BACKGROUND: The optimal time to initiate renal replacement therapy (RRT) in intensive care unit (ICU) patients with acute kidney injury (AKI) is unclear. We examined the impact of early RRT on the long-term mortality and risk of chronic kidney disease (CKD) and end-stage renal disease (ESRD).
METHODS: This cohort study included all adult patients treated with continuous RRT in the ICU at Aarhus University Hospital, Skejby, Denmark (2005-2015). Data were obtained from a clinical information system and population-based registries. Early treatment was defined as RRT initiation at AKI stage 2 or below and late treatment as RRT initiation at AKI stage 3 at. Inverse probability of treatment (IPT) weights were computed from propensity scores. The IPT-weighted cumulative risks of CKD (eGFR<60 ml/min/1.73 m2), ESRD, and mortality was estimated and compared using an IPT-weighted Cox regression.
RESULTS: The mortality, CKD and ESRD analyses included 1,213, 303 and 617 patients, respectively. The 90-day mortality in the early RRT group was 53.6% compared to 46.0% in the late RRT group (hazard ratio [HR] = 1.24 [95% CI, 1.03-1.48]). The 90-day to 5-year mortality was 37.7% and 41.5% in the early and late RRT groups, respectively (HR = 0.95 [95% CI: 0.70-1.29]). The 5-year risk of CKD was 35.9% in the early RRT group and 44.9% in the late RRT group (HR = 0.74 [95% CI: 0.46-1.18]). The 5-year risk of ESRD was 13.3% in the early RRT group and 16.7% in the late RRT group (HR = 0.79 [95% CI: 0.47-1.32]).
CONCLUSION: Early initiation was associated with increased 90-day mortality. In patients surviving to day 90, early initiation was not associated with major impact on long-term mortality or risk of CKD and ESRD. Despite potential residual confounding due to the observational design, our findings do not support that early RRT initiation is superior to late initiation.
