Kidney function decline after a non-dialysis-requiring acute kidney injury is associated with higher long-term mortality in critically ill survivors
Department of Nephrology and Renal Transplantation, Hospital de Santa Maria, Centro Hospitalar de Lisboa Norte, EPE, Av. Prof. Egas Moniz, 1649-035 Lisboa, Portugal
Critical Care 2012, 16:467 doi:10.1186/cc11860
See related research by Lai et al., http://ccforum.com/content/16/4/R123Published: 29 November 2012
First paragraph (this article has no abstract)
In a recent issue of Critical Care, we read with interest the article by Lai and colleagues  in which they retrospectively analyzed the association between kidney function decline after a non-dialysis-requiring acute kidney injury (AKI) and long-term mortality (median follow-up of 700 days) in 634 intensive care unit (ICU) survivors. The authors found that every 1 mL/minute per 1.73 m2 decrease from baseline-estimated glomerular filtration rate of individuals who progressed to stage 3, 4, and 5 chronic kidney disease significantly increased the risks of mortality by 0.7%, 2.3%, and 4.1%, respectively. This observation is novel and suggests that a gradual decline in long-term renal function in non-dialysis-requiring AKI survivors is associated with decreased survival. Curiously, the authors have not evaluated the impact of sepsis on renal function and mortality. Sepsis is the most common cause of AKI in the ICU, and patients with septic AKI are clinically distinct from those with non-septic AKI [2-4]. First, septic AKI is associated with a greater burden of illness, concomitant non-renal organ dysfunction, and need for mechanical ventilation and vasoactive therapy. Second, patients with septic AKI are less likely to have impaired premorbid kidney disease. Third, patients with septic AKI have longer hospital length of stay and increased hospital mortality. Lastly, patients with septic AKI are more likely to recover kidney function by hospital discharge. Therefore, the discrimination of septic and non-septic AKI may have clinical relevance for clinicians, and sepsis should be taken into consideration in analyzing not only short-term outcomes but also long-term renal function and long-term mortality in critically ill survivors of AKI.