Background: We wished to determine the optimal duration of follow-up for patients with acute renal failure (ARF) treated with continuous renal replacement therapy (CRRT) and tested the hypothesis that a 6 month follow-up would be the minimum to catch most of the mortalities. In addition, we evaluated the association between mortality and the RIFLE classification in the same patients.
Methods: We analysed the data of 8152 consecutive patients who had been admitted to the intensive care unit (ICU) of a Swedish university hospital between 1995 and 2001. Of that population, 207 patients were treated with CRRT, excluding 16 treated for non-renal indications.
Results: ICU mortality in this cohort was 34.8% and 30 day and in-hospital mortalities were 45.9% and 50.2%, respectively. The cohort's all-cause mortality 6 months after inclusion was 59.9%, but 54.6% died as early as after 60 days. Patients in the more severe RIFLE category, F (failure), had a 30 day mortality of 57.9% compared with 23.5% for those in the RIFLE-R (risk) category and 22.0% for RIFLE-I (injury) patients.
Conclusions: In our opinion, a 60 day follow-up is sufficient to catch the majority of deaths in ARF patients treated with CRRT. The patients in the RIFLE-F category had a significantly higher mortality than RIFLE-R and -I patients.