A retrospective multicenter, observational design intended to capture data on pediatrics (weighing between 8 - 20 kg) who underwent continuous renal replacement therapy (CRRT) using the HF20 set. Data will be compared with a similar population (weighting 8-20 kg) from the ppCRRT registry who received CRRT with Prismaflex M60 sets.

This study aims to compare patient outcomes after treatment with HF20 based CRRT to the historical ppCRRT registry. Data from eligible patient records will be collected, starting from January 2008 to most recent in Canada and from January 2020 to most recent in the US.

The ppCRRT registry used a prospective observational format whereby de-identified data on patients and CRRT circuits were collected from 13 participating centers across the US between 2001 JAN 01 and 2005 AUG 31. The registry's primary outcome measure was patient survival to ICU discharge.

Inclusion Criteria:

1. Patient weighed between 8 and 20 kg (17.6 - 44.1 lb).
2. Patient received medical care in an intensive care unit (ICU) and was treated with HF20 based CRRT.
3. Patient had a clinical diagnosis of AKI or ARF or fluid overload requiring CRRT.

Note: The cohort of patients treated with M60 sets from the ppCRRT registry (weighing 8 - 20 kg) are to meet inclusion criteria 1 and 3.

Exclusion Criteria:

There are no exclusion criteria for this study.

Data from approximately 40 pediatric patients who had acute kidney injury (AKI), acute renal failure (ARF) or fluid overload requiring CRRT, weighed between 8 and 20 kg (17.6-44.1 lb), and were treated in the ICU with marketed HF20 based CRRT between 2008 to current in Canada or with HF20 product available under EUA between 2020 to current in the US, will be collected.

Data will be compared with a similar population (weighing 8-20 kg) from the ppCRRT registry who received CRRT with Prismaflex M60 sets.