Abstract: TH-PO0529
Predicting Bicarbonate Trajectory and Risk of Citrate Accumulation in Critically Ill Patients Undergoing Continuous Kidney Replacement Therapy
Session Information
- Dialysis: Novel Therapeutics and Medication Management
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Müller, Mattia M, UniversitatsSpital Zurich, Zürich, ZH, Switzerland
- Hansel, Dietmar, Fresenius Medical Care Deutschland GmbH, Bad Homburg, HE, Germany
- Bachmann, Jasmin, UniversitatsSpital Zurich, Zürich, ZH, Switzerland
- Bartussek, Jan, UniversitatsSpital Zurich, Zürich, ZH, Switzerland
- Sazpinar, Onur, UniversitatsSpital Zurich, Zürich, ZH, Switzerland
- Pohlmeier, Robert, Fresenius Medical Care Deutschland GmbH, Bad Homburg, HE, Germany
- David, Sascha, UniversitatsSpital Zurich, Zürich, ZH, Switzerland
Group or Team Name
- The Zurich Critical Kidney Group.
Background
The process of restoring acid-base balance in patients undergoing continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) relies on the metabolic conversion of citrate to bicarbonate. However, individual variability in citrate metabolism can impede attaining target metabolic goals and increase the risk of citrate accumulation, particularly in critically ill patients. To support clinicians in optimizing treatment, we developed a bicarbonate prediction algorithm (BPA) to forecast the longitudinal trajectory of bicarbonate during CRRT. This study aimed to validate the BPA, identify confounders affecting its accuracy, and assess its potential as an early warning tool for detecting citrate accumulation in a time-critical manner using the deviation from its prediction.
Methods
This retrospective study included adult critically ill patients who underwent RCA-based CRRT at the University Hospital Zurich, Switzerland, between 2018 and 2023. Regression models and area under the ROC curve (AUC) were used to evaluate the accuracy of the prediction model, identify confounding factors, and determine threshold values for predicting citrate accumulation.
Results
A total of 612 critically ill patients with 18’657 bicarbonate predictions were analyzed. Mean age was 61±13 years, 29 % were female. Bicarbonate levels at CRRT start were 18±5 mmol/L. The mean difference between predicted and measured bicarbonate levels (ΔHCO3-) was -0.15±4.5 mmol/l. ΔHCO3- was associated with lactate, factor V, INR and AST plasma levels. Citrate accumulation was observed in 13% (80/612) of patients, occurring 14 ± 16 h after the initiation of CRRT. Longitudinal trajectories of ΔHCO3- effectively distinguished patients at risk of citrate accumulation from those without. A ΔHCO3- of 0.93 mmol/l measured 6h after onset of CRRT was detected as the most accurate risk estimator for citrate accumulation (AUC 0.76, 95%CI 0.68-0.83, sensitivity 0.76, specificity 0.65).
Conclusion
The developed algorithm accurately predicts the trajectory of bicarbonate levels over time in critically ill patients undergoing CRRT with RCA. It holds potential for bedside use to support individualized bicarbonate correction and to detect patients with citrate accumulation as early as possible.