Emergency liver transplantation for fulminant liver failure in infants and children

Proceedings of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition Monothematic Conference, 2020: "Acute Liver Failure in Children": Treatment and Directions for Future Research

OBJECTIVES

The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology.

METHODS

The 2020 single topic ESPGHAN monothematic 3-day conference on pediatric liver disease, was organized in Athens, Greece and was entitled " Acute Liver Failure" (ALF). ALF is a devastating disease with high mortality and in a considerable fraction of patients, the cause remains unresolved. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with developments in medical therapy and indications for liver transplantation (LT) and to identify areas for future research in clinical and neurocognitive outcomes in ALF.

RESULTS

We recently reported the epidemiology, diagnosis, and initial intensive care management issues in separate manuscript. Herewith we report on the medical treatment, clinical lessons arising from pediatric studies, nutritional and renal replacement therapy (RRT), indications and contraindications for LT, neurocognitive outcomes, new techniques used as bridging to LT, and areas for future research. Oral presentations by experts in various fields are summarized highlighting key learning points.

CONCLUSIONS

The current report summarizes the current insights in medical treatment of pediatric ALF and the directions for future research.

Hepatic Manifestations of Nonhepatotropic Infectious Agents Including Severe Acute Respiratory Syndrome Coronavirus-2, Adenovirus, Herpes Simplex Virus, and Coxiella burnetii

Nonhepatotropic viruses such as adenovirus, herpes simplex virus, flaviviruses, filoviruses, and human herpes virus, and bacteria such as Coxiella burnetii, can cause liver injury mimicking acute hepatitis. Most of these organisms cause a self-limited infection. However, in immunocompromised patients, they can cause severe hepatitis or in some cases fulminant hepatic failure requiring an urgent liver transplant. Hepatic dysfunction is also commonly seen in patients with severe acute respiratory syndrome coronavirus-2 infection. Patients with preexisting liver diseases are likely at risk for severe coronavirus disease 2019 (COVID-19) and may be associated with poor outcomes.

Admission Factor V Predicts Transplant-Free Survival in Acute Liver Failure

BACKGROUND AND AIMS

Traditional laboratory markers are insensitive in distinguishing between patients with acute liver failure (ALF) who will require urgent liver transplantation (LT) from those who will recover spontaneously, particularly within 24 h of presentation. Coagulation factor-V (FV) may improve the accuracy of outcome prediction in ALF due to its predominant synthesis in the liver and short half-life in plasma.

METHODS

Patients enrolled in the ALF Study Group Registry from a single site had FV determined within 24 h of presentation (Derivation-Cohort). Area under the receiver operating characteristic curves (AUROC) dichotomized by ALF etiology [acetaminophen (APAP) or non-APAP] were constructed to evaluate the diagnostic performance of FV for transplant-free-survival (TFS). Multivariate logistic regression modeling was performed using FV and other clinical variables to predict TFS. Accuracy of FV and multivariable model were performed in a Validation-Cohort from a different site.

RESULTS

90-patients (56% with APAP) were included in the Derivation-Cohort. Median FV was significantly higher in TFS versus those who died/LT (31% vs. 15%, respectively; p = 0.001). When dichotomized by etiology, AUROC for FV was 0.77 for APAP (cutoff, sensitivity, specificity 10.5%, 79%, 69%, respectively) and 0.77 for non-APAP (22%, 85%, 67%, respectively). When the optimal cutoffs for FV in the Derivation-Cohort were applied to the Validation-Cohort (N = 51; 59% with APAP), AUROC for FV was 0.75 for APAP (sensitivity/specificity 81/44) and 0.95 for non-APAP (sensitivity/specificity 90/73). In multivariate analyses, AUROC for FV model was 0.86 in the Derivation-Cohort and 0.90 in the Validation-Cohort.

CONCLUSION

Admission FV may improve selection of patients who are likely to improve without LT.

Etiologies, Prognostic Factors, and Outcomes of Pediatric Acute Liver Failure in Thailand

PURPOSE

Pediatric acute liver failure (PALF) is a serious condition; however, data on PALF in developing countries are sparse, particularly concerning molecular diagnosis and liver transplantation (LT). This study aimed to determine the causes, outcomes, and prognostic factors of PALF.

METHODS

We retrospectively reviewed the medical records of children (age <15 years) with PALF diagnosed using the American Association for the Study of Liver Diseases criteria at our center from 2011 to 2016. The collected data included laboratory results, complications, outcomes, and potential factors associated with death and LT.

RESULTS

We included a total of 27 patients, with a median age of 2 years (interquartile range, 3 months to 4 years). Viral infection was the most common etiology (n=8, 30%), predominantly dengue infection (n=4). A total of 16 patients (59%) died and 11 patients survived (3 patients with LT). The prognostic factors associated with death or LT requirement were grade IV hepatic encephalopathy (p<0.01), hypotension (p=0.02), gastrointestinal bleeding (p=0.03), increased intracranial pressure (p=0.04), and higher peak serum lactate level (p=0.01). Peak serum lactate ≥6 mmoL/L had a sensitivity of 79% and a specificity of 88% for predicting mortality or the necessity of LT.

CONCLUSION

Viral infection was the most common cause of PALF. The mortality rate remained high, and a considerable number of patients required LT. In addition to several clinical factors, peak serum lactate could be a potential marker for predicting poor outcomes in PALF.

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.

Neurocritical care monitoring of encephalopathic children with acute liver failure: A systematic review

Research on non-invasive neuromonitoring specific to PALF is limited. This systematic review identifies and synthesis the existing literature on non-invasive approaches to monitoring for neurological sequelae in patients with PALF. A series of literature searches were performed to identify all publications pertaining to five different non-invasive neuromonitoring modalities, in line with PRISMA guidelines. Each modality was selected on the basis of its potential for direct or indirect measurement of cerebral perfusion; studies on electroencephalographic monitoring were therefore not sought. Data were recorded on study design, patient population, comparator groups, and outcomes. A preponderance of observational studies was observed, most with a small sample size. Few incorporated direct comparisons of different modalities; in particular, comparison to invasive intracranial pressure monitoring was largely lacking. The integration of current evidence is considered in the context of the clinically significant distinctions between pediatric and adult ALF, as well as the implications for planning of future investigations to best support the evidence-based clinical care of these patients.

Acute Liver Failure: An Update

Pediatric acute liver failure (PALF) is a dynamic, life-threatening condition of disparate etiology. Management of PALF is dependent on intensive collaborative clinical care and support. Proper recognition and treatment of common complications of liver failure are critical to optimizing outcomes. In parallel, investigations to identify underlying cause and the implementation of timely, appropriate treatment can be life-saving. Predicting patient outcome in the era of liver transplantation has been unfulfilling and better predictive models must be developed for proper stewardship of the limited resource of organ availability.

Hepatitis caused by herpes viruses: A review

Herpes virus hepatitis varies in presentation, ranging from asymptomatic to acute liver failure, in both immunocompetent and immunocompromised individuals. Hepatitis caused by the Herpesviridae family is uncommon and usually results in mild disease. It is also often self-limiting, although in certain populations especially immunosuppressed patients, it can cause severe infections, leading to acute to fulminant hepatic failure. In addition, some isolated cases of fulminant disease in immunocompetent individuals have been reported. As the presentation is frequently non-specific, it is important to maintain a high level of suspicion for these viral etiologies and start empiric therapy with antiviral agents as soon as possible. Liver transplantation is the last resort. Mortality remains high in fulminant hepatic failure caused by Herpesviridae without liver transplantation. Here we review the literatures on hepatitis caused by three members of the Herpesviridae family, cytomegalovirus, Epstein-Barr virus and herpes simplex virus to discuss the epidemiology, diagnostic methods, clinical features and current management, and also to determine which aspects need to be investigated in further detail. Herpesviridae-mediated acute liver failure is rare but is associated with a poor prognosis, even after early treatment.

Effect of a Hybrid Liver Support System on Cardiopulmonary Function in Healthy Pigs

The aim of this study was to evaluate the effects of a hybrid liver support system (LSS) on cardiopulmonary function in nine healthy pigs. A hybrid LSS containing primary pig hepatocytes was connected to fully alert animals. The extracorporeal blood flow was maintained between 200-240 ml/min using a roller pump. Continuous plasma flow through the hybrid LSS was 50-60 ml/min. Hemodynamic and pulmonary gas exchange parameters were compared 1 hour before and 1 hour after connection to as well as 1 hour before and 1 hour after disconnection from the hybrid LSS. The hybrid LSS did not influence significantly hemodynamics and pulmonary gas exchange in this group of healthy and awake pigs. It can be concluded that the used LSS did not cause a cardiopulmonary effect per se and should be evaluated further concerning its function as a liver support system in an animal model of acute hepatic failure.

Novel NBAS mutations and fever-related recurrent acute liver failure in Chinese children: a retrospective study

Background

Underlying causes in Chinese children with recurrent acute liver failure (RALF), including liver crises less than full acute liver failure, are incompletely understood. We sought to address this by searching for genes mutated in such children.

Methods

Five unrelated Chinese boys presenting between 2012 and 2015 with RALF of unexplained etiology were studied. Results of whole exome sequencing were screened for mutations in candidate genes. Mutations were verified in patients and their family members by Sanger sequencing. All 5 boys underwent liver biopsy.

Results

NBAS was the only candidate gene mutated in more than one patient (biallelic mutations, 3 of 5 patients; 5 separate mutations). All NBAS mutations were novel and predictedly pathogenic (frameshift insertion mutation c.6611_6612insCA, missense mutations c.2407G > A and c.3596G > A, nonsense mutation c.586C > T, and splicing-site mutation c.5389 + 1G > T). Of these mutations, 3 lay in distal (C-terminal) regions of NBAS, a novel distribution.

Unlike the 2 patients without NBAS mutations, the 3 patients with confirmed NBAS mutations all suffered from a febrile illness before each episode of liver crisis (fever-related RALF), with markedly elevated alanine aminotransferase and aspartate aminotransferase activities 24-72 h after elevation of body temperature, succeeded by severe coagulopathy and mild to moderate jaundice.

Conclusions

As in other countries, so too in China; NBAS disease is a major cause of fever-related RALF in children. The mutation spectrum of NBAS in Chinese children seems different from that described in other populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-017-0636-3) contains supplementary material, which is available to authorized users.

Presenting Features and Prognosis of Ischemic and Nonischemic Neonatal Liver Failure

OBJECTIVES

To describe the epidemiological features, clinical characteristics and outcomes of neonates diagnosed with liver failure, as well as determine prognostic factors.

METHODS

Cohort study conducted at a single tertiary referral and university-affiliated pediatric center. Hospital records of all neonates diagnosed with liver failure between January 2003 and December 2015 were retrospectively reviewed, and data on clinical and laboratory findings, treatment, and outcomes were collected. Survival analysis (Kaplan-Meier) and Cox regression were performed to identify prognostic factors at diagnosis. Liver failure diagnosis was established using the pediatric acute liver failure study group's diagnostic criteria for every patient with coagulopathy and biochemical pattern of liver disease.

RESULTS

Forty-five patients were included. In our series, most cases were secondary to ischemia (28.9%). Other causes were neonatal hemochromatosis (17.8%), viral infections (13.3%), and inborn errors of metabolism (13.3%). A total 55.6% (25/45) of the patients died (median age: 16 days; range 1-235 days). Alanine aminotransferase (ALT) at diagnosis was associated with higher mortality or the need for liver transplantation on day 21 after diagnosis (P = .006). For every 500 IU/L increase in ALT serum levels, the mortality/liver transplantation rate increased 1.3 times (hazard ratio 95% confidence interval: 1.1-1.6). Although ischemic neonatal acute liver failure presents with higher ALT levels, these cases appear to have better outcomes. Higher international normalized ratio tended to increase mortality/transplantation (hazard ratio 1.02; 95% confidence interval 0.91-1.2).

CONCLUSIONS

Neonatal liver failure should perhaps be considered in the differential diagnoses of any coagulopathy. ALT and international normalized ratio levels at diagnosis could predict prognosis in the short term. Ischemic liver failure appears to have a better prognosis.

Liver transplantation for acute liver failure

Before liver transplantation became widely applicable as a treatment option, the mortality rate for acute liver failure was as high as 85%. Today, acute liver failure is a relatively common transplant indication in some settings, but the results of liver transplantation in this context appear to be worse than those for chronic forms of liver disease. In this review, we discuss the indications and contraindications for urgent liver transplantation. In particular, we consider the roles of auxiliary, ABO-incompatible, and urgent living donor liver transplantation and address the management of a «status 1» patient with total hepatectomy and portocaval shunt for toxic liver syndrome.

Prognostic modeling in pediatric acute liver failure

Liver transplantation (LT) is the only proven treatment for pediatric acute liver failure (PALF). However, over a period of time, spontaneous native liver survival is increasingly reported, making us wonder if we are overtransplanting children with acute liver failure (ALF). An effective prognostic model for PALF would help direct appropriate organ allocation. Only patients who would die would undergo LT, and those who would spontaneously recover would avoid unnecessary LT. Deriving and validating such a model for PALF, however, encompasses numerous challenges. In particular, the heterogeneity of age and etiology in PALF, as well as a lack of understanding of the natural history of the disease, contributed by the availability of LT has led to difficulties in prognostic model development. Several prognostic laboratory variables have been identified, and the incorporation of these variables into scoring systems has been attempted. A reliable targeted prognostic model for ALF in Wilson's disease has been established and externally validated. The roles of physiological, immunological, and metabolomic parameters in prognosis are being investigated. This review discusses the challenges with prognostic modeling in PALF and describes predictive methods that are currently available and in development for the future. Liver Transplantation 22 1418-1430 2016 AASLD.

Pediatric acute liver failure in Brazil: Is living donor liver transplantation the best choice for treatment?

Acute liver failure (ALF) in children is a life-threatening condition that often leads to urgent liver transplantation (LT). The aim of the present investigation was to describe the experience in Brazil in treating pediatric ALF, with an emphasis on the role of living donor liver transplantation (LDLT) in treating this condition. All children with ALF who fulfilled the criteria for an urgent LT were admitted to the intensive care unit. Patients were divided into 2 groups based on the moment of admission: before and after June 2007, when the LDLT program for ALF was started. Statistical analyses were performed to identify prognostic factors of patients with ALF. For the study, 115 children with ALF were admitted. All patients had some degree of encephalopathy. Among the patients, 26% of them required intracranial pressure monitoring (IPM), 12.8% of the patients required hemodialysis, and 79 patients underwent transplantation (50 deceased donors and 29 living donors) corresponding to 12.4% of all pediatric LTs. Only 9 children recovered without LT. The need for IPM and nonperformance of LT were related to a higher mortality. The mortality rate of patients who underwent LT was significantly lower than that of children with ALF who did not undergo a LT (48.1% versus 75%; P = 0.02). The incidences of primary nonfunction and mortality were statistically higher among deceased donor liver transplantations than LDLTs. Finally, it was verified that the overall survival rate of transplanted patients was increased after the introduction of LDLT (P = 0.02). In conclusion, ALF in children continues to be a severe and devastating condition, and a LT should be performed promptly. The introduction of LDLT could increase the survival rate of patients in Brazil. Liver Transplantation 22 1006-1013 2016 AASLD.

Pediatric acute liver failure: variations in referral timing are associated with disease subtypes

In pediatric acute liver failure (PALF), rapid referral to a transplant center (TC) is advocated. Clinical variability of PALF may influence referral timing. We aimed to analyze early or late timing of referral in relation to clinical characteristics and outcome in PALF. We conducted a retrospective, single-center, comparative analysis of clinical and liver function parameters in two PALF cohorts (n = 23 per cohort): cohort 1 (early referral, duration of in-patient care before referral (DCR) <7 days) vs. cohort 2 (late referral, DCR ≥ 7 days). Compared to late referrals, patients referred early were more frequently non-icteric and encephalopathic at initial presentation (n = 14 vs. 5 and n = 13 vs. 4, each p < 0.05). Early referred PALF patients had lower hepatic encephalopathy (HE) grades and bilirubin (grade 1 vs. 2, p < 0.02; 215 vs. 439 μmol/l, p < 0.001, respectively) but higher alanine aminotransferase (ALAT) levels (4,340 vs. 963 U/l, p < 0.001). Cumulative poor prognostic indicators were lower in early referrals (2 vs. 4, p < 0.001). In multivariate analysis, subacute liver failure (SLF >7 days between disease onset and development of encephalopathy) was independently associated with late referral (relative risk 9.48; 95 % CI 1.37-64.85, p < 0.02). Differences in survival to discharge were not significant.

CONCLUSION

In PALF, referral timing variability is associated with distinct clinical and liver function patterns. Early recognition of prognostic indicators and of SLF may help to improve referral timing and thus PALF management.

Analysis of viral testing in nonacetaminophen pediatric acute liver failure

OBJECTIVE

Viral infections are often suspected to cause pediatric acute liver failure (PALF), but large-scale studies have not been performed. We analyzed the results of viral testing among nonacetaminophen PALF study participants.

METHODS

Participants were enrolled in the PALF registry. Diagnostic evaluation and final diagnosis were determined by the site investigator and methods for viral testing by local standard of care. Viruses were classified as either causative viruses (CVs) or associated viruses (AVs). Supplemental testing for CV was performed if not done clinically and serum was available. Final diagnoses included "viral," "indeterminate," and "other."

RESULTS

Of 860 participants, 820 had at least 1 test result for a CV or AV. A positive viral test was found in 166/820 (20.2%) participants and distributed among "viral" (66/80 [82.5%]), "indeterminate" (52/420 [12.4%]), and "other" (48/320 [15.0%]) diagnoses. CVs accounted for 81/166 (48.8%) positive tests. Herpes simplex virus (HSV) was positive in 39/335 (11.6%) who were tested 26/103 (25.2%) and 13/232 (5.6%) among infants 0 to 6 and >6 months, respectively. HSV was not tested in 61.0% and 53% of the overall cohort and those 0 to 6 months, respectively. Supplemental testing yielded 17 positive, including 5 HSV.

CONCLUSIONS

Viral testing in PALF occurs frequently but is often incomplete. The evidence for acute viral infection was found in 20.2% of those tested for viruses. HSV is an important viral cause for PALF in all age groups. The etiopathogenic role of CV and AV in PALF requires further investigation.

Timing and benefit of liver transplantation in acute liver failure

The case for using emergency liver transplantation in acute liver failure was made two decades ago by a series of single centre experiences. The development of models identifying a poor prognosis assisted the selection of patients for liver transplantation but none of these delivers both high sensitivity and specificity for prediction of death. Enhanced sensitivity favours the individual patient while enhanced specificity targets the pool of organs available at those who will derive greatest benefit. The non-transplant survival rates have improved considerably for certain cohorts of patients and these prognostic models have not been adjusted to reflect these changes. The presumption of transplant benefit can no longer be taken as established in paracetamol-related acute liver failure and a policy review is appropriate. In other scenarios, such as seronegative hepatitis and the phenotype of sub-acute liver failure, spontaneous survival rates remain low and the basis for liver transplantation remains sound. Outcomes after liver transplantation are improving but are not yet comparable to elective transplantation. The understanding of factors associated with failure after liver transplantation is improving but accurate definition of futility has not yet been attained.

Differential clinical characteristics of acute liver failure caused by hemophagocytic lymphohistiocytosis in children

BACKGROUND

Children with acute liver failure (ALF) caused by hemophagocytic lymphohistiocytosis (HLH) may be at risk of undergoing unnecessary liver transplantation (LT). The aim of this study was to compare the characteristics of ALF caused by HLH with those of ALF of unknown etiology in children.

METHODS

The clinical features and laboratory findings for eight children with ALF caused by HLH (ALF-HLH group) and 27 children with ALF of unknown etiology (ALF-UK group) were retrospectively compared by reviewing medical records.

RESULTS

The ALF-HLH group had a higher incidence of pleural effusion, C-reactive protein elevation (especially >5 mg/dL), thrombocytopenia, anemia, fever, splenomegaly, and hypoalbuminemia (<2.5 mg/dL), and a higher in-hospital mortality rate. No significant differences were found in the white blood cell count, liver enzymes, coagulation profile, or incidence of hepatomegaly.

CONCLUSIONS

LT should be performed only after it is proven that ALF is not caused by HLH, if a child with ALF shows the differential clinical features of ALF caused by HLH. Further research with larger sample sizes, however, is needed.

Pediatric liver transplantation: where do we stand? Where we are going to?

Pediatric liver transplantation (LT) is one of the most successful solid organ transplants with long-term survival more than 80%. Many aspects have contributed to improve survival, especially advancements in pre-, peri- and post-transplant management. The development of new surgical techniques, such as split-LT and the introduction of living related LT, has extended LT to small infants. Progress in the last 30 years has also been characterized by the introduction of calcineurin inhibitors. One problem remains the lack of donors. Donation after cardiac death offers a new possibility to increase the pool of potential donors. In children with acute liver failure, increasing interest has centered on the possibility of providing temporary liver support based on extracorporeal devices or hepatocyte transplantation. Similarly, hepatocyte transplantation offers new perspective in children with metabolic failure. As long-term survival increases, attention has now focused on the quality of life achieved by children undergoing LT.

King's College Hospital Criteria for non-acetaminophen induced acute liver failure in an international cohort of children

OBJECTIVE

To validate King's College Hospital criteria (KCHC) in children with non-acetaminophen induced pediatric acute liver failure (PALF) and to determine whether re-optimizing the KCHC would improve predictive accuracy.

STUDY DESIGN

We used the PALF study group database. Primary outcomes were survival without liver transplantation vs death at 21 days following enrollment. Classification and regression tree analysis was used to determine if modification of KCHC parameters would improve classification of death vs survival.

RESULTS

Among 163 patients who met KCHC, 54 patients (33.1%) died within 21 days. Sensitivity of KCHC in this cohort was significantly lower than in the original study (61% vs 91%, P = .002), and specificity did not differ significantly. The positive predictive value (PPV) and negative predictive value (NPV) of KCHC for this cohort was 33% and 88% respectively. Classification and regression tree analysis yielded the following optimized parameters to predict death: grade 2-4 encephalopathy, international normalized ratio >4.02, and total bilirubin >2.02 mg/dL. These parameters did not improve PPV, but NPV was significantly better (88% vs 92%, P < .0001).

CONCLUSIONS

KCHC does not reliably predict death in PALF. With a PPV of 33%, twice as many participants who met KCHC recovered spontaneously than died, indicating that using KCHC may cause over utilization of liver transplantation. Re-optimized cutpoints for KCHC parameters improved NPV, but not PPV. Parameters beyond the KCHC should be evaluated to create a predictive model for PALF.

Liver transplantation for acute liver failure

Liver transplantation is now an integral part of the management of acute liver failure. The challenge for clinicians is to select the appropriate candidates with a combination of need and high likelihood of benefiting from the transplant. This is achieved through a combination of prognostic modelling and ongoing clinical evaluation. Although the outcomes after liver transplantation are good the survival rates do not quite match those achieved after elective transplantation.

Predictors of outcome in children with acute viral hepatitis and coagulopathy

The presence of coagulopathy in acute viral hepatitis (AVH) in children raises issues about prognosis and need for liver transplantation. We evaluated factors predicting outcome in such patients and determined the applicability of the paediatric acute liver failure study group (PALFSG) definition of acute liver failure (ALF) of coagulopathy alone in comparison with coagulopathy and encephalopathy. Children with AVH (clinical features, raised transaminases and positive viral serology) with uncorrectable coagulopathy [prothrombin time (PT) > 15 s] with or without hepatic encephalopathy (HE) were enrolled. Comparative analysis was based on (i) outcome: survivors/nonsurvivors and (ii) ALF criteria: group A coagulopathy (PT > 15 s) and encephalopathy and group B coagulopathy (PT > 20 s). We studied 130 children (86 boys, mean age 7.5 ± 4.5 years): 86 recovered and 44 died. Single virus infection was present in 96 (74%), hepatitis A being the commonest (n-69). On multiple stepwise logistic regression analysis, age <3.5 years, serum bilirubin ≥ 16.7 mg/dL, PT ≥ 40.5 s and clinical signs of cerebral oedema were independent predictors of mortality. Mortality increased from 0% with single to 100% with four risk factors. Ninety-seven cases met the PALFSG criteria: group A-79 and group B-18. Group A subjects had higher mortality (55.6%vs 0%) and poorer liver functions (bilirubin 18.1 ± 8.9 vs 13.8 ± 6.9 mg/dL, PT 63.9 ± 35.1 vs 27.2 ± 5.2 s) than group B. PT deteriorated significantly with the appearance and progression of HE. One-third of children with AVH with coagulopathy die without transplantation. Age <3.5 years, bilirubin ≥ 16.7 mg/dL, PT ≥ 40.5 s and signs of cerebral oedema are predictors of poor outcome. Children with encephalopathy and coagulopathy have a poorer outcome than those with coagulopathy alone.

Hodgkin disease relapse discovered at the time of liver transplant for acute liver failure

Lymphoma is a recognized cause of liver damage and in rare instances presents as ALF. In such cases, the underlying malignancy is often difficult to detect. Historically, the prognosis has been poor. Cure has occasionally been achieved with chemotherapy alone. LT in this setting is controversial, but has contributed to successful outcomes, as in the case of the five-yr-old girl reported here.

Acute liver failure in neonates, infants and children

Acute liver failure (ALF) is a rare but devastating syndrome. ALF in children differs from that observed in adults in both the etiologic spectrum and the clinical picture. Specific therapy to promote liver recovery is often not available and the underlying cause of the liver failure is often not determined. Management requires a multidisciplinary approach and should focus on preventing or treating complications and arranging for early referral to a transplant center. Although liver transplantation has increased the chance of survival, children who have ALF still face an increased risk of death, both while on the waiting list and after emergency liver transplantation. This article will review the current knowledge of the epidemiology, pathobiology and treatment of ALF in neonates, infants and children, and discuss some recent controversies.

Acute liver failure in children

The management of children with acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but clinical studies have mainly concerned adult patients. There are no specific medical therapies, except for a few metabolic diseases presenting with acute liver failure. Liver transplantation still remains the only definitive therapy in most instances. Recent clinical studies suggest that hepatocyte transplantation may be useful for bridging patients to liver transplantation, for providing metabolic support during liver failure and for replacing liver transplantation in certain metabolic liver diseases.

Continuous veno-venous single-pass albumin hemodiafiltration in children with acute liver failure

OBJECTIVE

To investigate the applicability, efficacy, and safety of single-pass albumin dialysis in children.

DESIGN

Retrospective data review of uncontrolled clinical data.

SETTING

University-based pediatric intensive care unit collaborating with a local center for liver transplantation.

PATIENTS

Nine children, aged 2 to 15 yrs, who were treated with single-pass albumin dialysis for acute liver failure of various origins under a compassionate-use protocol between 2000 and 2006. All patients met high-urgency liver transplantation criteria.

INTERVENTIONS

Single-pass albumin dialysis was performed as rescue therapy for children with acute liver failure.

MEASUREMENTS AND MAIN RESULTS

The decrease in hepatic encephalopathy (grades 1-4) and the serum levels of bilirubin, bile acids, and ammonium were measured to assess the efficacy of detoxification. As a measure of liver synthesis function, thromboplastin time and fibrinogen were analyzed. The safety of the procedure was assessed by documenting adverse effects on mean arterial blood pressure, platelet count, and clinical course. Seven out of nine patients were bridged successfully to either native organ recovery (n = 1) or liver transplantation (n = 6), one of them twice. Six out of nine patients undergoing single-pass albumin dialysis (ten treatments) survived. In six patients, hepatic encephalopathy could be reduced at least by one degree. Ammonium, bilirubin, and bile acid levels decreased in all patients. One patient had an allergic reaction to albumin.

CONCLUSIONS

In childhood acute liver failure, treatment with single-pass albumin dialysis was generally well tolerated and seems to be effective in detoxification and in improving blood pressure, thus stabilizing the critical condition of children before liver transplantation and facilitating bridging to liver transplantation. It may be beneficial in avoiding severe neurologic sequelae after acute liver failure and thereby improve survival. Single-pass albumin dialysis is an inexpensive albumin-based detoxification system that is easy to set up and requires little training. Whether and to what extent single-pass albumin dialysis can support children with acute liver failure until native liver recovery remains unclear.

Chilean experience in liver transplantation for acute liver failure in children

BACKGROUND

Acute liver failure (ALF) in children is a life-threatening condition, associated with high mortality, and in almost one third of the cases, with no other therapeutic option than orthotopic liver transplant (OLT). The aim of this study was to present our experience with OLT for ALF in pediatric patients in Chile. Patients fulfilling the criteria for ALF who were transplanted in our centers were prospectively included in an excel Microsoft database. We analyzed demographics, etiology, surgical techniques, complications, and long-term results.

PATIENTS AND METHODS

Between 1994 and 2009, we transplanted 52 pediatric patients with ALF. The most frequent known etiology was acute hepatitis A in 9 cases (18%), but in 26 cases (50%) it was impossible to determine the etiology. Thirty- one patients were males (63%). The overall mean age was 7.5 years and the mean weight, 28.1 kg. Thirty-five (67%) received a cadaveric graft. Among them in 18 cases (34%) the liver had to be reduced but 17 (33%) received whole livers. There were 17 (33%) recipients of living-related livers. Twenty-two patients needed reoperation, including 13 due to surgical complications (59%) and 9 (41%) as planned interventions. Ten patients were retransplanted.

RESULTS

Actuarial survival of patients at 1 year was 80% and at 5 and 10 years, 72%. Graft survival at 1 year was 79%, at 5 years 69%, and at 10 years 50%.

CONCLUSION

We have reported a series of pediatric liver transplant patients due to ALF whose results were comparable to other reported series. Living donor transplantation for ALF should be considered and offers a low morbidity rate without mortality.

Clinical implications of hepatitis A virus ribonucleic acid detection and genotyping in acute liver failure in children in Argentina

OBJECTIVES

To investigate the detection of hepatitis A virus ribonucleic acid in patients with acute liver failure and to assess if the results have any clinical implications for the evolution of acute liver failure in children. Hepatitis A infection, a vaccine-preventable disease, is an important cause of acute liver failure in children in Argentina. Universal vaccination in 1-yr-old children was implemented in June 2005.

DESIGN

Observational study in which patients were divided into Group 1 consisting of positive hepatitis A virus ribonucleic acid and Group 2 consisting of negative hepatitis A virus ribonucleic acid.

SETTING

Pediatric intensive care unit in National Pediatric Hospital "Dr. J. P. Garrahan," Buenos Aires, Argentina.

PATIENTS

Thirty-three patients with the diagnosis of acute liver failure secondary to hepatitis A virus infection and admitted to the Garrahan Pediatric Hospital between September 2003 and September 2005 were enrolled in the study. Twenty of these children were admitted to the pediatric intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Samples for total ribonucleic acid detection and genotyping were obtained from serum and/or stools on admission. We found positive hepatitis A virus ribonucleic acid in 13 patients and negative hepatitis A virus ribonucleic acid in 20 patients. The following clinical variables were evaluated: time of evolution, hospital stay, admission to the pediatric intensive care unit, pediatric intensive care unit stay, time on mechanical ventilation, criteria for orthotopic liver transplantation, and mortality. Characterization of the isolates did not reveal differences related to genotype; all cases were IA. No statistical significance was found as to the variables. However, positive hepatitis A virus ribonucleic acid showed lower percentages of pediatric intensive care unit admissions, criteria for orthotopic liver transplantation, number of orthotopic liver transplantation, and mortality than the group of patients with negative hepatitis A virus ribonucleic acid.

CONCLUSIONS

Hepatitis A virus genotyping studies did not show any particularities, all cases were IA and, thus, apparent associations between genotype and the clinical presentation of acute liver failure could not be found.

Herpes simplex virus sepsis and acute liver failure

Acute liver failure is a life threatening disease mostly triggered by drug-induced or toxic liver damage or viral hepatitis. Herpes Simplex virus (HSV) hepatitis is rare and accounts for only 1% of all acute liver failures. The importance of HSV-induced acute liver failure is based on its extremely severe clinical course with lethality rates of almost 75%. HSV hepatitis is just one of several clinical manifestations of HSV sepsis leading more frequently to encephalitis, pneumonia and esophagitis. Local herpes infection or recurrence of dermal lesions (herpes labialis, herpes genitalis), however, is common and account for the high prevalence of HSV-1 or HSV-2 infection in adults. Another rare entity is visual dissemination, which mostly affects immunocompromised patients. Compromised cellular immunity is a major risk factor for HSV sepsis because of either primary infection or reactivation of occult chronic HSV infection. Delayed diagnosis without antiviral therapy significantly contributes to the unfavorable outcome. Typically, anicteric hepatitis is seen in patients with HSV hepatitis. Because of its low incidence, however, and the lack of dermal manifestations, HSV hepatitis is rarely considered in the context of acute liver failure. In addition, diagnostic tests might not always be available. Therefore, it is a generally accepted consensus to begin antiviral therapy pre-emptively with acyclovir in cases of acute liver failure of unknown origin, in which high urgency (HU) liver transplantation remains the only therapeutical option. Even in the case of early specific therapy, sepsis may prevail and the indication for HU transplantation must be evaluated carefully. The outcome after liver transplantation for HSV-induced liver failure with reported survival rates of more than 40% is good. Because of the risk of recurrence, lifelong prophylaxis with acyclovir is recommended.

Liver transplantation in children with fulminant hepatic failure: The UCL experience

The outcome of pediatric LT for FHF was shown to be poor in our center. To better understand such results, recipient and transplant parameters with a putative impact on post-transplant outcome were analyzed in LT for FHF. Between March 1984 and June 2002, 33 children with FHF received a primary liver allograft. The overall results in this series were studied with respect to pre-operative demographic and metabolic variables, peri-operative events, and outcome. Five-yr patient and graft survivals were 71% and 66%, respectively, with a retransplantation rate at 18%. Incidences of perioperative hemorrhage, of HAT and PVT were 14%, 8%, and 4%, respectively. Five-yr acute rejection-free survival rate was 55%. These data confirm the worse outcome following LT for FHF when compared with LT in elective, non-malignant indications such as BA; results in FHF could not be related to surgical or immunological complications in the post-transplant period and it is hypothesized that the MOF associated with FHF contributes to early post-transplant mortality which would justify special management, including aggressive renal and hepatic support.

Clinicopathologic spectrum of massive and submassive hepatic necrosis in infants and children

Clinicopathologic features of 45 patients with fulminant hepatic failure due to massive or submassive hepatic necrosis were studied. Both percutaneous biopsies and liver explants were available in 23 patients, whole livers only in 11 cases, and biopsies only in 11 cases. An etiologic diagnosis was established in 16 cases (36%). A further 3 cases (7%) were associated with aplastic anemia. Established etiologies included drug reactions (n = 7); autoimmune hepatitis, type 2 (n = 3); halothane hepatitis (n = 1); ischemia/hypotension (n = 1); mushroom poisoning (n = 1); mitochondrial disorder (n = 1); hemophagocytic lymphohistiocytosis (n = 1); and adenoviral hepatitis (n = 1). The extent of necrosis on liver biopsy correlated poorly with that in liver explants (mean difference, 32% +/- 23.8%). Almost all cases could be classified into one of 2 broad patterns of necrosis, namely, (1) zonal coagulative necrosis or (2) panlobular (nonzonal) necrosis. These patterns differed significantly with respect to several clinical parameters including sex ratio, peripheral blood white cell count, serum aspartate transaminase and alanine transaminase, conjugated bilirubin, and alkaline phosphatase levels. Livers with panlobular necrosis showed a spectrum of histopathologic findings that included central venulitis (76%), lymphocytic infiltration of large duct/gallbladder epithelium (54%), and syncytial giant cell transformation (18%). These features were not seen in livers with zonal coagulative necrosis which frequently showed prominent steatosis (91%). Both patterns of necrosis frequently showed ductular proliferation (100%) and cholangiolitis (80%). The diagnostic yield of ancillary studies (histochemistry, immunohistochemistry, and electron microscopy) was very low (<1%). The small proportion of cases with etiologic diagnoses precluded correlation of clinical and histopathological parameters with specific etiologies. In summary, this study describes the spectrum of changes seen in massive and submassive necrosis in children and identifies clinical features that might differentiate between 2 broad patterns of necrosis.

Etiology and prognosis of acute liver failure in children

1. The etiology of acute liver failure in children differs from that in adults, with metabolic conditions being commoner in Europe and North America and hepatitis A being the commonest cause in Asia and South America. 2. Encephalopathy usually is a late feature and is not essential for the diagnosis. 3. Unlike adults, there are no good prognostic criteria that can predict survival without liver transplantation. 4. It is important to exclude genetic multisystem disorders before liver transplantation is considered.

Fulminant hepatic failure in children: etiology, histopathology and MDCT findings

INTRODUCTION

The purpose of this study is to determine the etiologies, histopathology and MDCT findings of children with fulminant hepatic failure admitted to our institution.

MATERIALS AND METHODS

Between June 2004 and November 2006, 15 children with fulminant hepatic failure who underwent MDCT were included retrospectively in this study. Twelve patients had liver biopsies. The patients were divided into three groups as hyperacute (Group I), acute (Group II) and subacute (Group III) depending on onset of hepatic encephalopathy.

RESULTS

Hepatitis A in 4 patients, non-A, non-E hepatitis in 4; mushroom poisoning in 3; fulminant Wilson's disease in 2; autoimmune hepatitis in 1; and both hepatitis B and toxic hepatitis (with leflunomide treatment) in 1 patient were detected. MDCT of all three groups revealed diffuse reduction in hepatic attenuation in 11 patients; ascites in 9; periportal edema in 6; edema of gallbladder wall in 6; splenomegaly in 6; heterogeneous hepatic parenchyma in 6; hepatomegaly in 3; irregular contours of liver in 2; multiple micronodules in 1 and necrotic areas and regeneration in liver parenchyma in 2 patients. Histopathologic evaluation of liver biopsies showed massive hepatic necrosis, inflammatory cell infiltration and ductular proliferation in 8 patients, periportal edema in 6, edema of gallbladder wall in 5, regenerating nodules and fibrous septa consistent with cirrhotic pattern in 2, and regenerating nodules and necrotic areas in 2 patients.

CONCLUSION

The most common MDCT findings in fulminant hepatic failure were diffuse reduction in hepatic attenuation and ascites. Massive hepatic necrosis was the most common histopathologic finding.

Pediatric acute liver failure with molecular adsorbent recirculating system treatment

BACKGROUND

The prognosis of pediatric acute liver failure (PALF) has been significantly improved by emergency orthotopic liver transplantation (OLT). Since 2004, the molecular adsorbent recirculating system (MARS) has been proposed as a bridging procedure. The aim of our study was to assess its efficacy in children with PALF.

PATIENTS AND METHODS

Since 1999 we performed treatment of 39 fulminant hepatic failure (FHF) cases with MARS. Since September 2004 we treated 6 pediatric patients with FHF who were of mean age 10.6 years (range, 3-15 years) including 4 females and 2 males. In 3 cases the cause of FHF was unknown; in 2 cases, it was induced by paracetamol overdose; and in 1, by acute hepatitis B virus. Inclusion criteria were: bilirubin >15 mg/dL; creatinine >or=2 mg/dL; encephalopathy grade >II; and International normalized ratio (INR) >2.5. Other estimated parameters were: AST and ALT serum levels, lactate, and urine volume. Neurological status was monitored using the Glasgow Coma Scale (GCS). Continuous MARS treatment was performed in all patients with a kit change every 8 hours. Intensive care unit (ICU) treatment was applied to optimize regeneration and to prevent cardiovascular complications.

RESULTS

We observed a significant improvement among levels of bilirubin (P< .009), ammonia (P< .005), creatinine (P< .02), GCS (P< .002), and predictive criteria and as Sequential Organ Failure Assessment (SOFA) and Pediatric End-Stage Liver Disease (PELD). Three children underwent OLT: 1 died after 5 days due to primary nonfunction and 2 children are alive after a median follow-up of 14 months. In 2 children the MARS treatment led to resolution of clinical status without liver transplantation. One child died before OLT due to sepsis and multiorgan failure.

CONCLUSIONS

We concluded that application of the MARS liver support device in combination with experienced ICU management contributed to improve the clinical status in children with PALF awaiting liver transplantation.

Evolution in the management of acute liver failure-associated aplastic anaemia in children: a single centre experience

BACKGROUND/AIMS

Bone marrow failure (BMF) is a potentially life-threatening complication of acute liver failure (ALF).

METHODS

To investigate prevalence and evolving management of BMF associated with ALF, we reviewed all cases seen in our centre over 17 years. BMF was classified as: (a) bone marrow hypoplasia, (b) severe aplastic anaemia (SAA) and (c) very severe aplastic anaemia (VSAA), using standard criteria. We compared outcomes in children receiving: (1) medical treatment only with or without immunomodulation (anti-lymphocyte globulin, calcineurin inhibitors, G-CSF); (2) medical treatment with or without immunomodulation plus liver transplantation (LT); (3) haematopoietic stem cell transplantation (HSCT).

RESULTS

Of 213 patients with ALF, 20 [(9.4%); 14 (70%) boys] developed BMF after a median of 1 month (range, 0.5 to 7). Seven had VSAA, 7 SAA and 6 bone marrow hypoplasia. Five children were treated medically, including 3 by immunomodulation; 10 (50%) received LT, with immunomodulation in 6; 5 (25%) received HSCT, in one after LT. Four (20%) children died, only one as consequence of AA. There was no difference in recovery, complication rates or outcome among the three groups.

CONCLUSIONS

Aggressive management of ALF-associated AA, including immunomodulation, HSCT and LT, is successful in most cases. HSCT has the advantage of removing the risk of late clonal disorders.

Safety and efficacy of N-acetylcysteine in children with non-acetaminophen-induced acute liver failure

Acute liver failure (ALF) carries a high mortality in children. N-acetylcysteine (NAC), an antioxidant agent that replenishes mitochondrial and cytosolic glutathione stores, has been used in the treatment of late acetaminophen-induced ALF and non-acetaminophen-induced ALF. In our unit, NAC was introduced as additional treatment for non-acetaminophen-induced ALF in 1995. The aim of this study was to evaluate the safety and efficacy of NAC in children with ALF not caused by acetaminophen poisoning. A retrospective review of medical records of 170 children presenting with nonacetaminophen-induced ALF between 1989 and 2004 was undertaken. ALF was defined as either international normalized ratio of prothrombin time (INR) > 2 and abnormal liver function or INR >1.5 with encephalopathy and abnormal liver function. Children were divided into the following groups: Group 1 (1989-1994), standard care (n = 59; 34 [58%] male; median age 2.03 yr, range 0.003-15.8 yr); and Group 2 (1995-2004), standard care and NAC administration (n = 111; 57 [51%] male; median age 3.51 yr, range 0.005-17.4 yr). NAC was administered as a continuous infusion (100 mg/kg/24 hours) until INR < 1.4, death, or liver transplantation (LT). The median duration of NAC administration in Group 2 was 5 (range, 1-77) days. Complications were noted in 8 (10.8%) children: rash in 3, arrhythmia in 3, and dizziness and peripheral edema in 1. One child had an allergic reaction (bronchospasm) and NAC was stopped. A total of 41 (71%) children in Group 1 vs. 85 (77%) in Group 2 required admission to intensive care, P = not significant (ns). The length of intensive care stay was 6 (range, 1-58) days in Group 1 vs. 5 (range, 1-68) days in Group 2, P = ns and length of hospital stay was 25 (range, 1-264) days vs. 19 (range, 1-201) days, P = 0.05. The 10-yr actuarial survival was 50% in Group 1 compared to 75% in Group 2, P = 0.009. Survival with native liver occurred in 13 (22%) in Group 1 vs. 48 (43%) in Group 2, P = 0.005; 15 (25%) in Group 1 died without transplant vs. 21 (19%) in Group 2, P = ns; and LT was performed in 32 (54%) vs. 42 (38%), P = ns. Death after transplantation occurred in 15 (39%) in Group 1 vs. 8 (16%) in Group 2, P = 0.02. In conclusion, NAC is safe in non-acetaminophen-induced ALF. In this retrospective study NAC was associated with a shorter length of hospital stay, higher incidence of native liver recovery without transplantation, and better survival after transplantation.

Hepatitis A as an etiologic agent of acute liver failure in Latin America

BACKGROUND

This prospective, multicenter study examined the importance of hepatitis viruses as etiological agents of acute liver failure (ALF) and the outcome of ALF cases in Latin American children and adolescents.

METHODS

The study was conducted for minimum 12 months in 9 centers in Argentina, Brazil, Chile, Colombia, Costa Rica, and Mexico during 2001-2002. Hospitalized patients aged 1-20 years with a suspected diagnosis of ALF were included in the study and tested for serologic markers for hepatitis A, B, and C viruses.

RESULTS

Of the 106 patients enrolled, 88 were included in the analysis. Median age was 5 years, and 55% with ALF were aged 1-5 years. A total of 37 individuals (43%) tested positive for anti-hepatitis A virus (HAV) immunoglobulin M (IgM) as marker of acute HAV infection; one was positive for anti-hepatitis B core antigen IgM and negative for hepatitis B surface antigen. None had markers of hepatitis C virus infection. Mortality rates in the overall study cohort (45%) and for those who tested anti-HAV IgM positive (41%) were similar. Forty-one percent of all patients and 46% of those positive for anti-HAV IgM underwent transplantation. The mortality rate in those with liver transplantation was half of that in patients who were not transplanted (28% versus 57%).

CONCLUSIONS

HAV was the main etiologic agent of ALF in the population studied.

Comparison of the applicability of two prognostic scoring systems in patients with fulminant hepatic failure

BACKGROUND

Distinguishing those patients with fulminant hepatic failure (FHF) and who require transplantation from those FHF patients who will survive with receiving only intensive medical care remains problematic, and this distinction is important because of the chronic shortage of donor livers.

METHODS

To assess the applicability of two prognostic scoring systems, referred to as the London and Clichy criteria, we compared using both systems, at the time of admission, for 43 FHF patients (15 M/28 F; age: 3716 yrs). Acetaminophen (ACM) was the etiology for 16 patients, while the remaining 27 had other etiologies. All the patients received intensive care, and 18 (8 ACM/10 non-ACM) had investigational BAL support.

RESULTS

For the ACM toxicity, neither the London nor the Clichy criteria exhibited acceptable sensitivity (71 vs 86%, respectively), specificity (78 vs 56%, respectively), a positive predictive value (71 vs 60%, respectively), a negative predictive value (78 vs 83%, respectively) or predictive accuracy (75 vs 69%, respectively) to predict patient survival without transplantation. In contrast, applying the London and Clichy criteria to the FHF patients with non-ACM etiologies showed a sensitivity of 96 vs 80%, respectively, a specificity of 100 vs 100%, respectively, a positive predictive value of 100 vs 100%, respectively a negative predictive value of 67 vs 29%, respectively and a predictive accuracy of 96% vs 82%, respectively.

CONCLUSIONS

Overall, the London criteria more accurately predicted the need for transplantation, and neither the London criteria nor the Clichy prognostic criteria accurately predicted the outcome of those patients who suffered with FHF due to ACM. BAL support may have contributed to the survival of the patients with ACM toxicity and who didn't undergo transplantation, and this survival exceeded the predictions of both prognostic systems. Additional multicenter studies should be conducted to refine these prognostic scoring systems, and this will help physicians rapidly identify those FHF patients who can survive without undergoing liver transplantation.

Acute liver failure in children

OBJECTIVE

To review the incidence, etiologies, pathophysiology, and treatment of acute liver failure (ALF) in children. Emphasis will be placed on the initial management of the multiple organ system involvement of ALF.

METHOD

MEDLINE search from 1970 to March 2005 was performed. Search headings were as follows: acute liver failure, fulminant liver failure, pediatric liver failure, hepatic encephalopathy, and liver transplantation. Studies written in English were selected. Pediatric studies were emphasized. Adult studies were referenced if there were no pediatric studies available in regard to a specific aspect of liver failure.

CONCLUSIONS

Pediatric acute liver failure is a rare but life-threatening disease. The common etiologies differ for given age groups. Management includes treating specific causes and supporting multiple organ system failure. Commonly associated disorders that require initial recognition and treatment include energy production deficiencies (hypoglycemia), coagulation abnormalities, immune system dysfunctions, encephalopathy, and cerebral edema. Criteria used to determine the need for liver transplant are reviewed as well as the difficulties associated with predicting which patients will meet these criteria and how rapidly liver transplant will become the only option. Finally, experimental procedures that may provide additional time for the liver to recover are briefly reported.

Brain edema and intracranial hypertension in fulminant hepatic failure: Pathophysiology and management

Intracranial hypertension is a major cause of morbidity and mortality of patients suffering from fulminant hepatic failure. The etiology of this intracranial hypertension is not fully determined, and is probably multifactorial, combining a cytotoxic brain edema due to the astrocytic accumulation of glutamine, and an increase in cerebral blood volume and cerebral blood flow, in part due to inflammation, to glutamine and to toxic products of the diseased liver. Validated methods to control intracranial hypertension in fulminant hepatic failure patients mainly include mannitol, hypertonic saline, indomethacin, thiopental, and hyperventilation. However all these measures are often not sufficient in absence of liver transplantation, the only curative treatment of intracranial hypertension in fulminant hepatic failure to date. Induced moderate hypothermia seems very promising in this setting, but has to be validated by a controlled, randomized study. Artificial liver support systems have been under investigation for many decades. The bioartificial liver, based on both detoxification and swine liver cells, has shown some efficacy on reduction of intracranial pressure but did not show survival benefit in a controlled, randomized study. The Molecular Adsorbents Recirculating System has shown some efficacy in decreasing intracranial pressure in an animal model of liver failure, but has still to be evaluated in a phase III trial.

New management options for end-stage chronic liver disease and acute liver failure: potential for pediatric patients

The management of children with end-stage chronic liver disease and acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but studies and publications have mainly concerned adult patients. Therapeutic approaches to complications of end-stage chronic liver disease and acute liver failure (e.g. refractory ascites, hepatorenal syndrome, encephalopathy, and cerebral edema) that may be applied to children are reviewed in this article.Mild-to-moderate ascites should be managed by modest salt restriction and oral diuretic therapy in the first instance. Large volume paracentesis associated with colloid volume expansion and diuretic therapy may be effective for acute relief. Treatment of hepatorenal syndrome type 1 with vasopressin analogs (terlipressin) is recommended prior to liver transplantation in order to improve renal function. Prevention and treatment of chronic hepatic encephalopathy are directed primarily at controlling the events that may precipitate hepatic encephalopathy and at reducing ammonia generation and increasing its detoxification or removal. In addition to reduction of gut ammonia production using non-absorbable disaccharides such as lactulose and/or antibacterials such as neomycin, sodium benzoate may be used on a long-term basis to prevent, stabilize, or improve hepatic encephalopathy. The management of hepatic encephalopathy in acute liver failure is considerably more unsatisfactory; treatment is aimed at preventing brain edema and intracranial hypertension. Extracorporeal liver support devices are now used commonly in critically ill children with acute renal failure, advanced hepatic encephalopathy, cerebral edema, intracranial hypertension, and severe coagulopathy. Continuous renal replacement therapy could potentially help support patients until liver transplantation is performed or liver regeneration occurs. The Molecular Adsorbent Recirculating System (MARS or albumin dialysis) is the liver support system most frequently used worldwide in adults and appears to offer distinct advantages over hepatocyte-based systems. There are no specific medical therapies or devices that can correct all of the functions of the liver. Apart from a few metabolic diseases presenting with severe liver dysfunction for which specific medical therapies may preclude the need for liver transplantation, liver transplantation still remains the only definitive therapy in most instances of end-stage chronic liver disease and acute liver failure. Future research should focus on gaining a better understanding of the mechanisms responsible for liver cell death and liver regeneration, as well as developments in hepatocyte transplantation and liver-directed gene therapy.

Cryptogenic fulminant hepatic failure in infancy: report of 2 cases with unique vascular obstructive changes in native livers

Although the causes of fulminant hepatic failure (FHF) remain cryptogenic in many cases, a few reports have reviewed the pathological findings of native livers to evaluate the etiology. We report 2 cases of infantile cryptogenic FHF with unique vascular obstructive changes in the native livers. Clinically, it was notable that these 2 patients developed FHF very early in life, at 2 months and 5 months of age, respectively. One patient died from chronic rejection associated with hepatic veno-occlusive disease 4 months after transplantation. Histologically, hepatocytes in the native livers were completely destroyed in both patients, and vascular findings revealed obstruction of central veins in 1 patient and obstruction of portal veins in the other patient. Although the pathogenesis of vascular obstructions is not yet understood, this study suggests that an obstructive vascular event may be a contributing etiologic factor of FHF in infancy.