Long-term risk of sepsis among survivors of acute kidney injury.

Many prior studies have shown that, in critically ill patients, acute kidney injury (AKI) commonly occurs in association with sepsis and its presence portends an increased likelihood of poor outcomes. In contrast, few studies have focused specifically on the influence of AKI on the long-term risk of developing sepsis. In a previous issue of Critical Care, a population-based cohort study by Lai and colleagues reported a long-term increased risk of severe sepsis for patients surviving beyond 90 days following hospitalization with an episode of AKI requiring renal replacement therapy. While the pathophysiologic mechanisms that underpin this finding remain to be elucidated and causality cannot be proven, this study suggests that severe AKI confers long-term susceptibility to infection and focuses further attention on the critical importance of long-term surveillance for survivors of severe AKI. Further mechanistic and clinical studies are required to more precisely define the extent and duration of any increased risk of severe sepsis beyond which a need for ongoing renal replacement therapy following AKI might be associated. Nonetheless, this novel study by Lai and colleagues could lead to a number of important new avenues for clinical inquiry, such as whether it might be possible to identify those most susceptible to severe sepsis after AKI and, ultimately, whether such episodes might be preventable.