Effectiveness of combining plasma exchange and continuous hemodiafiltration in patients with postoperative liver failure

Regional citrate anticoagulation for replacement therapy in patients with liver failure: A systematic review and meta-analysis

Background

Citrate refers to an anticoagulant agent commonly used in extracorporeal organ support. Its application is limited in patients with liver failure (LF) due to the increased risk of citrate accumulation induced by liver metabolic dysfunction. This systematic review aims to assess the efficacy and safety of regional citrate anticoagulation in extracorporeal circulation for patients with liver failure.

Methods

PubMed, Web of Science, Embase, and Cochrane Library were searched. Studies regarding extracorporeal organ support therapy for LF were included to assess the efficacy and safety of regional citrate anticoagulation. Methodological quality of included studies were assessed using the Methodological Index for Non-randomized Studies (MINORS). Meta-analysis was performed using R software (version 4.2.0).

Results

There were 19 eligible studies included, involving 1026 participants. Random-effect model showed an in-hospital mortality of 42.2% [95%CI (27.2, 57.9)] in LF patients receiving extracorporeal organ support. The during-treatment incidence of filter coagulation, citrate accumulation, and bleeding were 4.4% [95%CI (1.6-8.3)], 6.7% [95%CI (1.5-14.4)], and 5.0% [95%CI (1.9-9.3)], respectively. The total bilirubin(TBIL), alanine transaminase (ALT), aspartate transaminase(AST), serum creatinine(SCr), blood urea nitrogen(BUN), and lactate(LA) decreased, compared with those before the treatment, and the total calcium/ionized calcium ratio, platelet(PLT), activated partial thromboplastin time(APTT), serum potential of hydrogen(pH), buffer base(BB), and base excess(BE) increased.

Conclusion

Regional citrate anticoagulation might be effective and safe in LF extracorporeal organ support. Closely monitoring and timely adjusting during the process could reduce the risk for complications. More prospective clinical trials of considerable quality are needed to further support our findings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022337767.

Role of liver support systems in the management of post hepatectomy liver failure: A systematic review of the literature

Backgrounds/Aims

Post-hepatectomy liver failure (PHLF) is a serious complication following liver resection, with limited treatment options, and is associated with high mortality. There is a need to evaluate the role of systems that support the function of the liver after PHLF.

Aims

The aim of this study was to review the literature and summarize the role of liver support systems (LSS) in the management of PHLF. Publications of interest were identified using systematically designed searches. Following screening, data from the relevant publications was extracted, and pooled where possible.

Findings

Systematic review identified nine studies, which used either Plasma Exchange (PE) or Molecular Adsorbent Recirculating System (MARS) as LSS after PHLF. Across all studies, the pooled 90-day mortality rate was 38% (95% CI: 9-70%). However, there was substantial heterogeneity, likely since studies used a variety of definitions for PHLF, and had different selection criteria for patient eligibility for LSS treatment.

Conclusions

The current evidence is insufficient to recommend LSS for the routine management of severe PHLF, with the current literature consisting of only a limited number of studies. There is a definite need for larger, multicenter, prospective studies, evaluating the conventional and newer modalities of support systems, with a view to improve the outcomes in this group of patients.

Artificial liver support systems

Artificial liver systems are used to bridge between transplantation or to allow a patient's liver to recover. They are used in patients with acute liver failure (ALF) and acute-on-chronic liver failure. There are five artificial systems currently in use: molecular adsorbent recirculating system (MARS), single-pass albumin dialysis (SPAD), Prometheus, selective plasma filtration therapy, and hemodiafiltration. The aim is to compare existing data on the efficiency of these devices. A literature search was conducted using online libraries. Inclusion criteria included randomized control trials or comparative human studies published after the year 2000. A systematic review was conducted for the five individual devices with a more detailed comparison of the biochemistry for the SPAD and MARS systems. Eighty-nine patients were involved in the review comparing SPAD and MARS. Results showed that there was an average reduction in bilirubin (-53 μmol/L in MARS and -50 μmol/L in SPAD), creatinine (-19.5 μmol/L in MARS and -7.5 μmol/L in SPAD), urea (-0.9 mmol/L in MARS and -0.75 mmol/L in SPAD), and gamma-glutamyl transferase (-0.215 μmol/L·s in MARS and -0.295 μmol/L·s in SPAD) in both SPAD and MARS. However, there was no significant difference between the changes in the two systems. This review demonstrated that both MARS and SPAD aid recovery of ALF. There is no difference between the efficiency of MARS and SPAD. Because of the limited data, there is a need for more randomized control trials. Evaluating cost and patient preference would aid in differentiating the systems.

Description of parallel and sequential configurations for concurrent therapeutic plasma exchange and continuous kidney replacement therapy in adults

Therapeutic plasma exchange (TPE) and continuous kidney replacement therapy (CKRT) are extracorporeal therapeutic procedures often implemented in management of patients. Critically ill patients may be afflicted with disease processes that require both TPE and CKRT. Performing TPE discontinuous with CKRT is technically easier, however, it disrupts CKRT and may compromise with CKRT efficiency or hemofilter life. Concurrent TPE with CKRT offers several advantages including simultaneous control of disease process and correction of electrolyte, fluid, and acid-base disturbances that may accompany TPE. Additionally, TPE may be performed by either centrifugation method or membrane plasma separation method. The technical specifications of these methods may influence the methodology of concurrent connections. This report describes and reviews two different approaches to circuit arrangements when establishing concurrent TPE and CKRT.

RRT Selection for AKI Patients With Critical Illness

Acute kidney injury (AKI) is a critical burden on intensive care units in Asia. Renal replacement therapy (RRT) acts as strong supportive care for severe AKI. However, various RRT modalities are used in Asia because of the diversity in ethics, climate, geographic features, and socioeconomic status. Extracorporeal blood purification is used commonly in Asian intensive care units; however, intermittent RRT is preferred in developing countries because of cost and infrastructure issues. Conversely, continuous RRT is preferred in developed countries, indicating the predominance of hospital-acquired AKI patients with complications of hemodynamic instability. Peritoneal dialysis is delivered less frequently, although several studies have suggested promising results for peritoneal dialysis in AKI treatment. Of note, not all RRT modalities are available as a standard procedure in some Asian regions, and it is absolutely necessary to develop a sustainable infrastructure that can deliver optimal care for all AKI patients.

Protective effects of oxymatrine against lipopolysaccharide/D‑galactosamine‑induced acute liver failure through oxidative damage, via activation of Nrf2/HO‑1 and modulation of inflammatory TLR4‑signaling pathways

Oxymatrine has a variety of pharmacological functions, including anti-viral, anti-liver fibrotic, anti-cancer, anti‑bacterial, anti‑epidemic, analgesic, anti‑allergy and anti‑inflammatory properties. The present study aimed to investigate the protective effects of oxymatrine against lipopolysaccharide (LPS)/D‑galactosamine (D‑GalN)‑induced acute liver failure and the associated underlying mechanisms. Mice were administrated 4 mg/kg LPS and 600 mg/kg D‑GalN. Then, mice in the Oxymatrine group were treated with 120 mg/kg of oxymatrine for 4 weeks. Oxymatrine treatment increased survival rate, decreased plasma aspartate transaminase and alanine aminotransferase activity, increased superoxide dismutase and glutathione peroxidase and decreased malondialdehyde, tumor necrosis factor‑ and myeloperoxidase activities in mice with LPS/D‑GalN‑induced liver failure. Furthermore, Oxymatrine activated nuclear factor erythroid 2‑related factor (Nrf) 2 and heme oxygenase (HO)‑1 protein expression, and suppressed Toll like receptor (TLR)4, myeloid differentiation primary response 88 and nuclear factor‑κB protein expression in mice LPS/D‑GalN mice. Overall, the present study suggests that oxymatrine effectively attenuates LPS/D‑GalN‑induced acute liver failure by oxidative damage via activation of Nrf2/HO‑1 and modulation of TLR4‑dependent inflammatory signaling pathways.

Plasma exchange-centered artificial liver support system in hepatitis B virus-related acute-on-chronic liver failure: a nationwide prospective multicenter study in China

BACKGROUND

Plasma exchange (PE)-centered artificial liver support system reduced the high mortality rate of hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF). But the data were diverse in different medical centers. The present prospective nationwide study was to evaluate the effects of PE on patients with HBV-ACLF at different stages.

METHODS

From December 2009 to December 2011, we evaluated 250 patients at different stages of HBV-ACLF from 10 major medical centers in China. All the laboratory parameters were collected at admission, before and after PE.

RESULTS

Among the 250 patients who underwent 661 rounds of PE, one-month survival rate was 61.6%; 141 (56.4%) showed improvement after PE. Variables such as age (P=0.000), levels of total bilirubin (TB, P=0.000), direct bilirubin (P=0.000), total triglycerides (P=0.000), low-density lipoprotein (P=0.022), Na+ (P=0.014), Cl- (P=0.038), creatinine (Cr, P=0.007), fibrinogen (P=0.000), prothrombin time (PT, P=0.000), white blood cell (P=0.000), platelet (P=0.003) and MELD (P=0.000) were significantly related to prognosis. Multivariate logistic regression analysis showed that age, disease stage, TB, Cr and PT levels were independent risk factors of mortality among HBV-ACLF patients.

CONCLUSIONS

PE can improve the clinical outcome of patients with HBV-ACLF. Levels of TB, Cr and PT, age and disease stage help to predict prognosis.

Effect of plasma exchange plus hemofiltration on inflammatory cytokines in patients with liver failure

AIM: To analyze the influence of plasma exchange (PE) combined with hemofiltration (HF) on the levels of serum inflammatory cytokines and biochemical parameters in patients with liver failure.

METHODS: Seventeen patients were treated by PE plus HF and 20 patients were treated by PE alone. Serum levels of cytokines including tumor necrosis factor (TNF), interleukin (IL)-2 receptor, IL-6, IL-10 and biochemical parameters were measured before and after treatment. The differences in the levels of serum cytokines and biochemical parameters were compared between the two groups.

RESULTS: There were significant differences in biochemical parameters except albumin level between before and after treatment in the PE plus HF group (P < 0.05 for all). Total bilirubin (T-BIL), blood urea nitrogen (BUN), creatinine (CRE), ammonia (NH₃) and C reactive protein (CRP) after treatment differed significantly between the two groups (P < 0.05 for all). The levels of tumor necrosis factor (TNF), IL-2R, IL-6 and IL-10 after treatment were significantly lower than those before treatment in the PE plus HF group (P < 0.05 all), and these parameters in the combination group after treatment were significantly lower than those in the PE group (all P < 0.05). Total effective rate was 82.4% in the PE plus HF group, significantly higher than that in the PE group (P < 0.05).

CONCLUSION: The results suggest that serum levels of inflammatory cytokines can be significantly reduced by PE plus HF therapy, and the curative effect of PE plus HF is more remarkable than PE alone in patients with liver failure.

Effects of plasma exchange combined with continuous renal replacement therapy on acute fatty liver of pregnancy

BACKGROUND

Acute fatty liver of pregnancy (AFLP) in the third trimester or early postpartum period can lead to fatal liver damage. Its traditional therapy is not very effective in facilitating hepatic recovery. The safety and effect of plasma exchange (PE) in combination with continuous renal replacement therapy (CRRT) (PE+CRRT) for AFLP still needs evaluation.

METHODS

Five AFLP patients with hepatic encephalopathy and renal failure were subjected to PE+CRRT in our department from 2007 to 2012. Their symptoms, physical signs and results were observed, and all relevant laboratory tests were compared before and after PE+CRRT.

RESULTS

All the 5 patients were well tolerated to the therapy. Four of them responded to the treatment and showed improvement in clinical symptoms/signs and laboratory results, and they were cured and discharged home after the treatment. One patient succeeded in bridging to transplantation for slowing down hepatic failure and its complications process after 2 treatment sessions. Intensive care unit stay and hospital stay were 9.4 (range 5-18) and 25.0 days (range 11-42), respectively.

CONCLUSION

PE+CRRT is safe and effective and should be used immediately at the onset of hepatic encephalopathy and/or renal failure in patients with AFLP.

Techniques of extracorporeal cytokine removal: a systematic review of human studies

BACKGROUND AND AIMS

Hypercytokinemia is believed to be harmful and reducing cytokine levels is considered beneficial. Extracorporeal blood purification (EBP) techniques have been studied for the purpose of cytokine reduction. We aimed to study the efficacy of various EBP techniques for cytokine removal as defined by technical measures.

METHOD

We conducted a systematic search for human clinical trials which focused on technical measures of cytokine removal by EBP techniques. We identified 41 articles and analyzed cytokine removal according to clearance (CL), sieving coefficient (SC), ultrafiltrate (UF) concentration and percentage removed.

RESULTS

We identified the following techniques for cytokine removal: standard hemofiltration, high volume hemofiltration (HVHF), high cut-off (HCO) hemofiltration, plasma filtration techniques, and adsorption techniques, ultrafiltration (UF) techniques relating to cardiopulmonary bypass (CPB), extracorporeal liver support systems and hybrid techniques including combined plasma filtration adsorption. Standard filtration techniques and UF techniques during CPB were generally poor at removing cytokines (median CL for interleukin 6 [IL-6]: 1.09 mL/min, TNF-alpha 0.74 mL/min). High cut-off techniques consistently offered moderate cytokine removal (median CL for IL-6: 26.5 mL/min, interleukin 1 receptor antagonist [IL-1RA]: 40.2 mL/min). Plasma filtration and extracorporeal liver support appear promising but data are few. Only one paper studied combined plasma filtration and adsorption and found low rates of removal. The clinical significance of the cytokine removal achieved with more efficacious techniques is unknown.

CONCLUSION

Human clinical trials indicate that high cut-off hemofiltration techniques, and perhaps plasma filtration and extracorporeal liver support techniques are likely more efficient in removing cytokines than standard techniques.

Multicenter study of plasma diafiltration in patients with acute liver failure

Plasma diafiltration (PDF) is a blood purification therapy in which simple plasma exchange (PE) is performed using a selective membrane plasma separator while the dialysate flows outside the hollow fibers. A prospective, multicenter study was undertaken to evaluate the changes in bilirubin, IL-18, and cystatin C, as well as the 28-day and 90-day survival rates, with the use of PDF according to the level of severity as measured by the Model for End-Stage Liver Disease (MELD) score. Twenty-one patients with liver failure were studied: 10 patients had fulminant hepatitis and PDF therapies were performed 28 times; 11 had acute liver failure with the therapy performed 96 times. Levels of total bilirubin, IL-18, and cystatin C decreased significantly after treatment. The 28-day survival rate was 70.0% and that at 90 days was 16.7%. According to the severity of the MELD score, each of the results compared well with the use of Molecular Adsorbent Recirculating System or Prometheus therapy. In conclusion, PDF appears to be one of the most useful blood purification therapies for use in cases of acute liver failure in terms of medical economics and the removal of water-soluble and albumin-bound toxins.

Pro-inflammatory interleukin-18 and Caspase-1 serum levels in liver failure are unaffected by MARS treatment

BACKGROUND

The pro-inflammatory cytokine IL-18 and its activator Caspase-1 are involved in acute liver failure and acute-on-chronic-liver-failure. In acute liver failure and acute-on-chronic-liver-failure, the MARS system has been used to support liver function. Enhancement of IL-18, as seen in other extracorporeal-support systems like hemodialysis might thus have mitigated beneficial effects of the MARS system in acute hepatic failure.

PATIENTS AND METHODS

We measured serum concentrations of IL-18 and Caspase-1 in 10 patients with acute liver failure and 10 patients suffering from acute-on-chronic-liver-failure, who were all treated with MARS. Thirteen patients suffering from chronic hepatic failure and 15 healthy individuals served as controls. Data are given as mean with 95% CI.

RESULTS

Baseline IL-18 serum concentrations were significantly increased in acute liver failure and acute-on-chronic-liver-failure patients as compared to chronic hepatic failure (P=0.0039 and P=0.0011, respectively) and controls (P=0.0028 and P=0.0014, respectively). Caspase-1 serum concentrations were as well significantly elevated in the acute liver failure and acute-on-chronic-liver-failure groups as compared to chronic hepatic failure patients (P=0.0039 and P=0.0232, respectively) and controls P<0.0001 and P<0.0007, respectively). IL-18 and Caspase-1 did not change significantly during MARS treatment in acute liver failure and acute-on-chronic-liver-failure patients.

CONCLUSIONS

MARS had no effect on IL-18 and Caspase-1 serum concentrations in acute liver failure and acute-on-chronic-liver-failure, providing no evidence of harmful effects by the increase of these potentially hepatocidal cytokines.

Etiology and outcome of acute liver failure: retrospective analysis of 50 patients treated at a single center

BACKGROUND AND AIM

Acute liver failure (ALF) remains a devastating disease carrying considerable mortality. Since deceased donor liver transplantation is rarely performed in Japan, the artificial liver support system (ALS) and living donor liver transplantation (LDLT) are the main modalities used for treatment of ALF. The aim of this study was to analyze the outcome of ALF patients and to evaluate therapies for ALF according to etiology.

METHODS

Fifty consecutive patients with ALF were treated between January 1990 and December 2006. Prior to 1997, patients received ALS only. After 1997, ALS and/or LDLT were applied. LDLT was performed in 10 patients.

RESULTS

Four of 15 (27%) pre-1997 ALF patients survived, and 16 of 35 (46%) post-1997 ALF patients survived, including eight who underwent LDLT. The causes of ALF were acute hepatitis B virus (HBV) infection in 18%, severe acute exacerbation (SAE) of chronic HBV infection in 18%, autoimmune hepatitis (AIH) in 8%, and cryptogenic hepatitis in 44%. In total, 67% of the patients with ALF caused by acute HBV infection and AIH were cured without LDLT; only 11% of patients with ALF caused by SAE of HBV and 24% of cryptogenic hepatitis were successfully treated without LDLT. Notably, 80% of patients with cryptogenic hepatitis who underwent LDLT survived.

CONCLUSION

Since 1997, the survival rate of ALF patients has increased, mainly due to the introduction of LDLT. Liver transplantation should be performed especially in patients with ALF caused by SAE of HBV and cryptogenic hepatitis.

A Case Report of Hepatorenal Syndrome Treated With Plasma Diafiltration (Selective Plasma Filtration with Dialysis)

Plasma diafiltration (PDF) (selective plasma filtration with dialysis) is blood purification therapy in which simple plasma exchange is performed using a membrane plasma separator (Evacure EC-2A) while dialysate flows outside of the hollow-fibers. A 74-year old man with hepatorenal syndrome underwent four sessions of PDF and three sessions of HDF. Finally he recovered from hepatorenal syndrome. In this therapy, the levels of total bilirubin, interleukin-18, creatinine, and cystatin C were significantly reduced. On the other hand, there were no significant differences in the total protein and albumin levels before and after PDF. PDF may be one of the most useful blood purification therapies for hepatorenal syndrome in terms of medical economics.

Antioxidant properties of Krebs cycle intermediates against malonate pro-oxidant activity in vitro: A comparative study using the colorimetric method and HPLC analysis to determine malondialdehyde in rat brain homogenates

A variety of Krebs cycle intermediaries has been shown to possess antioxidant properties in different in vivo and in vitro systems. Here we examined whether citrate, succinate, malate, oxaloacetate, fumarate and alpha-ketoglutarate could modulate malonate-induced thiobarbituric acid-reactive species (TBARS) production in rat brain homogenate. The mechanisms involved in their antioxidant activity were also determined using two analytical methods: 1) a popular spectrophotometric method (Ohkawa, H., Ohishi, N., Yagi, K., 1979. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Analytical Biochemistry 95, 351-358.) and a high performance liquid chromatographic (HPLC) procedure (Grotto, D., Santa Maria, L. D., Boeira, S., Valentini, J., Charão, M. F., Moro, A. M., Nascimento, P. C., Pomblum, V. J., Garcia, S. C., 2006. Rapid quantification of malondialdehyde in plasma by high performance liquid chromatography-visible detection. Journal of Pharmaceutical and Biomedical Analysis 43, 619-624.). Citrate, malate, and oxaloacetate reduced both basal and malonate-induced TBARS production. Their effects were not changed by pre-treatment of rat brain homogenates at 100 degrees C for 10 min. alpha-Ketoglutarate increased basal TBARS without changing malonate-induced TBARS production in fresh and heat-treated homogenates. Succinate reduced basal--without altering malonate-induced TBARS production. Its antioxidant activity was abolished by KCN or heat treatment. Fumarate reduced malonate-induced TBARS production in fresh homogenates; however, its effect was completely abolished by heat treatment. There were minimal differences among the studied methods. Citrate, oxaloacetate, malate, alpha-ketoglutarate and malonate showed iron-chelating activity. We suggest that antioxidant properties of citrate, malate and oxaloacetate were due to their ability to cancel iron redox activity by forming inactive complexes, whereas alpha-ketoglutarate and malonate pro-oxidant activity can be due to formation of active complexes with iron. In contrast, succinate and fumarate antioxidant activity was probably due to some enzymatic system.

Study of safe usage of high-flow three-way stopcocks in a blood circuit

To examine the safety of using a high-flow three-way stopcock in a blood circuit during extracorporeal blood purification therapy, we studied the risk of development of hemolysis and clot formation in both ex vivo and in vivo extracorporeal circulation. In the ex vivo study, no significant difference was observed in the decrease in hematocrit (HCT) or increase in the potassium level between the three-way stopcock group and the control group. Nor was there a significant difference in the change in inlet pressure between the two groups. Thus, it was shown that the risk of hemolysis caused by the use of a high-flow three-way stopcock on both the outlet side and inlet side would be small. In the in vivo cases, there was no significant difference in the decrease in HCT or the increase in inlet pressure between the three-way stopcock group and control group, suggesting that it is clinically possible to incorporate a high-flow three-way stopcock into a blood circuit.

The Dose of Nafamostat Mesilate During Plasma Exchange With Continuous Hemodiafiltration in the Series-Parallel Circuit

We studied nafamostat mesilate (NM) and interleukin (IL)-18 levels to determine whether the dose of NM is reduced during plasma exchange (PE) with continuous hemodiafiltration (CHDF) when the series-parallel circuit is used. The subjects of the current study included four patients with acute hepatic failure who underwent PE with CHDF. The four patients underwent a total 15 PE + CHDF procedures, and for each procedure, they were randomized to receive either a half-dose of NM or no NM in the CHDF circuit. Eight procedures were carried out with NM administration, and seven were carried out without NM administration. The dose of NM in the NM group was significantly higher than that in the non-NM group (P = 0.040). No significant differences were observed between the two groups in the inlet NM concentration, the outlet NM concentration, or the rate of IL-18 removal. No statistical correlation was observed between the IL-18 level and the NM dose, the inlet NM concentration, or the outlet NM concentration. There was no blood access difficulty such as catheter failure or clotting of the filter. Thus, it might be possible to carry out PE and CHDF with the series-parallel method without administration of NM in the CHDF circuit.