Predictive value of red blood cell distribution width and platelet-to-lymphocyte ratio for acute kidney injury in critically ill patients.

OBJECTIVES: The purpose of this study was to explore the value of red blood cell distribution width (RDW) and platelet-to-lymphocyte ratio (PLR) in predicting the occurrence of acute kidney injury (AKI) in critically ill patients. MATERIALS AND METHODS: Among 1,500 adult patients in the intensive care unit (ICU) between January 2016 and December 2019, we examined the associations of baseline RDW and PLR with the risk of AKI development using logistical analysis. In addition, we explored the value of RDW and PLR in predicting in-hospital mortality. RESULTS: Overall, 615 (41%) patients were diagnosed with AKI. We divided the groups into two subgroups each; the high-RDW (≥ 14.045%) group had a high risk of developing AKI (OR = 5.189, 95% CI: 4.088 - 6.588), and the high-PLR (≥ 172.067) group had a risk of developing AKI too (OR = 9.11, 95% CI: 7.09 - 11.71). The areas under the receiver operating characteristic curves (AUCs) for the prediction of AKI incidence based on RDW and PLR were 0.780 (95% CI: 0.755 - 0.804) and 0.728 (95% CI: 0.702 - 0.754) (all p < 0.001), with cut-off values of 14.045 and 172.067, respectively. Moreover, a higher RDW was associated with a higher rate of hospital mortality (OR: 2.907, 2.190 - 3.858), and the risk of in-hospital mortality related to PLR was 1.534 (95% CI: 1.179 - 1.995). CONCLUSION: A higher RDW was related to a higher risk of AKI occurrence and in-hospital mortality in the ICU.