PRACTICE PATTERNS AND PREDICTORS OF NET ULTRAFILTRATION RATE IN INTERMITTENT HAEMODIALYSIS FOR ACUTE KIDNEY INJURY: A SINGLE-CENTRE RETROSPECTIVE OBSERVATIONAL STUDY
Dr Lisa Paxton1, Mr Tom Larsen2, Dr Timothy Fazio2, Prof Nigel Toussaint1,3, Prof Rinaldo Bellomo4,5,6,7, Dr Emily See1,3,4,5
1Department of Nephrology, The Royal Melbourne Hospital , Parkville, Australia, 2Business Intelligence Unit, The Royal Melbourne Hospital , Parkville, Australia , 3Department of Medicine (RMH), University of Melbourne, Parkville, Australia , 4Department of Intensive Care, The Royal Melbourne Hospital, Parkville, Australia, 5Department of Intensive Care, Austin Hospital, Melbourne, Australia, 6Department of Critical Care, University of Melbourne, Melbourne , Australia , 7Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, Australia
Aim: Review of net ultrafiltration (NUF) in patients undergoing intermittent haemodialysis (IHD) for acute kidney injury (AKI)
Background: In patients receiving continuous renal replacement therapy (CRRT) for AKI, NUF rates >1.75 ml/kg/hr are associated with increased mortality and delayed recovery. There is no information on NUF rates in AKI patients undergoing IHD
Methods: We conducted a retrospective study of AKI patients treated with IHD at our centre between 2020 and 2023. The primary outcome was NUF rate (mL/kg/h). Secondary outcomes included mortality and renal recovery at 90 days (estimated glomerular filtration rate [eGFR], major adverse kidney events [MAKE], IHD dependence and days to liberation from IHD).
Results: 74 patients (median age 62 years [IQR 46-71], median baseline eGFR 81 mL/min/1.73m2 [IQR 71-96]). The median NUF rate was 5.58 mL/kg/h [IQR 4.72 to 7.96]. Older patients received lower NUF rates (β coefficient -0.07, 95% CI -0.10 to -0.03), as did patients with hypertension (β coefficient -1.60, 95% CI -2.83 to -0.37) or a lower baseline eGFR (β coefficient 0.04, 95% CI 0.01 to 0.08). No differences were seen in time to recovery or change in renal function at 90 days between high (≥5.58 mL/kg/h) and low (<5.58 mL/kg/h) NUF rate groups. By 90 days, 38 patients (54.3%) had developed a MAKE; most had a 25% reduction in eGFR (n=23, 31%), and 6 patients (8.1%) had died.
Conclusions: In AKI patients, the median NUF rate during IHD was 5.58 mL/kg/hr, but lower in the presence of older age, hypertension and lower pre-morbid eGFR. In this setting, at 90 days, MAKE was common, one third of patients had a >25% eGFR reduction, and one in 12 had died.