Overall outcomes of acute kidney injury

This chapter describes the overall short- and long-term, mainly non-renal outcomes of patients who suffer from acute kidney injury (AKI). Despite increasing age and greater burden of co-morbidity at the occurrence of AKI, patient mortality shows an overall decline over time. However, relatively ‘mild’ forms of AKI (i.e. defined as an absolute increase in serum creatinine of at least 0.3 mg/dL (26.4 µmol/L)) are associated with statistically significant decreased patient survival. The absolute mortality rates of AKI vary according to the different patient groups studied (intensive care unit, hospital, and population based), differences in parameters used for the criteria of AKI, differences in acquisition of baseline serum creatinine, differences between need of renal replacement therapy or not, and timing of endpoints (in-hospital mortality, 30 days, 60 days, or longer). In many instances, particularly in critically ill patients, AKI occurs in the setting of other diseases, such as sepsis, which are associated with a significant mortality risk. In such cases, AKI appears to amplify the risk of death associated with the underlying disease.