Outcome after wait-listing for emergency liver transplantation in acute liver failure: a single centre experience

Acute liver failure: a life-threatening disease

BACKGROUND

An estimated 200 to 500 patients develop life-threatening acute liver failure (ALF) in Germany each year. Only sparse data are currently available on the epidemiology and causes of this condition and on potential treatments for it. This article summarizes our current knowledge of the causes, clinical course, and treatment of ALF.

METHOD

We selectively reviewed the pertinent current literature on ALF from Germany and abroad.

RESULTS

A shift is currently taking place in Germany with respect to the predominant causes of ALF: The leading cause was formerly acute viral hepatitis, but now more cases of ALF are induced by toxic substances, while there is also a growing incidence of cryptogenic subacute ALF. Precise epidemiological data are still lacking. Scoring -systems for the assessment of ALF should take account of hepatic function, the regenerative capacity of the liver, the extent of existing extrahepatic complications, and the risk that further ones will develop. The mortality from ALF has been reduced through improved specific treatment for certain etiological types of ALF, the introduction of liver transplantation, and progress in intensive care medicine. The optimal treatment of ALF patients requires close collaboration among specialists in all of the involved clinical disciplines, as well as between peripheral hospitals and transplantation centers.

CONCLUSION

Precise epidemiological data on ALF are still lacking in Germany, as are prospective, randomized trials of treatments for it. It is nonetheless clear that progress has been made in its diagnosis and treatment.

Acute liver failure: a life-threatening disease

BACKGROUND

An estimated 200 to 500 patients develop life-threatening acute liver failure (ALF) in Germany each year. Only sparse data are currently available on the epidemiology and causes of this condition and on potential treatments for it. This article summarizes our current knowledge of the causes, clinical course, and treatment of ALF.

METHOD

We selectively reviewed the pertinent current literature on ALF from Germany and abroad.

RESULTS

A shift is currently taking place in Germany with respect to the predominant causes of ALF: The leading cause was formerly acute viral hepatitis, but now more cases of ALF are induced by toxic substances, while there is also a growing incidence of cryptogenic subacute ALF. Precise epidemiological data are still lacking. Scoring -systems for the assessment of ALF should take account of hepatic function, the regenerative capacity of the liver, the extent of existing extrahepatic complications, and the risk that further ones will develop. The mortality from ALF has been reduced through improved specific treatment for certain etiological types of ALF, the introduction of liver transplantation, and progress in intensive care medicine. The optimal treatment of ALF patients requires close collaboration among specialists in all of the involved clinical disciplines, as well as between peripheral hospitals and transplantation centers.

CONCLUSION

Precise epidemiological data on ALF are still lacking in Germany, as are prospective, randomized trials of treatments for it. It is nonetheless clear that progress has been made in its diagnosis and treatment.

Does cytochrome P450 liver isoenzyme induction increase the risk of liver toxicity after paracetamol overdose?

Paracetamol (acetaminophen, N-acetyl-p-aminophenol, 4-hydroxyacetanilide) is the most common cause of acute liver failure in developed countries. There are a number of factors which potentially impact on the risk of an individual developing hepatotoxicity following an acute paracetamol overdose. These include the dose of paracetamol ingested, time to presentation, decreased liver glutathione, and induction of cytochrome P450 (CYP) isoenzymes responsible for the metabolism of paracetamol to its toxic metabolite N-acetyl-p-benzoquinoneimine (NAPQI). In this paper, we review the currently published literature to determine whether induction of relevant CYP isoenzymes is a risk factor for hepatotoxicity in patients with acute paracetamol overdose. Animal and human in vitro studies have shown that the CYP isoenzyme responsible for the majority of human biotransformation of paracetamol to NAPQI is CYP2E1 at both therapeutic and toxic doses of paracetamol. Current UK treatment guidelines suggest that patients who use a number of drugs therapeutically should be treated as “high-risk” after paracetamol overdose. However, based on our review of the available literature, it appears that the only drugs for which there is evidence of the potential for an increased risk of hepatotoxicity associated with paracetamol overdose are phenobarbital, primidone, isoniazid, and perhaps St John’s wort. There is no evidence that other drugs often quoted as increasing risk, such as carbamazepine, phenytoin, primidone, rifampicin, rifabutin, efavirenz, or nevirapine, should be considered risk factors for hepatotoxicity in patients presenting with acute paracetamol overdose.

Epidemiology of liver failure

The etiology of fulminant hepatitis varies in different countries and at different times. The main causes of fulminant hepatitis are viruses, paracetamol, drugs (other than paracetamol), poisons and 15-30% remained of undetermined origin. The prevalence of these etiologies varies according to the geographic region and has changed over the past 10 years. Paracetamol has now overtaken viruses (particularly hepatitis B virus) as the leading cause of fulminant hepatitis. Establishing the cause of fulminant hepatitis is an important step in the management of acute liver failure, so that specific therapy can be initiated and any contraindications to liver transplantation be eliminated.

Bridging Therapies and Liver Transplantation in Acute Liver Failure; 10 Years of MARS Experience from Finland

Acute liver failure is a life-threatening condition in the absence of liver transplantation option. The aetiology of liver failure is the most important factor determining the probability of native liver recovery and prognosis of the patient. Extracorporeal liver assist devices like MARS (Molecular Adsorbent Recirculating System) may buy time for native liver recovery or serve as bridging therapy to liver transplantation, with reduced risk of cerebral complications. MARS treatment may alleviate hepatic encephalopathy even in patients with a completely necrotic liver. Taking this into account, better prognostic markers than hepatic encephalopathy should be used to assess the need for liver transplantation in acute liver failure.

Serum levels of platelet-derived growth factor-BB and vascular endothelial growth factor as prognostic factors for patients with fulminant hepatic failure

BACKGROUND AND AIMS

In animal models for acute liver injury, the administration of some angiogenic factors such as vascular endothelial growth factor (VEGF) and granulocyte-colony stimulating factor (G-CSF) are shown to reduce liver injury and improve liver proliferative capacity. The aim of the present study was to assess the role of angiogenic factors in fulminant hepatic failure (FHF).

METHODS

Serum levels of nine angiogenic factors (angiopoietin-2, follistatin, G-CSF, hepatocyte growth factor [HGF], interleukin-8, leptin, platelet-derived growth factor [PDGF]-BB, platelet endothelial cell adhesion molecule-1 and VEGF) were measured using the Bio-Plex Protein Array System in 30 patients, 17 of whom were diagnosed with FHF, 13 with acute hepatitis (AH), and 20 controls.

RESULTS

Serum levels of PDGF-BB and VEGF were lower in FHF patients than AH patients and controls (PDGF-BB; 2050±1572 pg/mL vs 4521±2419 pg/mL vs 8506±5500 pg/mL, VEGF; 39±38 pg/mL vs 144±122 pg/mL vs 205±121 pg/mL). By using univariate logistic regression models, serum levels of PDGF-BB and VEGF were associated with poor outcomes. Serum PDGF-BB levels were strongly correlated with serum VEGF levels (r=0.70). Furthermore, serum PDGF-BB levels were significantly correlated with platelet counts (r=0.79), PT activity (r=0.37) and D.Bil/T.Bil ratio (r=0.50), while serum VEGF levels were significantly correlated with platelet counts (r=0.68) and PT activity (r=0.38).

CONCLUSIONS

We consider that serum levels of PDGF-BB and VEGF are worth investigating as biomarkers for predicting outcomes of FHF patients.

Meta-analysis of performance of Kings's College Hospital Criteria in prediction of outcome in non-paracetamol-induced acute liver failure

BACKGROUND & AIMS

Current techniques for predicting outcome and requirement for emergency liver transplantation (ELT) in acute liver failure (ALF) are imperfect, though The Kings College Criteria (KCC) are the most commonly applied tools for this purpose. Their performance in identification of patients with non-paracetamol-induced ALF (non-POD ALF), who would not survive without ELT, has recently been questioned. Using quantitative techniques, we therefore performed a meta-analysis of outcome data of the KCC for prediction of survival in non-POD ALF.

METHODS

A systematic database search was performed and retrieved articles graded according to a pre-agreed pro-forma of methodological quality. Collated data was meta-analysed for summary sensitivity, specificity, diagnostic odds ratio (DOR) and ROC curve analysis. Pre-specified sub-group analysis was performed on the basis of methodological quality, the severity of hepatic encephalopathy (HE) of reported patients, timing of KCC application and exclusion of those who underwent ELT.

RESULTS

Eighteen studies with data on 1105 patients were available for production of 2x2 tables. Summary sensitivity was 68 (95% CI 59-77)%, specificity 82 (75-88)% and DOR 12.6 (6.5-26.1). Heterogeneity was detected in the DOR and related to methodological quality (I(2)=64% for all studies versus 47% for 'good' quality studies) and was lower in studies considering high grade HE or dynamic application of KCC (I(2)=0%). For data where ELT were excluded (13 studies) summary sensitivity was 68 (57-79)%, specificity 81 (72-90)% and DOR 12.2 (4.9-30.1) and a symmetric summary ROC curve was produced. Specificity was highest in studies of patients with high grade HE (93 (80-100)%) and where KCC were applied dynamically through the clinical course (88 (78-97)%). Sensitivity was reduced in studies published post 2005 compared with studies pre 1995 (58 (46-71)% versus 85 (76-82)%).

CONCLUSIONS

KCC for outcome in non-POD ALF have good specificity and more limited sensitivity. There is significant heterogeneity in the published data partially related to methodological quality. KCC perform best in groups with high grade encephalopathy and in historically earlier studies suggesting modern medical management of ALF may modify performance of KCC.

Acute liver failure

Acute liver failure is a rare disorder with high mortality and resource cost. In the developing world, viral causes predominate, with hepatitis E infection recognised as a common cause in many countries. In the USA and much of western Europe, the incidence of virally induced disease has declined substantially in the past few years, with most cases now arising from drug-induced liver injury, often from paracetamol. However, a large proportion of cases are of unknown origin. Acute liver failure can be associated with rapidly progressive multiorgan failure and devastating complications; however, outcomes have been improved by use of emergency liver transplantation. An evidence base for practice is emerging for supportive care, and a better understanding of the pathophysiology of the disorder, especially in relation to hepatic encephalopathy, will probably soon lead to further improvements in survival rates.

Review article: the current management of acute liver failure

BACKGROUND

Acute liver failure is a devastating clinical syndrome with a persistently high mortality rate despite critical care advances. Orthotopic liver transplantation (OLT) is a life-saving treatment in selected cases, but effective use of this limited resource requires accurate prognostication because of surgical risks and the requirement for subsequent life-long immunosuppression.

AIM

To review the aetiology of acute liver failure, discuss the evidence behind critical care management strategies and examine potential treatment alternatives to OLT.

METHODS

Literature review using Ovid, PubMed and recent conference abstracts.

RESULTS

Paracetamol remains the most common aetiology of acute liver failure in developed countries, whereas acute viral aetiologies predominate elsewhere. Cerebral oedema is a major cause of death, and its prevention and prompt recognition are vital components of critical care support, which strives to provide multiorgan support and 'buy time' to permit either organ regeneration or psychological and physical assessment prior to acquisition of a donor organ. Artificial liver support systems do not improve mortality in acute liver failure, whilst most other interventions have limited evidence bases to support their use.

CONCLUSION

Acute liver failure remains a truly challenging condition to manage, and requires early recognition and transfer of patients to specialist centres providing intensive, multidisciplinary input and, in some cases, OLT.

Outcome of acute liver failure in the elderly

Older age is considered a poor prognostic factor in acute liver failure (ALF) and may still be considered a relative contraindication for liver transplantation for ALF. We aimed to evaluate the impact of older age, defined as age > or = 60 years, on outcomes in patients with ALF. One thousand one hundred twenty-six consecutive prospective patients from the US Acute Liver Failure Study Group registry were studied. The median age was 38 years (range, 15-81 years). One thousand sixteen patients (90.2%) were younger than 60 years (group 1), and 499 (49.1%) of these had acetaminophen-induced ALF; this rate of acetaminophen-induced ALF was significantly higher than that in patients > or = 60 years (group 2; n = 110; 23.6% with acetaminophen-induced ALF, P < 0.001). The overall survival rate was 72.7% in group 1 and 60.0% in group 2 (not significant) for acetaminophen patients and 67.9% in group 1 and 48.2% in group 2 for non-acetaminophen patients (P < 0.001). The spontaneous survival rate (ie, survival without liver transplantation) was 64.9% in group 1 and 60.0% in group 2 (not significant) for acetaminophen patients and 30.8% in group 1 and 24.7% in group 2 for non-acetaminophen patients (P = 0.27). Age was not a significant predictor of spontaneous survival in multiple logistic regression analyses. Group 2 patients were listed for liver transplantation significantly less than group 1 patients. Age was listed as a contraindication for transplantation in 5 patients. In conclusion, in contrast to previous studies, we have demonstrated a relatively good spontaneous survival rate for older patients with ALF when it is corrected for etiology. However, overall survival was better for younger non-acetaminophen patients. Fewer older patients were listed for transplantation.

Aetiology and outcome of acute liver failure

BACKGROUND

Acute liver failure (ALF) is a clinical syndrome characterized by the sudden onset of coagulopathy and encephalopathy. The outcome is unpredictable and is associated with high morbidity and mortality. We reviewed our experience to identify the aetiology and study the outcome of acute liver failure.

METHODS

A total of 1237 patients who presented with acute liver failure between January 1992 and May 2008 were included in this retrospective study. Liver transplantation was undertaken based on the King's College Hospital criteria. Data were obtained from the units prospectively collected database. The following parameters were analysed: patient demographics, aetiology, operative intervention, overall outcome, 30-day mortality and regrafts.

RESULTS

There were 558 men and 679 women with a mean age of 37 years (range: 8-78 years). The most common aetiology was drug-induced liver failure (68.1%), of which 90% was as a result of a paracetamol overdose. Other causes include seronegative hepatitis (15%), hepatitis B (2.6%), hepatitis A (1.1%), acute Budd-Chiari syndrome (1.5%), acute Wilson's disease (0.6%), subacute necrosis(3.2%) and miscellaneous (7.8%). Three hundred and twenty-seven patients (26.4%) were listed for liver transplantation, of which 263 patients successfully had the procedure (80.4%). The current overall survival after transplantation was 70% with a median follow-up of 57 months. After transplantation for ALF, the 1-year, 5-year and 10-year survival were 76.7%, 66% and 47.6%, respectively. The 30-day mortality was 13.7%. Out of the 974 patients who were not transplanted, 693 patients are currently alive. Among the 281 patients who died without transplantation, 260 died within 30 days of admission (26.7%). Regrafting was performed in 31 patients (11.8%), the most common indication being hepatic artery thrombosis (11 patients).

CONCLUSION

Paracetamol overdose was the most common cause of acute liver failure. Liver transplantation, when performed for acute liver failure, has good long-term survival.