Early therapeutic plasma exchange may improve treatment outcomes in severe acute toxic Hepatitis

Extra-corporeal non-liver transplant therapies for acute liver failure: Focus on plasma exchange and continuous renal replacement therapy

The acute inflammatory milieu in patients with acute liver failure (ALF) results in 'toxic' blood in these patients. In vitro experiments have shown that the plasma obtained from ALF patients is toxic to rabbit hepatocytes and inhibits regeneration of rat hepatocytes. Treatments such as plasma exchange and continuous renal replacement therapy to cleanse the blood have improved survival in ALF patients. In the liver microcirculation, the exchange of fluid across fenestrae in liver sinusoidal endothelial cells (LSECs) is vital for proper functioning of hepatocytes. Clogging of the liver filter bed by inflammatory debris and cells ('traffic jam hypothesis') impeding blood flow in sinusoids may in turn reduce the exchange of fluid across LSEC fenestrae and cause dysfunction and necrosis of hepatocytes in ALF patients. In mouse model of paracetamol overdose, disturbances in microcirculation in the liver preceded the development of injury and necrosis of hepatocytes. This may represent a reversible pathophysiological mechanism in ALF which may be improved by the anti-inflammatory effect of plasma exchange. Wider access to urgent plasma exchange is a major advantage compared to urgent liver transplantation to treat ALF patients worldwide, especially so in resource constrained settings. Continuous hemo-filtration or dialysis is used to reduce ammonia levels and treat cerebral edema in ALF patients. In this review, we discuss the different modalities to cleanse the blood in ALF patients, with an emphasis on plasma exchange, from a hepatology perspective.

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.

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.