Abstract: FR-PO0107
Depletion of Uric Acid by Continuous Kidney Replacement Therapy
Session Information
- AKI: Epidemiology and Clinical Trials
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Lee, Seolhyun, Stanford University School of Medicine, Stanford, California, United States
- Vasquez Espinosa, William Andres, Stanford University School of Medicine, Stanford, California, United States
- Sirich, Tammy L., Stanford University School of Medicine, Stanford, California, United States
- Meyer, Timothy W., Stanford University School of Medicine, Stanford, California, United States
Background
Uric acid levels are commonly elevated in patients maintained on hemodialysis (HD) because HD provides a lower time-average uric acid clearance than the native kidney. Continuous kidney replacement therapy (CKRT) provides higher time-averaged clearances of small solutes than HD. We therefore examined whether the high clearance provided by CKRT would reduce plasma uric acid levels below normal.
Methods
Plasma uric acid and creatinine levels were measured in 12 patients before and at 2-4 days after initiation of CKRT. These solutes were also measured in 17 patients maintained on CKRT for a longer period of 5-110 days. CKRT dosing in both groups met current guidelines (effluent 28 ± 4 ml/kg/hr in patients initiating CKRT and 27 ± 3 ml/kg/hr in patients longer on CKRT). Solute removal rates were estimated from plasma levels and effluent flow rates.
Results
Initiation of CKRT rapidly reduced uric acid levels to an average value of 1.7 ± 0.6 mg/dl after 2 to 4 days. Longer term CKRT maintained uric acid levels at a the low average level of 1.7 ± 0.6 mg/dl. In comparison, initiation of CKRT reduced plasma creatinine from 4.2 ± 2.2 to 2.0 ± 1.0 mg/dl with a further reduction in plasma creatinine to 1.2 ± 0.4 mg/dl with longer term CKRT. The generation of uric acid estimated from its removal rate remained stable (890±342 mg/day at 2-4 days and 887±379 mg/day with longer CKRT) while creatinine generation declined significantly with prolonged severe illness (1043 ± 434 mg/day at 2-4 days and 560 ± 256 mg/day with longer term CKRT).
Conclusion
The high small solute clearance rates provided by CKRT reduced uric acid levels below the laboratory's minimum normal values (3.4 mg/dl male, 2.4 mg/dl female). We do not know whether this reduction of uric acid levels is harmful. However it has been posited that humans and other hominids obtain biologic advantages from having higher plasma uric acid levels than other species. The reduction of uric acid levels provides an example of possible excessive loss of small solutes by CKRT.