INTRODUCTION: In ICU the need for acute renal replacement therapy (RRT) associates with high mortality and risk of end-stage renal disease (ESRD), but there are limited long-term data. We investigated these outcomes and their risk factors.

METHODS: Retrospective analysis of all adult patients admitted to a general, university hospital ICU 2005-2012, excluding chronic dialysis patients. ESRD was defined as need of RRT > 90 days or kidney transplant.

RESULTS: Of 5766 patients included, 1004 (16%) received acute RRT; their 30-day mortality was 42% vs. 16% for those not requiring acute RRT (adjusted hazard ratio (HR) 1.13 (0.96-1.32)). The 90-day mortality was 55% for patients receiving acute RRT vs. 22% for those who did not (adjusted HR 1.32 (1.15-1.51)) and 1-year mortality was 63% vs. 30%, respectively, (adjusted HR 1.31 (1.16-1.48)). The 7-year risk of ESRD for ICU patients surviving 90 days was 10% for patients who received acute RRT vs. 0.5% among those who did not (adjusted HR 5.9 (2.9-12.4)). Independent risk factors for ESRD included pre-existing kidney disease, pre-existing peripheral vascular disease and use of acute RRT in ICU.

CONCLUSIONS: The need of acute RRT was associated with markedly increased long term risk of death and ESRD; in contrast its use was not associated with 30-day mortality. In addition to acute RRT, decreased kidney function and peripheral vascular disease before ICU admission were risk factors for ESRD. It seems warranted offering medical follow-up to patients after acute RRT in ICU.