Epidemiology and outcomes of acute liver failure in Australia

Update on the management of acute liver failure

PURPOSE OF REVIEW

Acute liver failure (ALF) is a rare, life-threatening but potentially reversible clinical syndrome characterized by multiple organ failure secondary to the rapid loss of liver function. Key management challenges include severe cerebral oedema and complex treatments to support multiple organ failure. This review focuses on the fundamental principles of management and recent treatment advances.

RECENT FINDINGS

Identifying the cause of ALF is key to guiding specific therapies. The early commencement of continuous renal replacement therapy (CRRT) to control hyperammonaemia can now be considered an important standard of care, and plasma exchange may have a role in the sickest of ALF patients; however, other blood purification modalities still lack supporting evidence. Close monitoring, regular investigations, careful attention to neuroprotective measures, as well as optimizing general physiological supports is essential. Where possible, patients should be transferred to a liver transplant centre to achieve the best chance of transplant-free survival, or to undergo emergency liver transplantation if required.

SUMMARY

This review outlines current principles of ALF management, emerging treatment strategies, and a practical approach to management in the ICU. These recommendations can form the development of local guidelines, incorporating current best evidence for managing this rare but often lethal condition.

Metabolic Reprograming of Macrophages: A New Direction in Traditional Chinese Medicine for Treating Liver Failure

Acute liver failure (ALF) is a fulminant clinical syndrome that usually leads to multiple organ failure and high mortality. Macrophages play a crucial role in the initiation, development, and recovery of ALF. Targeting macrophages through immunotherapy holds significant promise as a therapeutic strategy. These cells exhibit remarkable plasticity, enabling them to differentiate into various subtypes based on changes in their surrounding microenvironment. M1-type macrophages are associated with a pro-inflammatory phenotype and primarily rely predominantly on glycolysis. In contrast, M2-type macrophages, which are characterized by anti-inflammatory phenotype, predominantly obtain their energy from oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO). Shifting macrophage metabolism from glycolysis to OXPHOS inhibits M1 macrophage activation and promotes M2 macrophage activation, thereby exerting anti-inflammatory and reparative effects. This study elucidates the relationship between macrophage activation and glucose metabolism reprograming from an immunometabolism perspective. A comprehensive literature review revealed that several signaling pathways may regulate macrophage polarization through energy metabolism, including phosphatidyl-inositol 3-kinase/protein kinase B (PI3K/AKT), mammalian target of rapamycin (mTOR)/hypoxia-inducible factor 1α (HIF-1α), nuclear factor-κB (NF-κB), and AMP-activated protein kinase (AMPK), which exhibit crosstalk with one another. Additionally, we systematically reviewed several traditional Chinese medicine (TCM) monomers that can modulate glucose metabolism reprograming and influence the polarization states of M1 and M2 macrophages. This review aimed to provide valuable insights that could contribute to the development of new therapies or drugs for ALF.

Impact of Share 35 liver transplantation allocation in Australia and New Zealand

Patients with high model for end-stage liver disease (MELD) scores waiting for liver transplantation in Australia and New Zealand (ANZ) have had limited access to deceased donor livers and therefore binational sharing of livers, for patients with a MELD score ≥35 was introduced in February 2016. Waiting list mortality, post-transplant outcomes and intention-to-treat survival were compared between patients whose MELD score reached 35 on the waiting list between October 2013 and April 2015 (Pre-Share 35 group, n = 23) and patients who were Share 35 listed between February 2016 and May 2022 (Share 35 group, n = 112). There was significantly reduced waiting list mortality in share 35 listed patients in comparison to the pre-Share 35 group (11.7% vs. 52.2%, OR .120 95% CI .044-.328, P < .001). Post-transplant patient and graft survival were not significantly different between the groups (5-year patient survival 82% vs. 84%, P = .991, 5-year graft survival 82% vs. 76%, P = .543). Intention-to-treat survival was superior in the Share 35 group (HR .302, 95% CI .149-.614, P < .001). Introduction of Share 35 in ANZ resulted in a 78% risk reduction in waiting list mortality, equivalent post-transplant survival and an improvement in intention-to-treat survival.

Indeterminate etiology of acute liver failure in North America: Less common, still grave prognosis

BACKGROUND

The etiology of acute liver failure (ALF) remains one of the most important factors in determining prognosis and predicting outcomes. In a significant proportion of ALF cases, however, the etiology remains unknown and is categorized as indeterminate ALF (IND-ALF). In this study, we summarize findings from patients with IND-ALF from 32 transplant centers across the United States, and we compare laboratory, prognostic, and outcome data for patients with IND-ALF.

METHODS

Between 1998 and 2019, 3364 adult patients with ALF or acute liver injury (ALI) from 32 liver transplant centers were enrolled in the ALFSG registry. The primary clinical outcome of interest was 21-day transplant-free survival (TFS).

RESULTS

Of the 3364 patients enrolled in the ALFSG registry, 3.4 % (n = 114) were adjudicated as true indeterminate. On multivariate analysis, patients with a lower bilirubin, lower INR, lack of use of mechanical ventilation and no clinical features of coma at baseline had a higher odds ratio of transplant free survival. The number of deaths were similar between patients with true-IND ALF versus patients with indeterminable ALF (29.8% vs. 27.2%), with almost half of the patients requiring liver transplant (42.1% vs. 45.7%).

CONCLUSION

We illustrate the poor prognoses that true-IND-ALF and indeterminable ALF carry and the need for emergency liver transplantation in most cases.

Relapsed nodular lymphocyte-predominant Hodgkin lymphoma presenting as severe paraneoplastic hepatitis: a case report

BACKGROUND

Hematological malignancies are an infrequent but important cause of liver dysfunction. There are several mechanisms by which this can occur, including direct malignant infiltration of the hepatic parenchyma and/or vasculature, vanishing bile duct syndrome, and paraneoplastic hepatitis. Paraneoplastic hepatitis is an extremely rare mechanism by which a hematological malignancy can cause liver dysfunction, and we present the first case, to our knowledge, of paraneoplastic hepatitis caused by nodular lymphocyte-predominant Hodgkin lymphoma in the literature.

CASE PRESENTATION

A 28-year-old Caucasian male presented with 3 weeks of fatigue, epigastric pain, and jaundice. His medical history was significant for early stage nodular lymphocyte-predominant Hodgkin lymphoma in the cervical region in remission for 5 years after primary treatment with involved-field radiotherapy. Liver biochemistry was normal at the time of treatment for lymphoma and there was no known liver disease before the current presentation. On physical examination, there was scleral icterus and ecchymoses, but no evidence of hepatic encephalopathy, other stigmata of chronic liver disease, or lymphadenopathy. A computed tomography scan of his neck, chest, abdomen, and pelvis showed heterogeneous enhancement of the liver, multiple enlarged upper abdominal lymph nodes, and an enlarged spleen with multiple rounded lesions. Portal and hepatic veins were patent. Initial workup for viral, autoimmune-, toxin-, and medication-related hepatitis was negative. A transjugular liver biopsy was performed with histology showing a predominantly T-cell mediated hepatitis with very extensive multiacinar hepatic necrosis, but no evidence of lymphoma within the liver. Retroperitoneal lymph node biopsy revealed nodular lymphocyte-predominant Hodgkin lymphoma. The patient's symptoms, bilirubin, and transaminases improved significantly after treatment with oral prednisolone and a staged introduction of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy.

CONCLUSIONS

Nodular lymphocyte-predominant Hodgkin lymphoma may cause paraneoplastic hepatitis. Physicians should be aware of the possibility of this life-threatening presentation and the importance of early liver biopsy and treatment before acute liver failure occurs. Interestingly, paraneoplastic hepatitis did not occur when nodular lymphocyte-predominant Hodgkin lymphoma was first diagnosed and confined to the cervical region, but was the presenting feature of the recurrence below the diaphragm.

Critical care hepatology: definitions, incidence, prognosis and role of liver failure in critically ill patients

Organ dysfunction or overt failure is a commonplace event in the critically ill affecting up to 70% of patients during their stay in the ICU. The outcome depends on the resolution of impaired organ function, while a domino-like deterioration of organs other than the primarily affected ones paves the way for increased mortality. “Acute Liver Failure” was defined in the 1970s as a rare and potentially reversible severe liver injury in the absence of prior liver disease with hepatic encephalopathy occurring within 8 weeks. Dysfunction of the liver in general reflects a critical event in “Multiple Organ Dysfunction Syndrome” due to immunologic, regulatory and metabolic functions of liver parenchymal and non-parenchymal cells. Dysregulation of the inflammatory response, persistent microcirculatory (hypoxic) impairment or drug-induced liver injury are leading problems that result in “secondary liver failure,” i.e., acquired liver injury without underlying liver disease or deterioration of preexisting (chronic) liver disease (“Acute-on-Chronic Liver Failure”). Conventional laboratory markers, such as transaminases or bilirubin, are limited to provide insight into the complex facets of metabolic and immunologic liver dysfunction. Furthermore, inhomogeneous definitions of these entities lead to widely ranging estimates of incidence. In the present work, we review the different definitions to improve the understanding of liver dysfunction as a perpetrator (and therapeutic target) of multiple organ dysfunction syndrome in critical care.

Graphic Abstract

Epidemiology of liver failure in Asia-Pacific region

The global burden of deaths caused by liver failure is substantial. The Asia-Pacific region is home to more than half of the global population and accounted for 62.6% of global deaths because of liver diseases in 2015. The aetiology of liver failure varies in different countries at different times. Viruses (Hepatitis A, B and E), drugs (herbs and anti-tuberculous drugs), toxins (alcohol use) and autoimmune flares are mainly responsible of majority of liver failure in individuals with normal liver (acute liver failure; ALF); else these may precipitate liver failure in those with chronic liver disease (acute-on-chronic liver failure; ACLF). Concomitant increases in alcohol misuse and metabolic syndrome in recent years are concerning. Ongoing efforts to address liver failure-related morbidity and mortality require accurate contemporary estimates of epidemiology and outcomes. In light of the ever-changing nature of liver disease epidemiology, accurate estimates for the burden of liver failure across the countries are vital for setting clinical, research and policy priorities. In this review, we aimed to describe the current as well as changing epidemiological trends of common liver failure syndromes, ALF and ACLF in the Asia-Pacific region.

Acute liver failure

PURPOSE OF REVIEW

Present an outline of acute liver failure, from its definition to its management in critical care, updated with findings of selected newer research.

RECENT FINDINGS

Survival of patients with acute liver failure has progressively improved. Intracranial hypertension complicating hepatic encephalopathy is now much less frequent than in the past and invasive ICP monitoring is now rarely used. Early renal replacement therapy and possibly therapeutic plasma exchange have consolidated their role in the treatment. Further evidence confirms the low incidence of bleeding in these patients despite striking abnormalities in standard tests of coagulation and new findings of abnormalities on thromboelastographic testing. Specific coagulopathy profiles including an abnormal vWF/ADAMTS13 ratio may be associated with poor outcome and increased bleeding risk. Use of N-acetylcysteine in nonparacetamol-related cases remains unsupported by robust clinical evidence. New microRNA-based prognostic markers to select patients for transplantation are described but are still far from widespread clinical applicability; imaging-based prognostication tools are also promising. The use of extracorporeal artificial liver devices in clinical practice is yet to be supported by evidence.

SUMMARY

Medical treatment of patients with acute liver failure is now associated with significantly improved survival. Better prognostication and selection for emergency liver transplant may further improve care for these patients.

Acute Liver Failure Etiology Is an Independent Predictor of Waitlist Outcome but Not Posttransplantation Survival in a National Cohort

The impact of acute liver failure (ALF) etiology on waitlist (WL) and posttransplantation outcomes, independent of severity of illness, is incompletely characterized. All adults (n = 1691) listed for primary liver transplantation (LT) between 2002 and 2019 with ALF due to acetaminophen toxicity (APAP), drug-induced liver injury (DILI), autoimmune hepatitis (AIH), and hepatitis B virus (HBV) were identified in the United Network for Organ Sharing database. ALF etiology was evaluated as an independent predictor of WL mortality and spontaneous survival (SS; versus outcome of LT), as well as post-LT overall survival, graft survival, and in-hospital mortality using multivariable models accounting for differences in clinical parameters at listing. Accounting for severity of illness at listing, WL mortality and SS for DILI, AIH, and HBV were each lower than those for APAP toxicity (adjusted relative risk ratio <1 in all analyses with P < 0.001 for both outcomes). ALF etiology was not associated with adjusted overall survival after LT (P = 0.09) or graft survival (P = 0.13). Inpatient mortality rate after LT was high at 9.0%. While ALF etiology was also not associated with adjusted inpatient mortality (P = 0.42), cause of death (COD) was different. For example, the rate of post-LT brain death was 5.3% for APAP toxicity, 3.0% for other DILI, 1.1% for AIH, and 3.0% for HBV (P = 0.02). ALF etiology is an independent predictor of WL outcome, even after adjusting for severity of illness, but is not associated with post-LT outcomes with the exception of COD. The majority of post-LT deaths for all ALF etiologies studied occurred during the index hospital stay, suggesting a continued need for enhanced prognostic tools to ensure efficient organ utilization and ALF- and etiology-specific post-LT care to prevent brain death.

Variation in the Care of Acute Liver Failure: A Survey of Intensive Care Professionals

INTRODUCTION

Acute liver failure (ALF) is a rare disease with potentially high mortality. We sought to assess the individual approach to ALF by intensive care unit (ICU) professionals.

METHODS

Cross-sectional survey of ICU professionals. Web-based survey capturing data on respondents' demographics, characteristics of patients with ALF admitted to ICU, and their management.

RESULTS

Among 204 participants from 50 countries, 140 (68.6%) worked in Europe, 146 (71.6%) were intensivists, 142 (69.6%) admitted <25 patients with ALF per year, and 166 (81.8%) reported <25% of patients had paracetamol-related ALF. On patients' outcomes, 126 (75.0%) reported an emergency liver transplantation (ELT) rate <25% and 140 (73.3%) a hospital mortality rate <50%. The approach to ALF in the ICU varied with age, region, level of training, type of hospital, and etiology (prescribing N-acetylcysteine for paracetamol toxicity, triggers for endotracheal intubation, measurement of and strategies for lowering serum ammonia, extracorporeal device deployment, and prophylactic antibiotics).

CONCLUSIONS

The management of patients with ALF by ICU professionals differed substantially concerning the relevant clinical measures taken. Further education and high-quality research are warranted.

Acetaminophen Poisoning

Acetaminophen is a common medication taken in deliberate self-poisoning and unintentional overdose. It is the commonest cause of severe acute liver injury in Western countries. The optimal management of most acetaminophen poisonings is usually straightforward. Patients who present early should be offered activated charcoal and those at risk of acute liver injury should receive acetylcysteine. This approach ensures survival in most. The acetaminophen nomogram is used to assess the need for treatment in acute immediate-release overdoses with a known time of ingestion. However, scenarios that require different management pathways include modified-release, large/massive, and repeated supratherapeutic ingestions.

Current state of medical tourism involving liver transplantation-the risk of infections and potential complications

Liver transplant has been shown to significantly improve mortality and quality of life in various liver diseases such as acute liver failure, end-stage liver disease, and liver cancer. While the organ transplant demand is continuing to rise, the organ donation supply remains unmatched. The organ shortage, high cost, and long waiting lists have stimulated a desire for routes that may be unethical. This process which is named transplant tourism is the term used to describe traveling to another country to purchase an organ for transplant. Liver transplant tourism has been associated with post-transplant complications and higher mortality compared to a domestic liver transplant. Improper pre-and post-transplant infectious screening, inadequate opportunistic infection prophylaxis, and loss to follow-up were noted in patients who travel abroad for a liver transplant. It is crucial to understand the risk of transplant tourism to prevent morbidity and mortality.

Analysis of the Australia and New Zealand referral criteria for transfer to a liver unit for paracetamol overdose

OBJECTIVES

Paracetamol overdose is common and can lead to fulminant hepatic failure. In cases that are not improving with standard medical therapy with N-acetylcysteine, some patients may require liver transplant. The Australia and New Zealand (ANZ) referral criteria for transfer to a liver unit have not been extensively studied for its predictive value. The aim of this study was to evaluate the ANZ referral criteria for predicting mortality in paracetamol overdose.

METHODS

This study involves a retrospective analysis of patients who developed hepatotoxicity post-paracetamol overdose presenting to an Australian health service with a liver transplant unit between 2010 and 2019 and were treated with N-acetylcysteine. The primary outcome was death or transplant.

RESULTS

Out of 983 paracetamol overdose presentations, 81 (8.2%) cases developed hepatotoxicity. Of these, 17 cases (21%) met the composite endpoint of death or transplant. The ANZ referral criteria is highly sensitive at predicting the primary endpoint of death or transplant at time of referral 100% (95% confidence interval 81-100) but had low specificity at 30% (95% confidence interval 19-42).

CONCLUSIONS

The ANZ referral criteria were highly sensitive for predicting the outcome of mortality and transplant. This is important for screening patients who may become unstable and difficult to transfer at a later stage of their admission.

Efficacy and safety of liver support devices in acute and hyperacute liver failure: a systematic review and network meta-analysis

Acute liver failure (ALF) is a potentially life-threatening condition. Liver support therapies can be applied as a bridging-to-transplantation or bridging-to-recovery; however, results of clinical trials are controversial. Our aim was to compare liver support systems in acute and hyperacute liver failure with network meta-analysis. After systematic search, randomized controlled trials (RCT) comparing liver support therapies in adults with acute or hyperacute liver failure were included. In-hospital mortality was the primary outcome, the secondary outcomes were hepatic encephalopathy and mortality-by-aetiology. A Bayesian-method was used to perform network meta-analysis and calculate surface under the cumulative ranking curve (SUCRA) values to rank interventions. Eleven RCTs were included. BioLogic-DT and molecular adsorbent recirculating system (MARS) resulted in the lowest mortality (SUCRAs: 76% and 73%, respectively). In non-paracetamol-poisoned patients, BioLogic-DT, charcoal hemoperfusion and MARS may be equally efficient regarding mortality (SUCRAs: 53%, 52% and 52%, respectively). Considering hepatic encephalopathy, extracorporeal liver assist device (ELAD) may be the most effective option (SUCRA: 78%). However, in pairwise meta-analysis, there were no statistically significant differences between the interventions in the outcomes. In conclusion, MARS therapy seems to be the best available option in reducing mortality. Further research is needed on currently available and new therapeutic modalities. (CRD42020160133).

Etiology, clinical presentation, and outcome of children with fulminant hepatic failure: Experience from a tertiary center in Pakistan

OBJECTIVES

To determine etiologies, clinical presentations and outcomes of children with fulminant hepatic failure in the first liver transplant center of Pakistan.

METHODS

It was a retrospective, observational study, conducted in Paediatric Gastroenterology Department of Shifa International Hospital. Patients between one month to 16 years were included who fulfilled the Pediatric Acute Liver Failure study group (PALFSG) definition of acute liver failure as biochemical evidence of liver injury with no known co-existing chronic liver disease, coagulopathy not corrected by vitamin K, an International Normalized Ratio (INR) greater than 1.5 if the patient has encephalopathy, or greater than 2.0 if the patient does not have encephalopathy. The data collected was recorded on a self-constructed proforma after IRB approval.

RESULTS

There were 28 patients in the study which ncluded 17 males and 11 females with a mean age of 72.86±52.50 months. The most common etiologies were Hepatitis A (29%) in isolation or co-infection with Wilson Disease, typhoid fever. It was followed by seronegative hepatitis (29%). Majority (64%) had acute presentation (7 to 28 days), jaundice (82%) being the most common symptom. Severity of encephalopathy was significantly associated with outcome (p=0.02). There were 6 (21%) patients who succumbed to death.

CONCLUSIONS

The study highlights infective diseases as the predominant etiology causing fulminant liver failure in children. Our study highlights lower mortality in children.