Regional citrate anticoagulation in patients with liver failure--time for a rethink? Crit Care. 2012;16:153. [PMID: 22985662 PMCID: PMC3682254 DOI: 10.1186/cc11492]

APASL clinical practice guidelines on the management of acute kidney injury in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a syndrome that is characterized by the rapid development of organ failures predisposing these patients to a high risk of short-term early death. The main causes of organ failure in these patients are bacterial infections and systemic inflammation, both of which can be severe. For the majority of these patients, a prompt liver transplant is still the only effective course of treatment. Kidneys are one of the most frequent extrahepatic organs that are affected in patients with ACLF, since acute kidney injury (AKI) is reported in 22.8-34% of patients with ACLF. Approach and management of kidney injury could improve overall outcomes in these patients. Importantly, patients with ACLF more frequently have stage 3 AKI with a low rate of response to the current treatment modalities. The objective of the present position paper is to critically review and analyze the published data on AKI in ACLF, evolve a consensus, and provide recommendations for early diagnosis, pathophysiology, prevention, and management of AKI in patients with ACLF. In the absence of direct evidence, we propose expert opinions for guidance in managing AKI in this very challenging group of patients and focus on areas of future research. This consensus will be of major importance to all hepatologists, liver transplant surgeons, and intensivists across the globe.

A single center retrospective study: Comparison between centrifugal separation plasma exchange with ACD-A and membrane separation plasma exchange with heparin on acute liver failure and acute on chronic liver failure

The purpose of this retrospective study is to compare the efficacy and safety of the centrifugal separation therapeutic plasma exchange (TPE) using citrate anticoagulant (cTPEc) with membrane separation TPE using heparin anticoagulant (mTPEh) in liver failure patients. The patients treated by cTPEc were defined as cTPEc group and those treated by mTPEh were defined as mTPEh group, respectively. Clinical characteristics were compared between the two groups. Survival analyses of two groups and subgroups classified by the model for end-stage liver disease (MELD) score were performed by Kaplan-Meier method and were compared by the log-rank test. In this study, there were 51 patients in cTPEc group and 18 patients in mTPEh group, respectively. The overall 28-day survival rate was 76% (39/51) in cTPEc group and 61% (11/18) in mTPEh group (P > .05). The 90-day survival rate was 69% (35/51) in cTPEc group and 50% (9/18) in mTPEh group (P > .05). MELD score = 30 was the best cut-off value to predict the prognosis of patients with liver failure treated with TPE, in mTPEh group as well as cTPEc group. The median of total calcium/ionized calcium ratio (2.84, range from 2.20 to 3.71) after cTPEc was significantly higher than the ratio (1.97, range from 1.73 to 3.19) before cTPEc (P < .001). However, there was no significant difference between the mean concentrations of total calcium before cTPEc and at 48 h after cTPEc. Our study concludes that there was no statistically significant difference in survival rate and complications between cTPEc and mTPEh groups. The liver failure patients tolerated cTPEc treatment via peripheral vascular access with the prognosis similar to mTPEh. The prognosis in patients with MELD score < 30 was better than in patients with MELD score ≥ 30 in both groups. In this study, the patients with acute liver failure (ALF) and acute on chronic liver failure (ACLF) treated with cTPEc tolerated the TPE frequency of every other day without significant clinical adverse event of hypocalcemia with similar outcomes to the mTPEh treatment. For liver failure patients treated with cTPEc, close clinical observation and monitoring ionized calcium are necessary to ensure the patients' safety.

Clinical application of regional citrate anticoagulation for continuous renal replacement therapy in children with liver injury

BACKGROUND

Regional citrate anticoagulation (RCA) is increasingly used for continuous renal replacement therapy (CRRT) in children, but it is rarely used in children with liver injury, especially liver failure (LF). We analyze this issue through the following research.

METHODS

We retrospectively analyzed 75 children with liver injury who underwent RCA-CRRT in the Pediatric Intensive Care Unit (PICU) of Children's Hospital of Chongqing Medical University. The patients were divided into the LF group and liver dysfunction (LD) group. The two groups were compared to evaluate the clinical safety and efficacy of RCA-CRRT in children with liver injury and to explore RCA-CRRT management strategies, in terms of the following indicators: the incidence of bleeding, clotting, citrate accumulation (CA), acid-base imbalance, and electrolyte disturbance, as well as filter lifespans, changes in biochemical indicators, and CRRT parameters adjustment.

RESULTS

The total incidence of CA (TCA) and persistent CA (PCA) in the LF group were significantly higher than those in the LD group (38.6 vs. 16.2%, p < 0.001; 8.4 vs. 1.5%, p < 0.001); and the CA incidence was significantly reduced after adjustment both in the LF (38.6 vs. 8.4%, p < 0.001) and LD groups (16.2 vs. 1.5%, p < 0.001). The incidence of hypocalcemia was significantly higher in the LF group than in the LD group either before (34.9 vs. 8.8%, p < 0.001) or after treatment (12.0 vs. 0%, p < 0.001). The speed of the blood and citrate pumps after adjustment was lower than the initial setting values in both the LF and LD groups. The dialysis speed plus replacement speed were higher than the initial settings parameters.

CONCLUSION

For children undergoing RCA-CRRT, the risks of CA and hypocalcemia are significantly higher in children with liver failure than those with liver dysfunction, but through the proper adjustment of the protocol, RCA-CRRT can still be safely and effectively approached for children with LD and even LF.

Measurement of the Concentration of Citrate in Human Biofluids in Patients Undergoing Continuous Renal Replacement Therapy Using Regional Citrate Anticoagulation: Application of a Two-Step Enzymatic Assay

BACKGROUND

Continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) is now commonly used to treat acute kidney injury in critically ill patients. The concentration of citrate is not routinely measured, with citrate accumulation and/or toxicity primarily assessed using surrogate measures.

OBJECTIVES

The aim of this study was to measure the concentration of citrate in plasma and ultrafiltrate in patients receiving CRRT with RCA using a modified commercial enzymatic assay.

METHODS

After meeting inclusion criteria, blood was sampled from 20 patients before, during, and after episodes of filtration. Using spectrophotometry, samples were tested for citrate concentration. Demographic and other clinical and biochemical data were also collected. Throughout, a 15 mmol/L solution of trisodium citrate was used as the prefilter anticoagulant. Results were analysed using STATA (v15.0) and presented as mean (SD), median (IQR), or simple proportion. Comparisons were made using either the Student t test or the Wilcoxon rank-sum test. Correlation was assessed using Pearson's r.

RESULTS

Twenty patients (17 males) were enrolled in the study. Mean (SD) age was 63.7 years (9.9). Median (IQR) ICU length of stay was 281 h (199, 422) with 85% undergoing intermittent positive pressure ventilation. Median APACHE 3 score was 95 (87, 117) with an overall 30% mortality rate. Median filtration time was 85 h (46, 149). No difference was found between pre- and post-filtration plasma citrate concentrations (79 µmol/L [50] vs. 71 µmol/L [42], p = 0.65). Mean citrate concentration during filtration was 508 µmol/L (221) with a maximum of 1,070 µmol/L. This was significantly higher than the pre/post levels (p < 0.001).

CONCLUSIONS

Plasma concentrations of citrate rose significantly during episodes of CRRT using RCA returning back to normal after cessation of treatment.

Indian National Association for the Study of Liver Consensus Statement on Acute Liver Failure (Part-2): Management of Acute Liver Failure

Acute liver failure (ALF) is not an uncommon complication of a common disease such as acute hepatitis. Viral hepatitis followed by antituberculosis drug-induced hepatotoxicity are the commonest causes of ALF in India. Clinically, such patients present with appearance of jaundice, encephalopathy, and coagulopathy. Hepatic encephalopathy (HE) and cerebral edema are central and most important clinical event in the course of ALF, followed by superadded infections, and determine the outcome in these patients. The pathogenesis of encephalopathy and cerebral edema in ALF is unique and multifactorial. Ammonia plays a crucial role in the pathogenesis, and several therapies aim to correct this abnormality. The role of newer ammonia-lowering agents is still evolving. These patients are best managed at a tertiary care hospital with facility for liver transplantation (LT). Aggressive intensive medical management has been documented to salvage a substantial proportion of patients. In those with poor prognostic factors, LT is the only effective therapy that has been shown to improve survival. However, recognizing suitable patients with poor prognosis has remained a challenge. Close monitoring, early identification and treatment of complications, and couseling for transplant form the first-line approach to manage such patients. Recent research shows that use of dynamic prognostic models is better for selecting patients undergoing liver transplantation and timely transplant can save life of patients with ALF with poor prognostic factors.

Membrane-based therapeutic plasma exchange in dogs: Prescription, anticoagulation, and metabolic response

BACKGROUND

Therapeutic plasma exchange (TPE) is used increasingly in small animals to remove circulating large molecular products such as antibodies, pathogenic proteins, and protein-bound toxins. Specific, efficient, and safe protocols need to be developed.

HYPOTHESIS/OBJECTIVES

To describe the technique of membrane-based TPE, the resulting physiological and metabolic changes, and to define an adequate regional citrate anticoagulation protocol.

ANIMALS

Thirty-four dogs treated with TPE (2011-2017).

METHODS

Retrospective review of all TPE treatments performed at the Vetsuisse Faculty, University of Bern, identified through a search of the institutional database for extracorporeal treatments.

RESULTS

Sixty-four treatments were performed, resulting in 1.0 plasma volume exchange (range, 0.4-1.1). Replacement fluids included fresh frozen plasma (12%-100% volume), colloids (0%-52%), human albumin (0%-41%), and saline (0%-70%). Anticoagulation was performed with regional citrate (n = 24), systemic heparinization (n = 2), or combined (n = 38). Main relevant laboratory changes included a 24.7% decrease in total proteins (interquartile range, 16.7-31.4; P < .001), 53% in fibrinogen (-30 to 63; P = .009), 36% in bilirubin (13-43, P = .02), 9.0% in urea (0.7-15.7; P < .001), and 4.5% in creatinine (-6.6 to 10.6; P = .006). Citrate accumulation was evidenced in all dogs, more pronounced in those with renal but not with hepatic impairment. Maximal tolerable citrate rates were estimated as 5.5 and 9.0 μmol/kg/min for treatments in dogs with and without renal impairment, respectively. Complications were observed in 22 treatments (34%) and were fatal in 2 dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Therapeutic plasma exchange causes metabolic and biochemical alterations. Understanding these effects makes possible to anticipate most complications and to improve safety of the procedure.

Algorithms for managing coagulation disorders in liver disease

Patients with advanced liver disease have traditionally been considered at risk for bleeding complications. However, although bleeding in patients with cirrhosis frequently occurs due to complications of portal hypertension, research performed within the last 15 years has increasingly shown that hemostasis in patients with liver failure generally achieves a state of "rebalance", whereby compensatory systems restore a relatively neutral or even slightly pro-thrombotic state. Much recent clinical and in vitro research has, in fact, shown over-compensation, such that patients with acute and stable chronic liver failure may have a thrombotic tendency, which may participate in the progression of liver disease and cause systemic and portal thrombosis. Investigators have started to identify differences in hemostasis in patients with unstable cirrhosis, the newly defined syndrome of acute-on-chronic liver failure (ACLF), compared to those with stable cirrhosis. The following discussion will summarize much of the background of rebalanced hemostasis in patients with cirrhosis and acute liver failure (ALF), and suggest management algorithms for coagulation abnormalities before invasive procedures, during active bleeding, and for prophylaxis and treatment of thrombotic complications.

Good Tolerance of Citrate Accumulation due to Plasma Exchange among Patients with Acute-on-Chronic Liver Failure: A Prospective, Observational Study

Aim

To assess the tolerance of citrate accumulation due to plasma exchange (PE) among patients with acute-on-chronic liver failure (ACLF).

Methods

A prospective, observational study was conducted among patients with ACLF who received heparin anticoagulation during PE-centered therapy without filtration and dialysis. Citrate accumulation was defined as the value of total calcium (Catot) to ionized calcium (Caion) ratio (Catot/Caion) greater than or equal to 2.5 (Catot/Caion ≥ 2.5).

Results

Fifty-four patients were enrolled. The mean age and MELD score were 50.0 ± 11.3 years old and 25 ± 7, respectively. Thirty-three patients had liver cirrhosis. The total 3-month survival rate was 57.4% (31/54). The mean Catot/Caion at the time before PE was 2.05 ± 0.14. Catot/Caion ≥ 2.5 occurred in 100.0% (54/54) and 29.6% (16/54) of patients with mean Catot/Caion of 4.34 ± 1.52 and 2.36 ± 0.32 immediately after PE and 1 hour after PE, respectively, and these levels were much higher than those before PE (p < 0.01). However, all values returned to lower than 2.5 by the next morning with no difference from those before PE (2.10 ± 0.14 versus 2.05 ± 0.14, p > 0.05). Hypocalcemia (ionized calcium) and mild alkalosis were the main metabolic alterations. No symptoms associated with hypocalcemia occurred.

Conclusions

Citrate accumulation is well tolerated by patients with ACLF who receive PE-centered therapy without filtration and dialysis. This study is regeristed with ChiCTR-OOC-17013618.

Application of regional citrate anticoagulation during plasma adsorption and plasma exchange for patients with liver failure at high risk of bleeding

AIM

To analyze the feasibility and safety of regional citrate anticoagulation (RCA) during plasma adsorption (PA) plus plasma exchange (PE) therapy for patients with liver failure at high risk of bleeding.

METHODS

This was a retrospective study conducted at the Center of Infectious Diseases, West China Hospital of Sichuan University from October 2016 to July 2017. The clinical data of patients with liver failure at high risk of bleeding who received RCA during PA plus PE therapy were collected. The therapeutic effects, citrate accumulation, electrolytes, and acid-base changes were retrospectively analyzed. Citrate accumulation was defined as the total calcium (Ca_tot) to ionized calcium (Ca_ion) ratio (Ca_tot/Ca_ion) ≥ 2.5.

RESULTS

Of the seven patients included, two survived and five died. Twenty four sessions of RCA for PA plus PE therapy were accomplished. The mean Ca_ionin vitro during PA therapy was 0.28 mmol/L ± 0.09 mmol/L. Citrate accumulation occurred in 45.8% (11/24) of sessions during PA therapy and in all the sessions at the end of PE therapy. Although citrate accumulation still occurred in 41.7% (10/24) of sessions 2 h after PE therapy, it had been decreased obviously when compared with that at the end of PE therapy (P < 0.01) and it was not present by the next morning. No new bleeding occurred and the original bleeding did not deteriorate during and after PA plus PE therapy. The main side effects were alkalosis and transient low level of Ca_ion and high level of Ca_tot.

CONCLUSION

Patients with liver failure still have certain ability to metabolize citrate and tolerate citrate accumulation. RCA may be feasible and safe in the PA plus PE therapy for patients with liver failure.

Safety and Efficacy of Citrate Anticoagulation for Continuous Renal Replacement Therapy for Acute Kidney Injury After Liver Transplantation: A Single-Center Experience

BACKGROUND

Acute kidney injury (AKI) after liver transplantation (LT) is a frequent and serious complication. The incidence of AKI requiring continuous renal replacement therapy (CRRT) ranges from 10% to 30%. Kidney Disease: Improving Global Outcomes guidelines indicate the use of citrate as a locoregional anticoagulant drug for CRRT regardless of the patient's hemorrhagic risk. Despite this indication, however, the use of citrate is still under debate in patients with liver failure and/or LT owing to the potential risk of plasmatic citrate accumulation due to reduced liver clearance. The aim of this study was to evaluate the safety and efficacy of citrate as a locoregional anticoagulation drug in CRRT for AKI after LT.

METHODS

A retrospective analysis was performed in patients with AKI after liver transplantation who were treated with CRRT using citrate as local anticoagulant. Five patients were enrolled from January to December 2015.

RESULTS

No patients showed complications related to citrate (metabolic acidosis, hyperlactatemia, hypercalcemia, or hypernatremia). All treatments with heparin were stopped owing to circuit clotting. Treatments with citrate was interrupted where it was no longer needed or when other examinations had to be made. None were stopped because of circuit coagulation.

CONCLUSIONS

At our center, 5 patients have been successfully treated with the use of CRRT with citrate for AKI during the post-LT course. Our results, though on a small series of patients, provide evidence that CRRT with citrate can be a safe and promising treatment for AKI after LT.

Prothrombotic State in a Patient With Acute Liver Failure: The Question of Anticoagulation

A 35-year-old male with acute liver failure due to acute hepatitis B virus infection was admitted to the intensive care unit with significant hepatocellular injury, cholestasis, abnormal standard coagulation tests, normal rotational thromboelastometry indices, and without signs of bleeding. He underwent emergency liver transplantation without requiring blood product transfusions or procoagulant treatments. The postoperative course was complicated by deep vein thrombosis and impending hepatic artery thrombosis treated with unfractionated heparin, aspirin, and intravenous prostacyclin. The patient survived and made a full neurological recovery. This case revealed the presence of a prothrombotic state due to a rebalanced coagulation system in a patient with liver dysfunction that was not identifiable by standard coagulation tests. This case emphasizes that identifying and treating coagulopathy is very difficult in liver failure patients and requires specific diagnostic and therapeutic strategies.

EASL Clinical Practical Guidelines on the management of acute (fulminant) liver failure

The term acute liver failure (ALF) is frequently applied as a generic expression to describe patients presenting with or developing an acute episode of liver dysfunction. In the context of hepatological practice, however, ALF refers to a highly specific and rare syndrome, characterised by an acute abnormality of liver blood tests in an individual without underlying chronic liver disease. The disease process is associated with development of a coagulopathy of liver aetiology, and clinically apparent altered level of consciousness due to hepatic encephalopathy. Several important measures are immediately necessary when the patient presents for medical attention. These, as well as additional clinical procedures will be the subject of these clinical practice guidelines.

Dialysis-dependent acute kidney injury in children with end-stage liver disease: prevalence, dialysis modalities and outcome

BACKGROUND

Acute kidney injury (AKI) is a major complication in children with hepatic failure which leads to increased morbidity and mortality. The aim of this study was to provide paediatric data on the prevalence of dialysis-dependent AKI (dAKI), the feasibility and efficacy of dialysis methods and outcome.

METHODS

We conducted a retrospective analysis of 367 children listed for orthotopic liver transplantation (OLT) in our centre during the past decade.

RESULTS

Data on 30 children (15 boys, 15 girls) were compiled for retrospective analysis, and data on dialysis feasibility and efficacy were available for 26 of these. Median age was 3.5 (range 0.4-17.7) years. Median MELD (Model For End-Stage Liver Disease) score was 33. dAKI was caused by hepato-renal syndrome in 16 of the 30 children. Twenty-one patients were treated with continuous veno-venous haemofiltration (CVVH), and nine patients received peritoneal dialysis (PD). Overall mortality was 77%. Mortality within the PD-group was 100 % versus 67% in the CVVH-group (p = 0.039). Urea reduction rate within the first 24 h of treatment was 12.9% in the PD group and 23.5% in the CVVH group (p = 0.019).

CONCLUSIONS

Children with end-stage liver disease have a high risk for dAKI associated with high mortality. CVVH is associated with better efficacy and less mortality than PD.

Hepatorenal syndrome: Update on diagnosis and treatment

Acute kidney injury (AKI) is a common complication in patients with end-stage liver disease and advanced cirrhosis regardless of the underlying cause. Hepatorenal syndrome (HRS), a functional form of kidney failure, is one of the many possible causes of AKI. HRS is potentially reversible but involves highly complex pathogenetic mechanisms and equally complex clinical and therapeutic management. Once HRS has developed, it has a very poor prognosis. This review focuses on the diagnostic approach to HRS and discusses the therapeutic protocols currently adopted in clinical practice.

Citrate anticoagulation for continuous renal replacement therapy in small children

BACKGROUND

Regional citrate anticoagulation (RCA) is one of the methods used to prevent clotting in continuous renal replacement therapy (CRRT). The aim of this study was to describe the outcomes and complications of RCA-CRRT in comparison to heparin anticoagulation (HA)-CRRT in critically ill children.

METHODS

This study was a retrospective review of 30 critically ill children (16 on RCA- and 14 on HA-CRRT) who underwent at least 24 h of CRRT. The mean body weight of the children was 8.69 ± 5.63 kg. RCA-CRRT was performed with a commercially available pre-dilution citrate solution (Prismocitrate 18/0).

RESULTS

The mean time on RCA-CRRT and HA-CRRT was 148.73 ± 131.58 and 110.24 ± 105.38 h, respectively. Circuit lifetime was significantly higher in RCA-CRRT than in HA-CRRT (58.04 ± 51.18 h vs. 37.64 ± 32.51 h, respectively; p = 0.030). Circuit clotting was observed in 11.63 % of children receiving RCA-CRRT and 34.15 % of those receiving HA-CRRT. Episodic electrolyte and metabolic disturbances were more common in children receiving RCA-CRRT. The survival at discharge from the hospital was 37.5 and 14.3 % among children receiving RCA-CRRT and HA-CRRT, respectively.

CONCLUSIONS

In critically ill children with a low body weight, RCA appeared to be safe and easy to used. Among our patient cohort, RCA was more effective in preventing circuit clotting and provided a better circuit lifetime than HA.

Beyond the randomized clinical trial: citrate for continuous renal replacement therapy in clinical practice

BACKGROUND

Premature circuit clotting is a major problem during continuous renal replacement therapy (CRRT). Six randomized controlled trials confirmed that regional anticoagulation with citrate is superior to heparin. Our objective was to compare circuit patency with citrate, heparin and epoprostenol in routine clinical practice.

METHODS

We retrospectively analysed data on circuit patency of all circuits used in a single centre between September 2008 and August 2009. We differentiated between premature filter clotting, elective discontinuation and waste.

RESULTS

309 patients were treated with CRRT (n = 2,059 circuits). The mean age was 65.7; 63.8% were male. The methods to maintain circuit patency were unfractionated heparin (42.3%), epoprostenol (23.0%), citrate (14.7%), combinations of different anticoagulants (14.6%) and no anticoagulation (4.7%). Premature clotting was the most common reason for circuit discontinuation among circuits anticoagulated with heparin, epoprostenol or combinations of different anticoagulants (59-62%). Among circuits anticoagulated with citrate the main reason for discontinuation was elective (61%). Hazard regression analysis confirmed significantly better circuit survival with citrate. Changing from heparin to citrate decreased the risk of premature circuit clotting by 75.8%.

CONCLUSION

In routine clinical practice, regional anticoagulation with citrate is associated with significantly better circuit patency than heparin or epoprostenol.