A Comparison of the Commonly Used Surrogate Markers for Citrate Accumulation and Toxicity during Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation

Optimizing Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation: Insights from the ORCA Trial-A Retrospective Study on 10 Years of Practice

(1) Background: Citrate is preferred in continuous renal replacement therapy (CRRT) for critically ill patients because it prolongs filter life and reduces bleeding risks compared to unfractionated heparin (UFH). However, regional citrate anticoagulation (RCA) can lead to acid-base disturbances, citrate accumulation, and overload. This study compares the safety and efficacy of citrate-based CRRT with UFH and no anticoagulation (NA) in acute kidney injury (AKI) patients. (2) Methods: A retrospective analysis was conducted on adult patients (≥18 years) who underwent CRRT from July 2010 to June 2021 in an intensive care unit. (3) Results: Among 829 AKI patients on CRRT: 552 received RCA, 232 UFH, and 45 NA. The RCA group had a longer filter lifespan compared to UFH and NA (56 h [IQR, 24-110] vs. 36.0 h [IQR, 17-63.5] vs. 22 h [IQR, 12-48]; all Padj < 0.001). Bleeding complications were fewer in the RCA group than in the UFH group (median 3 units [IQR, 2-7 units] vs. median 5 units [IQR, 2-12 units]; Padj < 0.001) and fewer in the NA group than in the UFH group (median 3 units [IQR, 1-5 units] vs. 5 units [IQR, 2-12 units]; Padj = 0.03). Metabolic alkalosis was more common in the RCA group (32.5%) compared to the UFH (16.2%) and NA (13.5%) groups, while metabolic acidosis persisted more in the UFH group and NA group (29.1% and 34.6%) by the end of therapy vs. the citrate group (16.8%). ICU mortality was lower in the RCA group (52.7%) compared to the UFH group (63.4%; Padj = 0.02) and NA group (77.8%; Padj = 0.003). (4) Conclusions: Citrate anticoagulation outperforms heparin-based and no anticoagulation in filter patency, potentially leading to better outcomes through improved therapy effectiveness and reduced transfusion needs. However, careful monitoring is crucial to limit potential complications attributable to its use.

Safety of Citrate Anticoagulation in CKRT: Monocentric Experience of a Dynamic Protocol of Calcium Monitoring

Regional Citrate Anticoagulation (RCA) is considered the first-line anticoagulation for Continuous Kidney Replacement Therapy (CKRT). The RCA requires strict protocols and trained staff to avoid unsafe use and ensure its benefit. We have analyzed all our CKRT prescriptions from December 2020 to April 2022 anonymously, collecting data on CKRT, lab tests, clinical conditions, and complications of RCA. In addition, in order to better detect citrate accumulation, we have performed an RCA protocol by reducing the CaTot/Ca2+ ratio cut-off from 2.50 to 2.40 and increasing the number of calcium checks according to its trend. Among the 374 patients in CKRT, 104 received RCA prescriptions, of which 11 (10.6%) were discontinued: 4 for the suspicion of citrate accumulation, 1 for the development of metabolic alkalosis, 1 for the shift to a different CKRT procedure due to the need for a higher bicarbonate dose, 4 for the elevation of hepatocytolysis indexes, and 1 due to a preemptive discontinuation following massive post-surgery bleeding. None of the patients have had citrate toxicity as indicated by a CaTot/Ca2+ greater than 2.50, and our protocol has allowed the early identification of patients who might develop clinical citrate toxicity.

Management of regional citrate anticoagulation for continuous renal replacement therapy: guideline recommendations from Chinese emergency medical doctor consensus

Continuous renal replacement therapy (CRRT) is widely used for treating critically-ill patients in the emergency department in China. Anticoagulant therapy is needed to prevent clotting in the extracorporeal circulation during CRRT. Regional citrate anticoagulation (RCA) has been shown to potentially be safer and more effective and is now recommended as the preferred anticoagulant method for CRRT. However, there is still a lack of unified standards for RCA management in the world, and there are many problems in using this method in clinical practice. The Emergency Medical Doctor Branch of the Chinese Medical Doctor Association (CMDA) organized a panel of domestic emergency medicine experts and international experts of CRRT to discuss RCA-related issues, including the advantages and disadvantages of RCA in CRRT anticoagulation, the principle of RCA, parameter settings for RCA, monitoring of RCA (mainly metabolic acid-base disorders), and special issues during RCA. Based on the latest available research evidence as well as the paneled experts' clinical experience, considering the generalizability, suitability, and potential resource utilization, while also balancing clinical advantages and disadvantages, a total of 16 guideline recommendations were formed from the experts' consensus.

Analysis of the extracorporeal anticoagulation effect of modified citrate infusion during continuous renal replacement therapy in critically ill patients

INTRODUCTION

To analyze the anticoagulation effect of different local infusion methods of citrate underwent continuous renal replacement therapy (CRRT) in critically ill patients.

METHODS

The study adopted a single-centre retrospective design. Critically ill patients were divided into conventional group and modified group based on the infusion methods of citrate.

RESULTS

The modified group had a longer mean treatment time (67.67 ± 18.69  hours vs. 52.11 ± 24.26 hours, p = 0.007), a lower transmembrane pressure (147.77 ± 66.85 cm H₂ O vs. 200.63 ± 118.66 cm H₂ O, p = 0.038), fewer citrate bag replacements (1.43 ± 0.50 times vs. 10.60 ± 3.19 times, p < 0.001), and more steady ionized calcium at the venous end (0.35 ± 0.06 mmol/L vs. 0.40 ± 0.05 mmol/L, p = 0.006) compared to the conventional group patients, with statistically significant differences. The incidences of citrate accumulation and tubing coagulation were marginally lower in the modified group.

CONCLUSION

The modified local citrate infusion method can prolong treatment time, while reducing both the nursing workload and the occurrence of citrate accumulation.