Red Cell Distribution Width at Admission Predicts The Frequency of Acute Kidney Injury and 28-Day Mortality in Patients With Acute Respiratory Distress Syndrome.

Objectives To determine the association of red cell distribution width (RDW) at admission with frequency of acute kidney injury (AKI) and 28-day mortality in acute respiratory distress syndrome (ARDS) patients. Methods 258 ARDS patients were investigated in retrospective and prospective studies. The primary outcome was frequency of AKI. The secondary outcome was 28-day mortality. Results The retrospective study included 193 ARDS patients, of which 67 (34.7%) were confirmed AKI and 76 (39.4%) died within 28 days. The RDW level in the AKI group was significantly higher than in the non-AKI group [(15.15 +/- 2.59) % vs. (13.95 +/- 1.89) %]. Increased RDW was a significant predictor of frequency of AKI (OR:1.247, 95% CI: 1.044,1.489). The area under the ROC curve of RDW for predicting AKI was 0.687 (95% CI: 0.610, 0.764) and the cut-off value was 14.45 (sensitivity, 56.7%; specificity, 72.8%). In addition, the proportion of patients with RDW >= 14.45% in the non-survival group was notably higher compared with the survival group (48.7% vs.29.1%). Furthermore, cox regression analysis revealed that RDW >= 14.45% was associated with 28-day mortality (HR:1.817, 95% CI: 1.046, 3.158), while Kaplan-Meier analysis showed patients with RDW >= 14.45% had a significantly lower survival rate than those with RDW = 14.45% group significantly higher than in RDW < 14.45%. Conclusion RDW was a significant, independent predictor for frequency of AKI and 28-day mortality in ARDS patients.