Mortality and Cumulative Kidney Score are Associated with Transient and Persistent Acute Kidney Injury in Septic Patients: A Retrospective Study Based on MIMIC-IV

Background: Acute kidney injury (AKI) is frequently caused by sepsis. Recently, the Acute Disease Quality Initiative (ADQI) workgroup further classified AKI as transient or persistent. Oliguria and increased serum creatinine represent two different kinds of renal impairment. The aim of the study was to assess mortality and cumulative AKI score associated with transient and persistent AKI in septic patients.Methods: Septic patients were stratified according to the presence and AKI development (considered persistent when remaining >48 h) were included. An adjusted logistic regression model was used to determine hospital mortality. In addition, we calculated an AKI score by combining both Kidney Disease: Improving Global Outcomes (KDIGO) criteria of urine output and creatinine AKI stages. The relationship between the cumulative AKI score and persistent AKI was further examined using the logistic regression model and receiver operating characteristic (ROC) curve analysis.Results: 12928 septic patients were enrolled in the study. AKI occurred in 73.7% of septic patients, in 39.5% was transient and in 60.5% was persistent. Patients with persistent AKI had higher severity scores and more severe renal dysfunction upon admission. Persistent AKI, but not transient AKI, was associated with increased intensive care units (ICUs) and hospital mortality. Then we found that the cumulative AKI score was associated with an increased risk of persistent AKI. This association was consistent across three original KDIGO severity stages and subgroup analyses.Conclusions: It was found that persistent AKI was independently associated with mortality in septic patients. Furthermore, serum creatinine and urine output criteria had cumulative effects on KDIGO AKI staging and provided more information about the relationship between AKI and outcomes.