Mortality and serum hepcidin are associated with persistent and transient acute kidney injury in septic patients

PURPOSE Acute kidney injury (AKI) is a common complication of sepsis and has high mortality. The 2017 Acute Disease Quality Initiative (AQDI) workgroup proposed new definitions for AKI - transient AKI and persistent AKI; however, very little is known about the effect of transient and persistent septic AKI on short-term mortality among critically ill patients with sepsis. The purpose of this study was to assess the impact of persistent AKI on mortality and to evaluate whether serum hepcidin can predict the occurrence of persistent AKI in critically ill patients with sepsis. MATERIALS AND METHODS This prospective observational study was performed in a general hospital mixed surgical-medical ICU in Pudong, China. Consecutive adults with sepsis admitted to the ICU with absence of chronic kidney disease, renal transplant, and AKI were included. AKI was defined according to the KDIGO criteria and classified as transient (< 48-hour duration) or persistent (48-hour duration). Blood samples were obtained within 6 hours from when AKI was diagnosed. RESULTS A total of 90 patients with sepsis or septic shock were included in the analysis. 44 (48.89%) patients developed AKI during ICU stay: 20 (45.45%) had transient and 24 (54.55%) had persistent AKI. Persistent AKI has a higher mortality than transient AKI (66.7 vs. 30.0%, p = 0.002). Persistent AKI and sequential organ failure assessment (SOFA) scores were an independent predictor of 60-day mortality. Patients with persistent AKI had higher concentrations of serum creatinine (SCr) and hepcidin than transient AKI patients when AKI was diagnosed. Logistic regression indicated that serum hepcidin was an independent predictor of persistent AKI in septic patients, with a fairly predictive value (AUC 0.71, 95% CI: 0.47 - 0.87; p = 0.02). CONCLUSION Persistent AKI was associated with increased 60-day mortality compared with transient AKI in septic patients. The serum hepcidin levels measured when AKI was diagnosed have a fair predictive value to predict the occurrence of persistent AKI in septic patients.