Four years on, ICU patients with kidney injury show high mortality and elevated urinary protein

The authors state, "Our study highlights the increased long-term risk of death associated with AKI treated with RRT in an ICU. Only one third of randomized patients were alive 3.5 years later, a lower survival than seen in recognised high mortality conditions such as the acute respiratory distress syndrome. Although, in our patients the risk of subsequent maintenance dialysis dependence is low, almost half have evidence of significant proteinuria, portending further risk in the years to come. These findings support the view that survivors of AKI are at increased risk and that closer surveillance may be justified. In addition, our findings suggest that chronic proteinuria reduction strategies, which have shown benefit in some patient groups with proteinuria, may warrant investigation as a therapeutic intervention."

A limitation is that the patients were enrolled in a randomized trial and therefore not necessarily representative of patients in ICUs with AKI in general, and not all patients agreed to long term follow up.

The authors conclude, "In a large cohort of patients with acute kidney injury randomized to differing doses of continuous renal replacement therapy in the ICU, the increased risk of death continues well beyond hospital discharge and is not altered by increased intensity of dialysis. The proportion of patients entering a maintenance dialysis program is small but there is a high prevalence of proteinuria amongst survivors suggesting significant ongoing risk of chronic kidney disease and mortality."