognostic value of RDW and compare it with the APACHE II score in patients having sepsis

MATERIAL AND METHODS

Study  was  a  hospital  based  prospective  observational study  conducted  from  October  2025  to  March  2026.  Seventy four Patients admitted with sepsis who presented to the inpatient department (IPD), High Dependency Unit (HDU), and Intensive Care Unit (ICU) of Madhubani Medical College and Hospital, Madhubani, Bihar, India who met the inclusion criteria were studied.

INCLUSION CRITERIA:

Patients  admitted  to  Intensive  Care  Units who  met the   criteria   of   sepsis   and   septic   shock According to International  Guidelines  for  Management  of  Sepsis

EXCLUSION CRITERIA:

Patients  with  previous  history  of  diseases  primarily affecting  RBCs,  blood  loss  >10%  of  blood  volume, blood    product    transfusion    one    week    prior to admission,    use    of    drugs    known    to    change morphology  and  rheology  of  RBCs  and  pregnant patients were excluded from the study.

STATISTICAL ANALYSIS

Data was entered in MS excel and analyzed using SPSS version    17.    Descriptive    studies    of    mortality    and complications were analyzed and presented in terms of Percentages.  Chi-Square Test was used to compare the proportion   of   death   and   complications   between   the groups

RESULTS

Table 1 Age Distribution of Patients (n=74)

The mean age of patients is 41.65 ± 16.9 years. The majority of cases fall within the 41-50 years age group (32.4%), followed by 31-40 years (24.3%) and 51-60 by 17.5% respectively.

Table 2: Distribution of Patients by RDW Values

Majority of Patients in Higher RDW Categories: Most patients (84.7%) have RDW values greater than 16%, with the largest group being those with RDW > 19% (46.8% of patients). Elevated RDW values (>19%) may indicate underlying inflammation, nutritional deficiencies (e.g., iron, B12), or chronic disease

DISCUSSION

RDW is a measure of degree of RBC size variability. It is calculated as the SD in RBC size divided by the MCV. RDW values are determined by many factors. Elevation in RDW has been shown to be associated primarily with conditions that lead to ineffective production or increased destruction of RBC. Sepsis syndrome influences erythropoiesis through various mechanisms. Elevated inflammatory markers (tumor necrosis factor α, interleukin 6, interleukin 1β, etc.) affect the RBC survival and maturation. Early release of immature, larger RBCs into the circulation results in elevated RDW. Pro-inflammatory state in sepsis syndrome also leads to decreased erythropoietin production, resistance to its effect, as well as decreased iron bioavailability. Erythroid precursor activity is thus suppressed in the bone marrow [20,21, 22, 23] Oxidative stress may also be a contributor for RDW-mortality association in sepsis. Elevated RDW is seen in states of high oxidative stress. It occurs by decreased RBC survival and release of large premature RBCs into circulation [24]. Raised RDW group had significantly higher percentage of patients with anemia and renal dysfunction. There are many studies examining the association of high RDW values with in/out-of-hospital mortality in different populations, concluding that a high value of RDW is a strong and independent predictor of mortality. Researchers suggested that the use of this parameter as an inexpensive prognostic marker in addition to other scores such as APACHE improves the prognostication of patients, especially critically ill ones {7,57,-59/ 25, 26-28].

CONCLUSION

This study highlights key clinical and demographic factors that influence sepsis outcomes. Advanced age, hypotension, tachycardia, elevated PCT, creatinine, and inflammatory markers were associated with higher mortality. The APACHE 2 score and RDW emerged as critical predictors of sepsis prognosis, with higher values significantly correlating with poor outcomes. Early identification of these risk factors, coupled with timely and aggressive management, is essential to improving survival rates in sepsis patients. Further research should focus on targeted interventions and refining prognostic models to enhance the clinical management of sepsis.

REFERENCES

1. Alcaíno H, Pozo J, Pavez M, Toledo H. Red cell distribution width as a risk marker in patients with cardiovascular diseases. Rev Med Chil. 2016;144(5):634–642. doi: 10.4067/S0034-98872016000500012.
2. Montagnana M, Cervellin G, Meschi T, Lippi G. The role of red blood cell distribution width in cardiovascular and thrombotic disorders. Clin Chem Lab Med. 2012;50:635–641. doi: 10.1515/cclm.2011.831.
3. Lippi G, Mattiuzzi C, Cervellin G. Learning more and spending less with neglected laboratory parameters: the paradigmatic case of red blood cell distribution width. Acta Biomed. 2017;87(3):323–328.
4. Salvagno GL, Sanchis-Gomar F, Picanza A, Lippi G. Red blood cell distribution width: A simple parameter with multiple clinical applications. Crit Rev Clin Lab Sci. 2015;52(2):86–105. doi: 10.3109/10408363.2014.992064. DOI: [DOI] [P
5. Mayr FB, Yende S, Angus DC. Epidemiology of severe sepsis. Virulence. 2014;5:4–11. doi: 10.4161/viru.27372. 
6. Angus DC, van der Poll T. Severe sepsis and septic shock. N Engl J Med. 2013;369:840–51. doi: 10.1056/NEJMra1208623. 
7. Bone RC, Sibbald WJ, Sprung CL. The ACCP-SCCM consensus conference on sepsis and organ failure. Chest. 1992;101:1481–3. doi: 10.1378/chest.101.6.1481. 
8. Levy MM, Fink MP, Marshall JC, Abraham E, Angus D, Cook D, et al. 2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference. Crit Care Med. 2003;31:1250–6. doi: 10.1097/01.CCM.0000050454.01978.3B. 
9. Afessa B, Keegan MT, Mohammad Z, Finkielman JD, Peters SG. Identifying potentially ineffective care in the sickest critically ill patients on the third ICU day. Chest. 2004;126:1905–9. doi: 10.1378/chest.126.6.1905. 
10. Annane D, Bellissant E, Cavaillon JM. Septic shock. Lancet. 2005;365:63–78. doi: 10.1016/S0140-6736(04)17667-8. 
11. Marshall JC, Reinhart K. International Sepsis Forum. Biomarkers of sepsis. Crit Care Med. 2009;37:2290–8. doi: 10.1097/CCM.0b013e3181a02afc. 
12. Hou H, Sun T, Li C, Li Y, Guo Z, Wang W, et al. An overall and dose-response meta-analysis of red blood cell distribution width and CVD outcomes. Sci Rep. 2017;7:43420. doi: 10.1038/srep43420. 
13. Zorlu A, Bektasoglu G, Guven FM, Dogan OT, Gucuk E, Ege MR, et al. Usefulness of admission red cell distribution width as a predictor of early mortality in patients with acute pulmonary embolism. Am J Cardiol. 2012;109:128–34. doi: 10.1016/j.amjcard.2011.08.015. 
14. Braun E, Domany E, Kenig Y, Mazor Y, Makhoul BF, Azzam ZS, et al. Elevated red cell distribution width predicts poor outcome in young patients with community acquired pneumonia. Crit Care. 2011;15:R194. doi: 10.1186/cc10355
15. Bazick HS, Chang D, Mahadevappa K, Gibbons FK, Christopher KB. Red cell distribution width and all-cause mortality in critically ill patients. Crit Care Med. 2011;39:1913–21. doi: 10.1097/CCM.0b013e31821b85c6. 
16. Pierce CN, Larson DF. Inflammatory cytokine inhibition of erythropoiesis in patients implanted with a mechanical circulatory assist device. Perfusion. 2005;20:83–90. doi: 10.1191/0267659105pf793oa. 
17. Lippi G, Targher G, Montagnana M, Salvagno GL, Zoppini G, Guidi GC, et al. Relation between red blood cell distribution width and inflammatory biomarkers in a large cohort of unselected outpatients. Arch Pathol Lab Med. 2009;133:628–32. doi: 10.5858/133.4.628. 
18. Jo YH, Kim K, Lee JH, Kang C, Kim T, Park HM, et al. Red cell distribution width is a prognostic factor in severe sepsis and septic shock. Am J Emerg Med. 2013;31:545–8. doi: 10.1016/j.ajem.2012.10.017. 
19. Wang F, Pan W, Pan S, Ge J, Wang S, Chen M, et al. Red cell distribution width as a novel predictor of mortality in ICU patients. Ann Med. 2011;43:40–6. doi: 10.3109/07853890.2010.521766. 
20. Kim CH, Park JT, Kim EJ, Han JH, Han JS, Choi JY, et al. An increase in red blood cell distribution width from baseline predicts mortality in patients with severe sepsis or septic shock. Crit Care. 2013;17:R282. doi: 10.1186/cc13145. 
21. Salvagno GL, Sanchis-Gomar F, Picanza A, Lippi G. Red blood cell distribution width: A simple parameter with multiple clinical applications. Crit Rev Clin Lab Sci. 2015;52:86–105. doi: 10.3109/10408363.2014.992064. 
22. Scharte M, Fink MP. Red blood cell physiology in critical illness. Crit Care Med. 2003;31:S651–7. doi: 10.1097/01.CCM.0000098036.90796.ED. 
23. Weiss G, Goodnough LT. Anemia of chronic disease. N Engl J Med. 2005;352:1011–23. doi: 10.1056/NEJMra041809. 
24. Kolls JK. Oxidative stress in sepsis: A redox redux. J Clin Invest. 2006;116:860–3. doi: 10.1172/JCI28111. 
25. Patel KV, Semba RD, Ferrucci L, Newman AB, Fried LP, Wallace RB, et al. Red cell distribution width and mortality in older adults: a meta-analysis. J Gerontol A Biol Sci Med Sci. 2010;65:258–265. doi: 10.1093/gerona/glp163
26. Patel KV, Ferrucci L, Ershler WB, Longo DL, Guralnik JM. Red blood cell distribution width and the risk of death in middle-aged and older adults. Arch Intern Med. 2009;169(5):515–523. doi: 10.1001/archinternmed.2009.11. DOI:
27. Safdar SA, Modi T, Sriramulu LD, Shaaban H, Sison R, Modi V, et al. The role of red cell distribution width as a predictor of mortality for critically ill patients in an inner-city hospital. J Nat Sci Biol Med. 2017;8(2):154–158. doi: 10.4103/0976-9668.210017. DOI:
28. Chu Y, Yuan Z, Meng M, Zhou H, Wang C, Yang G, et al. Red blood cell distribution width as a risk factor for inhospital mortality in obstetric patients admitted to an intensive care unit: a single centre retrospective cohort study. BMJ Open. 2017;7(6):e012849. doi: 10.1136/bmjopen-2016-012849. DOI: