Characteristics and outcomes of children ≤ 10 kg receiving continuous kidney replacement therapy: a WE-ROCK study

Background: Continuous kidney replacement therapy (CKRT) is often used for acute kidney injury (AKI) or fluid overload (FO) in children ≤ 10 kg. Intensive care unit (ICU) mortality in children ≤ 10 kg reported by the prospective pediatric CRRT (ppCRRT, 2001–2003) registry was 57%. We aimed to evaluate characteristics associated with ICU mortality using a contemporary registry. Methods: The Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK) registry is a retrospective, multinational, observational study of children and young adults aged 0–25 years receiving CKRT (2015–2021) for AKI or FO. This analysis included patients ≤ 10 kg at hospital admission. Primary and secondary outcomes: ICU mortality and major adverse kidney events at 90 days (MAKE-90) defined as death, persistent kidney dysfunction, or dialysis within 90 days, respectively. Results: A total of 210 patients were included (median age 0.53 years (IQR, 0.1, 0.9)). ICU mortality was 46.5%. MAKE-90 occurred in 150/207 (72%). CKRT was initiated at a median 3 days (IQR 1, 9) after ICU admission and lasted a median 6 days (IQR 3, 16). On multivariable analysis, pediatric logistic organ dysfunction score (PELOD-2) at CKRT initiation was associated with increased odds of ICU mortality (aOR 2.64, 95% CI 1.68–4.16), and increased odds of MAKE-90 (aOR 2.2, 95% CI 1.31–3.69). Absence of comorbidity was associated with lower MAKE-90 (aOR 0.29, 95%CI 0.13–0.65). Conclusions: We report on a contemporary cohort of children ≤ 10 kg treated with CKRT for acute kidney injury and/or fluid overload. ICU mortality is decreased compared to ppCRRT. The extended risk of death and morbidity at 90 days highlights the importance of close follow-up. Graphical abstract: (Figure presented.)