The association between the duration of postoperative acute kidney injury and in-hospital mortality in critically ill patients after non-cardiac surgery: an observational cohort study

AbstractObjectives: The severity of acute kidney injury (AKI) has been a well-known predictor for in-hospital mortality. Whether AKI duration could predict in-hospital mortality is not clear. This study determines the association between the in-hospital mortality and AKI duration in patients after non-cardiac surgery. Materials and methods: Surgical patients who were admitted to the ICU were enrolled. AKI cases were defined using KDIGO guidelines and categorized according to the tertiles of AKI duration (1st tertile: 2 days, 2nd tertile: 3–6 days and 3rd tertile: 7 days). The adjusted hazard ratios (HRs) for in-hospital mortality are compared to those without AKI. The predictability of mortality is accessed by calculating the area under the curve (AUC) for the receiver operating characteristic (ROC) curve. Results: From a total of 318 postoperative patients, 98 developed AKI (1st tertile: 34 cases, 2nd tertile: 30 cases and 3rd tertile: 34 cases) and 220 had no AKI. The in-hospital mortality rates are 6.8...