Red cell distribution width as a prognostic marker in mechanically ventilated children admitted in pediatric critical care unit of tertiary care centre, India

Swati M. Gadappa, Manas Kumar Behera


Background: Paediatric population is a vulnerable group necessitating standard care for medically and surgically ill children. Red cell distribution width (RDW) is a simple and low-cost measure that denotes the variability in red blood cell size. Any process that releases reticulocytes in the circulation will result in an increase in RDW. RDW may also be useful as a biomarker of disease severity and clinical outcomes in critically ill patients. 

Methods: Retrospective cohort study of all patients between 1month-12yrs of age, mechanically ventilated in Paediatric intensive care unit. Those patients with RDW on admission and complete data for PIM3 (Paediatric Index of Mortality 3) were included. Analyses included correlation, logistic regression analysis, and receiver operating characteristic (ROC) curves.

Results: Retrospective analysis of data on 93 consecutive critically ill children admitted in PICU was done between Jan 2015- June 2016. We noted statistically significant correlation between mortality and anemia (10.24 g/dL, SD 2.26; 8.78 g/dL, SD 2.60.p = 0.009), LOS on MV (p = 0.008), RDW (p = 0.002), shock (p = 0.004) and ventilator associated Pneumonia (p = 0.024).  Mortality increased as length of stay on mechanical ventilation increased (4.13 days, SD 2.125 versus 6.94 days, SD 7.603 p = 0.008). The cut-off of 18.10 was chosen as Mean RDW. Based on AUROC, RDW is independently associated with high risk of mortality.

Conclusions: RDW measured within 24 hours of PICU admission was independently associated with length of stay on mechanical ventilation and mortality in a general PICU population. We recommend the need for multicentric, prospective longitudinal studies to determine the optimum utility of RDW to enhance decision making in PICU.


Critical care outcome, Mechanical ventilation, RDW

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Qurtom HA, Al-Saleh QA, Lubani MM, Hassanein A, Kaddoorah N, Qurtom MA, et al. The value of red cell distribution width in the diagnosis of anaemia in children. Eur J Pediatr. 1998;148:745-8.

Yčas JW, Horrow JC, Horne BD. Persistent increase in red cell size distribution width after acute diseases: A biomarker of hypoxemia? Clin Chim Acta. 2015;448:107-17.

Bazick HS, Chang D, Mahadevappa K, Gibbons FK, Christopher KB. Red cell distribution width and allcause mortality in critically ill patients. Crit Care Med. 2011;39:1913-21.

Forhecz Z, Gombos T, Borgulya G, Pozsonyi Z, Prohászka Z, Jánoskuti L. Red cell distribution width in heart failure: Prediction of clinical events and relationship with markers of ineffective erythropoiesis, inflammation, renal function, and nutritional state. Am Heart J. 2009;158:659-66.

Lippi G, Targher G, Montagnana M, Salvagno GL, Zoppini G, Guidi GC. Relation between red cell distribution width and inflammatory biomarkers in a large cohort of unselected outpatients. Arch Pathol Lab Med. 2009;133:628-32.

Sipahi T, Koksal T, Tavil B, Akar N. The effects of acute infection on hematologic parameters. Ped Hemato Oncol. 2004;21:513-20.

Scharte M, Fink MP. Red blood cell physiology in critical illness. Crit Care Med. 2003;31:S651-7.

Dabbah S, Hammerman H, Markiewicz W. Relation between red cell distribution width and clinical outcomes after acute myocardial infarction. Am J Cardiol. 2010;105:312-7.

Pascual-Figal DA, Bonaque JC, Redondo B. Red blood cell distribution width predicts long-term outcome regardless of anaemia status in acute heart failure patients. Eur J Heart Fail. 2009;11:840-6.

van Kimmenade RR, Mohammed AA, Uthamalingam S. Red blood cell distribution width and 1-year mortality in acute heart failure. Eur J Heart Fail. 2010;12:129-36.

Tonelli M, Sacks F, Arnold M. Relation between red blood cell distribution width and cardiovascular event rate in people with coronary disease. Circ. 2008;117:163-8.

Braun E, Domany E, Kenig Y. Elevated red cell distribution width predicts poor outcome in young patients with community acquired pneumonia. Crit Care. 2011;15:R194.

Hampole CV, Mehrotra AK, Thenappan T. Usefulness of red cell distribution width as a prognostic marker in pulmonary hypertension. Am J Cardiol. 2009;104:868-72.

Patel KV, Ferrucci L, Ershler WB. Red blood cell distribution width and the risk of death in middle-aged and older adults. Arch Intern Med. 2009;169:515-23.

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 Series A Biomed Sci Med Sci. 2009;65(3):258-65.

Perlstein TS, Weuve J, Pfeffer MA. Red blood cell distribution width and mortality risk in a community-based prospective cohort. Arch Intern Med. 2009;169:588-94.

Büyükkoçak U, Gencay I, Ates G, Çağlayan O. Red blood cell distribution width and mortality in icu patients; a cross sectional retrospective analysis red blood cell distribution width and mortality in icu patients. Enliven: J Anesthesiol Crit Care Med. 2014;1(4):1-4.

Wang F, Pan W, Shuming P, Ge Junbo, Wang S, Chen M. Red cell distribution width as a novel predictor of mortality in ICU patients. Ann Med. 2011;43(1):40-6.

Hunziker S, Celi LA, Lee J, Howell MD. Red cell distribution width improves the simplified acute physiology score for risk prediction in unselected critically ill patients. Crit Care. 2012;16(3):R89.

Ramby AL, Goodman DM, Wald EL, Scott L. Weiss red blood cell distribution width as a pragmatic marker for outcome in paediatric critical illness. PLos One. 2015;10(6):e0129258.

ANZICS. PIM2 and PIM3 for the ANZPIC Registry Information Booklet. ANZICS. 2016. Available at

Weiss SL, Parker B, Bullock ME, Swartz S, Price C, Wainwright MS, et al. Defining pediatric sepsis by different criteria: Discrepancies in populations and implications for clinical practice. Pediatr Crit Care Med. 2012;13:e210-8.

Goldstein B, Giroir B, Randolph A. International pediatric sepsis consensus conference: definitions for sepsis and organ dysfunction in pediatrics. Pediatr Crit Care Med. 2005;6:2-8.

Sands KE, Bates DW, Lanken PN, Graman PS, Hibberd PL, Kahn KL, et al. Epidemiology of sepsis syndrome in 8 academic medical centers. JAMA. 1997;16:234-40.

Straney L, Clements A, Parslow RC, Pearson G, Shann F, Alexander J, et al. Paediatric index of mortality 3: an updated model for predicting mortality in pediatric intensive care. Pediatr Critical Care Med. 2013;14(7):673-81.

Ku NS, Kim H, Oh HJ, Kim YC, Kim MH, Song JE, et al. Red cell distribution width is an independent predictor of mortality in patients with Gram-negative bacteremia. Shock. 2012;38:123-7.

Lacroix J, Cotting J. Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network. Severity of illness and organ dysfunction scoring in children. Ped Crit Care Med. 2005;6:S126-34.