Long-term outcome after acute kidney injury in critically-ill patients

Assessment of short-term outcome in critically-ill patients who develop acute kidney injury (AKI) may underestimate the true burden of disease. It is important to focus on long-term survival, renal recovery and quality of life beyond hospital discharge. Although the majority of critically-ill patients with AKI die during hospital stay, there is only a minor increase in mortality after hospital discharge among AKI patients treated in the intensive care unit (ICU). Estimates of mortality rates at 1 year following hospital discharge range from 57% to 78% with an absolute difference between hospital mortality and 1-year mortality ranging from 4% to 18%. Renal recovery is another important measure of outcome since chronic renal replacement therapy (RRT) does not only significantly affect health-related quality of life (HRQoL), it is also costly. Fortunately, renal recovery occurs in most AKI survivors leading to independence of RRT at 1 year following hospital discharge. Potential factors associated with reduced recovery of renal function are female sex, high comorbidity, older age, a parenchymal aetiology of AKI, late initiation of RRT, and use of intermittent haemodialysis (IHD). HRQoL in survivors of critical illness and severe AKI is perceived as acceptable and good, despite the fact that HRQoL scores are lower than these of the general population.