MATERIALS AND METHODS
PD, hyperammonemia
FLUID OVERLOAD, RECRUITMENT, INBORN ERRORS OF METABOLISM, EDWARDS, HYPERAMMONEMIA
The setting was PICUs in six U.K. hospitals, with experience of performing RRT in babies. Children weighing 800 g to 8 kg requiring RRT for fluid overload or biochemical disturbance were recruited: babies with suspected inborn errors of metabolism leading to hyperammonemia were excluded as they require higher than normal dialysis clearances (We used a cluster-randomized cross-sectional stepped-wedge (SW) design with four periods and three sequences. The periods were each planned to last for 18 weeks: recruitment started in December 2018, but the trial did not close until August 2021 due to pauses in recruitment, largely related to the COVID-19 pandemic. Two sites (PICUs) were randomized to each of the sequences (details in We measured UF in the CVVH (Prismaflex [Baxter Healthcare, Deerfield, IL] and Aquarius [Edwards Lifesciences, Newbury, Berkshire, United Kingdom]) and NIDUS devices by timed weighings of fresh and waste fluid bags, and in manual PD by measuring the fluid volumes delivered and removed. Timed waste fluid and blood samples were collected to calculate biochemical clearances. Outcome measures are listed in Outcome MeasuresCVVH = continuous venovenous hemofiltration, RRT = renal replacement therapy.