RESUMO
Objective To investigate the prognostic value of red cell distribution width (RDW) and relationship between RDW and severity of critical illness patients and prognostic role of RDW.Methods This was a prospective observational and diagnostic test study.From February 2011 to May 2013,196 medical patients in ICU were enrolled to study.Blood samples were taken within 24 hrs after admission to ICU for blood routine test and other chemical routine test,including RDW.Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score were also calculated.The patients were divided into survival group (n =126) and death group (n =70) based on their hospital outcomes.Differences in RDW levels and APACHE Ⅱ score between survival and death groups were compared with One-way ANOVA.The correlation between RDW and APACHE Ⅱ score were analyzed by Spearman correlation test.Receiver operator curve (ROC) test was used to determine the predictive value of RDW and APACHE Ⅱ for hospital death.Results Both RDW level and APACHE Ⅱ score were significantly higher in death group than those in survival group,whichwere (13.35 ±2.21) vs.(11.34 ±1.32) and (20.43 ±6.41) vs.(13.94 ±6.77) respectively (both P ＜ 0.01).RDW significantly correlated with APACHE Ⅱ score (r =0.309,P ＜0.01).To predict hospital death area under curve (AUC) of ROC curve by RDW and APACHE Ⅱ score were 0.792 (0.725,0.860) and 0.754 (0.686,0.822) respectively.The best cut-off value was determined by Yoden Index were 12.35 for RDW and 17.5 for APACHE Ⅱ score.The Accuracy of prediction was 76.5％ and 70.4％ respectively.In addition,all the 12 paticnts whose RDW level ＞ 15.4 were dead.Conclusion RDW level at admission to ICU correlate well with the severity of critical illness.RDW level has an additional predictive value for the prognosis of critical ill patients.
