Predictive factors of successful renal replacement therapy weaning : Deciding On patients Orientations after Renal...

Renal replacement therapy (RRT) is a life-saving intervention in severe acute kidney injury (AKI). After a clinician-initiated discontinuation, the likelihood of sustained liberation remains uncertain. We aimed to identify predictors of successful RRT weaning and to develop a pragmatic bedside tool (the UNDERSCORE) to support post-discontinuation management.

This post-hoc analysis of two multicenter randomized trials (AKIKI and AKIKI2) included ICU patients with KDIGO stage 3 AKI managed with a conservative initiation approach. Patients were eligible if they underwent an RRT weaning attempt, defined as discontinuation for ≥ 3 consecutive days. The primary outcome was successful weaning, i.e., no RRT resumption within seven days. Independent predictors were identified using multivariable logistic regression, and the resulting model (UNDERSCORE) was externally validated in an independent Swiss ICU cohort.

Among 554 patients who received RRT, 180 underwent a weaning attempt and 101 (56%) were successfully weaned. Six predictors were retained to construct the UNDERSCORE: RRT duration before the attempt, septic shock on admission, baseline serum creatinine, and three clinical variables assessed after the weaning attempt (use of vasopressors, invasive mechanical ventilation, and urine output). The score showed strong discrimination in the derivation cohort (AUC 0.86, 95% CI 0.80-0.91). In the external Swiss cohort (n = 415), 338 patients (81%) were successfully weaned, with fair performance across a broader case mix (AUC 0.73, 95% CI 0.66-0.80).

The UNDERSCORE, derived from a homogeneous conservative RRT initiation cohort and validated in a diverse ICU population, provides a bedside tool to estimate the probability of sustained RRT discontinuation after an initial clinician-initiated stop.