Safety and efficacy of regional citrate anticoagulation for continuous renal replacement therapy in liver failure patients: a systematic review and meta-analysis

PCRRT Expert Committee ICONIC Position Paper on Prescribing Kidney Replacement Therapy in Critically Sick Children With Acute Liver Failure

Management of acute liver failure (ALF) and acute on chronic liver failure (ACLF) in the pediatric population can be challenging. Kidney manifestations of liver failure, such as hepatorenal syndrome (HRS) and acute kidney injury (AKI), are increasingly prevalent and may portend a poor prognosis. The overall incidence of AKI in children with ALF has not been well-established, partially due to the difficulty of precisely estimating kidney function in these patients. The true incidence of AKI in pediatric patients may still be underestimated due to decreased creatinine production in patients with advanced liver dysfunction and those with critical conditions including shock and cardiovascular compromise with poor kidney perfusion. Current treatment for kidney dysfunction secondary to liver failure include conservative management, intravenous fluids, and kidney replacement therapy (KRT). Despite the paucity of evidence-based recommendations concerning the application of KRT in children with kidney dysfunction in the setting of ALF, expert clinical opinions have been evaluated regarding the optimal modalities and timing of KRT, dialysis/replacement solutions, blood and dialysate flow rates and dialysis dose, and anticoagulation methods.

Anticoagulation strategies in extracorporeal circulatory devices in adult populations

Extracorporeal circulatory devices such as hemodialysis and extracorporeal membrane oxygenation can be lifesaving; however, they are also prone to pathologic events including device failure, venous and arterial thrombosis, hemorrhage, and an accelerated risk for atherosclerotic disease due to interactions between blood components and device surfaces of varying biocompatibility. While extracorporeal devices may be used acutely for limited periods of time (eg, extracorporeal membrane oxygenation, continuous venovenous hemofiltration, therapeutic apheresis), some patients require chronic use of these technologies (eg, intermittent hemodialysis and left ventricular assist devices). Given the substantial thrombotic risks associated with extracorporeal devices, multiple antiplatelet and anticoagulation strategies-including unfractionated heparin, low-molecular-weight heparin, citrate, direct thrombin inhibitors, and direct oral anticoagulants, have been used to mitigate the thrombotic milieu within the patient and device. In the following manuscript, we outline the current data on anticoagulation strategies for commonly used extracorporeal circulatory devices, highlighting the potential benefits and complications involved with each.

Regional citrate anticoagulation versus no-anticoagulation for continuous venovenous hemofiltration in patients with liver failure and increased bleeding risk: A retrospective case-control study

Objective

There are controversial opinions on anticoagulation for continuous venovenous hemofiltration (CVVH) in patients with liver failure (LF) and increased bleeding risk. Therefore, we conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus no-anticoagulation for CVVH in these patients.

Methods

The included patients were divided into RCA and no-anticoagulation group according to the CVVH anticoagulation strategy they accepted for CVVH. Filter lifespan, bleeding, citrate accumulation, catheter occlusion, and totCa/ionCa ratio were evaluated as outcomes.

Results

In the original cohort, the filter lifespan of the RCA group (41 patients, 79 filters) was significantly longer than the no-anticoagulation group (62 patients, 162 filters) (> 72 hours vs 39.5 hours (IQR 31.2–47.8), P = 0.002). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (HR = 0.459, 95%CI 0.26–0.82, P = 0.008). Four episodes of totCa/ionCa > 2.5 were observed in the RCA group and continuously accepted RCA-CVVH after the reduction of citrate dose and blood flow. No obvious citrate accumulation was observed in these patients. In the matched cohort, the filter lifespan of the RCA group was significantly longer than the no-anticoagulation group (P = 0.013) as well. No significant difference in the episodes of totCa/ionCa > 2.5 was observed between the two matched groups (P = 0.074). Both in the original cohort and the matched cohort, the bleeding, acidosis, alkalosis, and catheter occlusion incidences were not significantly different between the two groups.

Conclusions

In LF patients with increased bleeding risk who underwent CVVH, RCA could prolong the filter lifespan and be safely used with careful blood gas monitoring and citrate dose adjusting. Further prospective, randomized, control studies are warranted to obtain robust evidences.

A pilot study into the use of Continuous Venous Hyperfiltration to manage patients in a critical state with dysregulated inflammation

INTRODUCTION

Haemofiltration paradigms used to manage critically ill patients with a dysregulated inflammatory response (DIR) assess kidney function to monitor its onset, adaptation, and completion. A Continuous Venous Hyperfiltration (CONVEHY) protocol is presented, in which a non-specific adsorption membrane (AN69-ST-Heparin Grafted) is used with citrate as an anticoagulant and substitution fluid. CONVEHY uses tools readily available to achieve kidney related and non-related objectives, and it is guided by the monitoring of pathophysiological responses.

OBJECTIVES

To compare the response to an AN69-ST-HG membrane when heparin (He, n=5: Standard protocol) or citrate (Ci, n=6: CONVEHY protocol) was used to evaluate whether a larger study into the benefits of this protocol would be feasible.

MATERIALS AND METHODS

In a retrospective pilot study, the benefits of the CONVEHY protocol to manage patients with a DIR in a surgical critical care unit (CCUs) were assessed by evaluating the SOFA (Sequential Organ Failure Assessment) (He 11 ± 2.35; Ci 11 ± 3.63: p=0.54) and APACHE II (He 28.60 ± 9.40; Ci 24 ± 8.46: p=0.93) scores.

RESULTS

Nights in hospital (He 35.2 ± 16.3 nights; Ci 9 ± 2.53: p=0.004), hospital admission after discharge from the CCUs (He 40.25 ± 21.82; Ci 13.2 ± 4.09: p=0.063), patients hospitalised >20 days (He 80%; Ci 0%: p=0.048), days requiring mechanical ventilation (He 16 ± 5.66; Ci 4 ± 1.72: p=0.004), and the predicted (55.39 ± 26.13%) versus real mortality in both groups (9.1%: p=0.004).

CONCLUSIONS

The CONVEHY protocol improves the clinical responses of patients with DIR, highlighting the potential value of performing larger and confirmatory studies.