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

Definitions, etiopathogenesis and epidemiology of ALF

Acute liver failure (ALF) is a rare but preventable cause of acute hepatic dysfunction which is associated with significant mortality, unless treated appropriately. There are significant regional variations in the etiologies of ALF globally and this determines the outcomes of the disease as well as the long-term survival in patients receiving liver transplantation for management. Improvements in understanding of disease pathophysiology and critical care medicine have led to better outcomes over the last few decades. Despite this, the burden of indeterminate ALF and the pathogenesis of many etiological agents are yet to be fully known. Improvements in diagnostic and prognostic modalities are expected to decrease the morbidity and mortality associated with ALF. Changes in vaccination programs and stronger legislative practices regarding over-the-counter sale of acetaminophen and non-proprietary drugs are expected to reduce the burden of disease globally.

Paediatric acute liver failure: a multidisciplinary perspective on when a critically ill child is unsuitable for liver transplantation

Paediatric acute liver failure is a devastating condition with high morbidity and mortality, which is challenging to manage for the hepatologist, intensivist, and associated specialists. Emergency liver transplantation is required for 10-20% of patients, but for 10% of critically ill children, liver transplantation is deemed unsuitable; the child might be too unwell, or the underlying cause might carry a poor prognosis. Other social, logistical, or ethical considerations are often relevant. Liver transplantation when a patient is too unwell creates perioperative risk to the child that could lead to morbidity, mortality, and potential graft wastage, which is detrimental for others on the waiting list. Donor liver scarcity should prompt an evaluation of whether a transplant is justified through a holistic multidisciplinary lens that considers medical, social, logistical, and ethical concerns. In this Review, we explore, from a multidisciplinary perspective, why a critically unwell child with paediatric acute liver failure might be unsuitable for liver transplantation.

Diagnosis and management of pediatric acute liver failure: consensus recommendations of the Indian Society of Pediatric Gastroenterology, Hepatology, and Nutrition (ISPGHAN)

Timely diagnosis and management of pediatric acute liver failure (PALF) is of paramount importance to improve survival. The Indian Society of Pediatric Gastroenterology, Hepatology, and Nutrition invited national and international experts to identify and review important management and research questions. These covered the definition, age appropriate stepwise workup for the etiology, non-invasive diagnosis and management of cerebral edema, prognostic scores, criteria for listing for liver transplantation (LT) and bridging therapies in PALF. Statements and recommendations based on evidences assessed using the modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) system were developed, deliberated and critically reappraised by circulation. The final consensus recommendations along with relevant published background information are presented here. We expect that these recommendations would be followed by the pediatric and adult medical fraternity to improve the outcomes of PALF patients.

Current Status and Outcomes of Living Donor Liver Transplantation for Pediatric Acute Liver Failure: Results From a Multicenter Retrospective Study Over Two Decades

BACKGROUND

Although the outcomes of living donor liver transplantation (LDLT) for pediatric acute liver failure (PALF) have improved, patient survival remains lower than in patients with chronic liver disease. We investigated whether the poor outcomes of LDLT for PALF persisted in the contemporary transplant era.

METHODS

We analyzed 193 patients who underwent LDLT between December 2000 and December 2020. The outcomes of patients managed in 2000-2010 (era 1) and 2011-2020 (era 2) were compared.

RESULTS

The median age at the time of LDLT was 1.2 years both eras. An unknown etiology was the major cause in both groups. Patients in era 1 were more likely to have surgical complications, including hepatic artery and biliary complications (p = 0.001 and p = 0.013, respectively). The era had no impact on the infection rate after LDLT (cytomegalovirus, Epstein-Barr virus, and sepsis). The mortality rates of patients and grafts in era one were significantly higher (p = 0.03 and p = 0.047, respectively). The 1- and 5-year survival rates were 76.4% and 70.9%, respectively, in era 1, while they were 88.3% and 81.9% in era 2 (p = 0.042). Rejection was the most common cause of graft loss in both groups. In the multivariate analysis, sepsis during the 30 days after LDLT was independently associated with graft loss (p = 0.002).

CONCLUSIONS

The survival of patients with PALF has improved in the contemporary transplant era. The early detection and proper management of rejection in patients, while being cautious of sepsis, should be recommended to improve outcomes further.

Prognostic Markers in Pediatric Acute Liver Failure

Introduction

Acute liver failure (ALF), although rare in children, is a complex progressive pathology, with multisystem involvement and high mortality. Isolated variables or those included in prognostic scores have been studied, to optimize organ allocation. However, its validation is challenging. This study aimed to assess the accuracy of several biomarkers and scores as predictors of prognosis in pediatric ALF (PALF).

Methods

An observational study with retrospective data collection, including all cases of ALF, was defined according to the criteria of the Pediatric Acute Liver Failure Study Group, admitted to a pediatric intensive care unit (PICU) for 28 years. Two groups were defined: spontaneous recovery (SR) and non-SR (NSR) - submitted to liver transplantation (LT) or death at PICU discharge.

Results

Fifty-nine patients were included, with a median age of 24 months, and 54% were female. The most frequent etiologies were metabolic (25.4%) and infectious (18.6%); 32.2% were undetermined. SR occurred in 21 patients (35.6%). In NSR group (N = 38, 64.4%), 25 required LT (42.4%) and 19 died (32.2%), 6 (15.7%) of whom after LT. The accuracy to predict NSR was acceptable for lactate at admission (AUC 0.72; 95% CI: 0.57-0.86; p = 0.006), ammonia peak (AUC 0.72; 95% CI: 0.58-0.86; p = 0.006), and INR peak (AUC 0.70; 95% CI: 0.56-0.85; p = 0.01). The cut-off value for lactate at admission was 1.95 mmol/L (sensitivity 78.4% and specificity 61.9%), ammonia peak was 64 μmol/L (sensitivity 100% and specificity 38.1%), and INR peak was 4.8 (sensitivity 61.1% and specificity 76.2%). Lactate on admission was shown to be an independent predictor of NSR on logistic regression model. Two prognostic scores had acceptable discrimination for NSR, LIU (AUC 0.73; 95% CI: 0.59-0.87; p = 0.004) and PRISM (AUC 0.71; 95% CI: 0.56-0.86; p = 0.03). In our study, the PALF delta score (PALF-ds) had lower discrimination capacity (AUC 0.63; 95% CI: 0.47-0.78; p = 0.11).

Conclusions

The lactate at admission, an easily obtained parameter, had a similar capacity than the more complex scores, LIU and PRISM, to predict NSR. The prognostic value in our population of the promising dynamic score, PALF-ds, was lower than expected.

Pediatric acute liver failure: Current perspective in etiology and management

Pediatric acute liver failure (PALF) is a catastrophic clinical condition with very high morbidity and mortality without early detection and intervention. It is characterized by the acute onset of massive hepatocellular injury that releases circulating inflammatory mediators, resulting in metabolic disturbances, coagulopathy, hepatic encephalopathy and multi-organ failure. The etiological spectrum is dominated by hepatotropic viruses, drug-induced liver injury, metabolic and genetic disorders and immune-mediated diseases. Unlike adults, indeterminate causes for acute liver failure constitute a considerable proportion of cases of acute liver failure in children in the west. The heterogeneity of age and etiology in PALF has led to difficulties in developing prognostic scoring. The recent guidelines emphasize prompt identification of PALF, age-appropriate evaluation for hepatic encephalopathy and laboratory evaluation with careful monitoring. Current therapy focuses on supporting the failing liver and other organs, pending either spontaneous recovery or liver transplantation. Targeted therapy is available for a select group of etiologies. Liver transplantation can be lifesaving and a plan for the same should be organized, whenever indicated. The aim of this review is to define PALF, understand its etiopathogenesis, address the challenges encountered during the management and update the latest advances in liver transplantation and non-transplant treatment options in PALF.

CHALF Score: A Novel Tool to Rapidly Risk Stratify Children in Need of Liver Transplant Evaluation During Acute Liver Failure

BACKGROUND

Pediatric acute liver failure (PALF) can require emergent liver transplantation (LT, >25%) or lead to death (~15%). Existing models cannot predict clinical trajectory or survival with native liver (SNL). We aimed to create a predictive model for PALF clinical outcomes based on admission variables.

METHODS

A retrospective, single-center PALF cohort (April 2003 to January 2022) was identified using International Classification of Disease codes, selected using National Institutes of Health PALF Study Group (PALFSG) criteria, and grouped by clinical outcome (SNL, LT, or death). Significant admission variables were advanced for feature selection using least absolute shrinkage and selection operator regression with bootstrapping (5000×). A predictive model of SNL versus LT or death was created using logistic regression and validated using PALFSG data.

RESULTS

Our single-center cohort included 147 patients (58% SNL, 32% LT, 10% expired), while the PALFSG validation cohort included 492 patients (50% SNL, 35% LT, 15% expired). Admission variables associated with SNL included albumin (odds ratio [OR], 16; P < 0.01), ammonia (OR, 2.37; P < 0.01), and total bilirubin (OR, 2.25; P < 0.001). A model using these variables predicted SNL versus LT or death with high accuracy (accuracy [0.75 training, 0.70 validation], area under the curve [0.83 training, 0.78 validation]). A scaled score (CHLA-acute liver failure score) was created that predicted SNL versus LT or death with greater accuracy (C statistic 0.83) than Pediatric End-Stage Liver Disease (C statistic 0.76) and admission liver injury unit (C statistic 0.76) scores.

CONCLUSIONS

The CHLA-acute liver failure score predicts SNL versus LT or mortality in PALF using admission laboratories with high accuracy. This novel, externally validated model offers an objective guide for urgent referral to a pediatric LT center.

Prognostic markers in hepatitis A-related pediatric acute liver failure and validation of the Peds-hepatitis A virus prognostic model

OBJECTIVES

Hepatitis A virus (HAV) is the commonest cause for pediatric acute liver failure (PALF) in India. The objective of the study was to identify the predictors of mortality and to evaluate the utility of Peds-HAV model in a cohort of non-LT HAV-PALF.

METHODS

The study included HAV-related PALF from two non-transplant centers. The predictors of outcome were identified by univariate analysis followed by Cox regression analysis. The prognostic accuracy of Peds-HAV model, King's College Hospital (KCH) criteria and pediatric end-stage liver disease score (PELD) were evaluated.

RESULTS

As many as 140 children with PALF were included, of whom 96 (68.6%) children had HAV-PALF. On Cox regression analysis, international normalized ratio (INR) (p < 0.001), jaundice to encephalopathy (JE) interval (p < 0.001) and hepatic encephalopathy (HE) grade 3/4 (p = 0.01) were independent predictors of mortality. The mortality rates were 0% (0/42), 14.3% (3/21), 60% (9/15) and 94.4% (17/18) when none, 1, 2 or 3 criteria of the Peds-HAV were met, respectively. Peds-HAV model at a listing cut-off of  ≥ 2 criteria predicted death with 89.7% sensitivity and 89.6% specificity. In contrast, KCH criteria had a lower sensitivity of 62.1%. PELD score had a sensitivity of 89.7% and specificity of 85.1% at a cut-off of 30. The overall prognostic accuracy of Peds-HAV model (89.6%) was higher than those of KCH (83.3%) and PELD (86.5%).

CONCLUSION

INR, HE grade and JE interval were independent predictors of mortality. The study provides an external validation of Peds-HAV model as a prognostic score in HAV-PALF.

CLINICAL TRIAL REGISTRY NUMBER

Not applicable as this is a retrospective study.

Age and Sex in the Development of Hepatic Encephalopathy: Role of Alcohol

Hepatic encephalopathy (HE) is a neurological condition linked to liver failure. Acute HE (Type A) occurs with acute liver failure, while chronic HE (Type C) is tied to cirrhosis and portal hypertension. HE treatments lag due to gaps in understanding its development by gender and age. We studied how sex and age impact HE and its severity with combined liver toxins. Our findings indicate that drug-induced (thioacetamide, TAA) brain edema was more severe in aged males than in young males or young/aged female rats. However, adding alcohol (ethanol, EtOH) worsens TAA's brain edema in both young and aged females, with females experiencing a more severe effect than males. These patterns also apply to Type A HE induced by azoxymethane (AZO) in mice. Similarly, TAA-induced behavioral deficits in Type C HE were milder in young and aged females than in males. Conversely, EtOH and TAA in young/aged males led to severe brain edema and fatality without noticeable behavioral changes. TAA metabolism was slower in aged males than in young or middle-aged rats. When TAA-treated aged male rats received EtOH, there was a slow and sustained plasma level of thioacetamide sulfoxide (TASO). This suggests that with EtOH, TAA-induced HE is more severe in aged males. TAA metabolism was similar in young, middle-aged, and aged female rats. However, with EtOH, young and aged females experience more severe drug-induced HE as compared to middle-aged adult rats. These findings strongly suggest that gender and age play a role in the severity of HE development and that the presence of one or more liver toxins may aggravate the severity of the disease progression.

Improved mortality prediction for pediatric acute liver failure using dynamic prediction strategy

OBJECTIVES

To develop and validate a prediction tool for pediatric acute liver failure (PALF) mortality risks that captures the rapid and heterogeneous clinical course for accurate and updated prediction.

METHODS

Data included 1144 participants with PALF enrolled during three phases of the PALF registry study over 15 years. Using joint modeling, we built a dynamic prediction tool for mortality by combining longitudinal trajectories of multiple laboratory and clinical variables. The predictive performance for 7-day and 21-day mortality was assessed using the area under curve (AUC) through cross-validation and split-by-time validation.

RESULTS

We constructed a prognostic joint model that combines the temporal trajectories of international normalized ratio, total bilirubin, hepatic encephalopathy, platelet count, and serum creatinine. Dynamic prediction using updated information improved predictive performance over static prediction using the information at enrollment (Day 0) only. In cross-validation, AUC increased from 0.784 to 0.887 when measurements obtained between Days 1 and 2 were incorporated. AUC remained similar when we used the earlier subset of the sample for training and the later subset for testing.

CONCLUSIONS

Serial measurements of five variables in the first few days of PALF capture the dynamic clinical course of the disease and improve risk prediction for mortality. Continuous disease monitoring and updating risk prognosis are beneficial for timely and judicious medical decisions.

Live donor liver transplantation for pediatric acute liver failure: challenges and outcomes

OBJECTIVE

This study aimed at studying the challenges and outcomes of live-donor liver transplantation (LDLT) for pediatric acute liver failure (PALF).

STUDY DESIGN

A total of 315 patients with PALF were treated over a period of 11 years. 42 underwent LT (41 LDLT and one DDLT), constituting 38% (41/110) of all pediatric transplants during this duration. The outcomes of LDLT for PALF were analyzed.

RESULTS

All the 41 children who underwent LT met the Kings College criteria (KCC). The etiology was indeterminate in 46.3% (n = 19) children. 75.6% (n = 31) were on mechanical ventilation for grade 3/4 hepatic encephalopathy. There was presence of cerebral edema on a computed tomography scan of the brain in 50% of the children. One-third of our children required hemodynamic support with vasopressors. Systemic inflammatory response syndrome and sepsis were observed in 46.3% and 41.4% of patients, respectively. Post-LDLT 1- and 5-yr patient and graft survival were 75.6% and 70.9%, respectively. The survival in children satisfying KCC but did not undergo LT was 24% (38/161). Vascular and biliary complication rates were 2.4% and 4.8%, respectively. No graft loss occurred because of acute rejection. In multivariate analysis, pre-LT culture positivity and cerebral edema, persistence of brain edema after transplantation, and resultant pulmonary complications were significantly associated with post-LT death. Thirteen (32%) children who underwent plasmapheresis prior to LT had better post-LT neurological recovery, as evidenced by early extubation.

CONCLUSION

LDLT for PALF is lifesaving and provides a unique opportunity to time transplantation. Good long-term survival can be achieved, despite the majority of patients presenting late for transplantation. Early referral and better selection can save more lives through timely transplantation.

Pediatric acute liver failure in Saudi Arabia: prognostic indicators, outcomes and the role of genetic testing

OBJECTIVE

The objective of this study was to determine the etiologies, outcomes, prognostic indicators and the role of genetic testing in children with acute liver failure (ALF).

METHODS

This retrospective study included 46 patients with pediatric acute liver failure (PALF) according to the PALF study group definition, admitted to King Fahad Specialist Hospital-Dammam, Saudi Arabia, between January 2014 and December 2021. Patients who survived with supportive therapy were designated as the recovery group, whereas those who died or underwent liver transplantation were designated as the death/transplant group.

RESULTS

There were 26 (56.5%) patients in the recovery group and 20 (43.5%) patients in the death/transplant group. Four patients (8.7%) underwent liver transplantation. After indeterminate causes (45.6%), genetic-metabolic diseases and drug-induced liver injury (DILI) were the most common cause with 15.2 and 13%, respectively. Genetic testing had a high yield of (6/31) in identifying monogenic disease associated with ALF. Younger age, lower Glasgow Coma Scale and higher international normalized ratio (INR) on admission were predictors for poor prognosis. The death/transplant group had longer intensive care unit stay ( P  < 0.001), and on admission they had more advanced hepatic encephalopathy ( P  < 0.005), more prolonged prothrombin time ( P  < 0.001), higher lactate ( P  < 0.006), higher total and direct bilirubin ( P  < 0.008) and ( P  < 0.001), respectively.

CONCLUSION

Genetic, metabolic and DILI causes constituted the most common cause of PALF after indeterminate causes. The use of genetic testing can improve diagnostic rates in special cases, but we could not assess the effect of genetic testing on prognosis. The overall survival rate in our study was 65.2%. Younger age, higher admission INR and lower Glasgow coma scale were indicators of poor prognosis.

Pediatric acute liver failure: Reexamining key clinical features, current management, and research prospects

This review aims to synthesize the most updated research, outcomes, and trends in the field of pediatric liver transplantation (LT), specifically focusing on children who have suffered from acute liver failure. Pediatric acute liver failure is a dynamic, life-threatening condition that can either self-resolve or lead to death. LT is a lifesaving intervention. With the introduction of technical variant grafts and recent immunosuppression modifications, overall patient survival, graft survival, and waitlist mortality have improved. Furthermore, recent advances in the knowledge of immunologic mediators of acute liver failure offer the possibility of more detailed understanding of the pathophysiology and new areas for research. Given the success of living donor LT for pediatric patients with acute liver failure, this option should continue to be actively considered as an alternative treatment option for patients who are listed for transplantation and are managed at a multidisciplinary tertiary care transplant center.

Demographics, aetiology and outcome of paediatric acute liver failure in Singapore

Introduction

The aetiology of paediatric acute liver failure (PALF) varies widely according to age, and geographic and socioeconomic factors. This study aimed to examine the epidemiology, aetiology and outcome of PALF in Singapore at a single centre.

Methods

A retrospective review was performed of patients aged 0-18 years who were diagnosed with PALF from 2007 to 2019. PALF was defined by: absence of chronic liver disease; biochemical evidence of acute liver injury; and coagulopathy, non-correctible by vitamin K, defined as prothrombin time (PT) ≥20 seconds or international normalised ratio (INR) ≥2.0 regardless of hepatic encephalopathy (HE) or PT ≥15 seconds or INR ≥1.5 in the presence of HE.

Results

34 patients were included. Median age at diagnosis was 10 months (range 7 days to 156 months). The top three causes of PALF were indeterminate (41.2%), metabolic (26.5%) and infectious (26.5%) aetiologies. A metabolic disorder was the most frequent aetiology in infants <12 months (38.9%), whereas an indeterminate cause was the most common in children >12 months (50%). No cases of viral hepatitis A or B presenting with PALF were detected. Overall spontaneous recovery rate (survival without liver transplantation [LT]) was 38.2%, and overall mortality rate was 47.1%. Six patients underwent living-donor LT, and the post-transplant survival at one year was 83.3%.

Conclusion

The aetiologic spectrum of PALF in Singapore is similar to that in developed Western countries, with indeterminate aetiology accounting for the majority. PALF is associated with poor overall survival; hence, timely LT for suitable candidates is critical to improve survival outcomes.

Etiology, outcome and prognostic indicators of acute liver failure in Asian children

OBJECTIVE

Outcome of pediatric acute liver failure (PALF) in countries with limited availability of LT is not well described. We evaluated the outcome and prognostic indicators of PALF in Malaysia where emergency LT for ALF is limited.

METHODS

In this retrospective review on children < 18 years with PALF, we compared clinical and laboratory parameters between survival after supportive treatment and after LT or succumbed without LT. The predictive values of Liver Injury Unit (LIU; peak laboratory values for international normalized ratio [INR], ammonia, total bilirubin) and upon admission (aLIU) on outcome of PALF was evaluated using receiver operator characteristic (ROC) curves.

RESULTS

Of 77 children (39 males [51%]; median age 2.8 years) with PALF, the overall survival was 55% (n = 42); 52% (n = 40) survived with supportive management, 2.6% (n = 2) after LT. As compared to children who survived without LT, children who had LT/died had lower hemoglobin, aspartate transferase, γ-glutamyl transpeptidase (GGT), and higher serum bilirubin, alkaline phosphatase, ammonia, and serum sodium (p < 0.05). On multivariate analysis, significant independent predictor for death or LT were peak bilirubin > 452 μmol/L and peak GGT < 96 IU/L. The C-index of LIU and aLIU score were 0.79 and 0.68, respectively, indicating that LIU score was a good model in predicting outcome of PALF.

CONCLUSIONS

Overall survival of PALF remained poor. High peak bilirubin and low GGT predict poor outcome of PALF. LIU score is a good model in predicting outcome of PALF and maybe useful in selecting children for emergency LT.

Prognostic factors and scoring systems associated with outcome in pediatric acute liver failure

BACKGROUND

Pediatric acute liver failure (PALF) is an uncommon, devastating illness with significant mortality. Liver transplantation remains the mainstay of treatment for irreversible PALF. The purpose of this study was to determine the etiology and prognostic factors associated with outcome of PALF in South Africa and to evaluate prognostic scoring systems used.

METHODS

Records of 45 pediatric patients younger than 16 years of age who presented with PALF from 1 January 2015 till 31 October 2020 were analysed. Patients were divided into two groups with one group consisting of patients with spontaneous recovery of the liver with supportive treatment (6/45:13.3%) and the second group consisting of patients with poor outcomes who demised (19/45: 42%) or underwent liver transplantation (20/45: 44%).

RESULTS

The median age of presentation was 3.3 years (IQR 1.8-6.9) with the 1-5 years age group constituting majority of patients (55.6%). Median time to follow up was 6.1 months (IQR 0.2-28.8). Higher liver injury unit scores were observed in patients who had poorer outcomes (P = 0.008) with a threshold of greater than 246 having a sensitivity of 84% and specificity of 83% (P < 0.001). Higher peak PELD/MELD (P = 0.006) and admission UKELD (P = 0.002) scores, were found in patients with poorer outcomes. Kings College Hospital criteria (KCHC) was useful in predicting which patients would die without liver transplantation (P = 0.002). Liver transplantation was performed in 20/45 (44%) patients with a post transplantation 1 year patient and graft survival of 80%.

CONCLUSION

Although, survival of PALF patients was lower than high and other low-middle income countries, outcomes post transplantation were good. Our study demonstrates the utility of dynamic scoring systems in PALF patients, it underscores the need for early referral and clinical monitoring in a tertiary center once the criteria for PALF have been met.

The successful application of hemoadsorption for extracorporeal liver support in a child with acute liver failure

A 6-year-old boy developed acute liver failure with hepatic coma due to drug rash with eosinophilia and systemic symptoms (DRESS) after multiple antibiotics exposure. He had hyperbilirubinemia, elevated serum bile acids and hyperammonemia with peak serum levels of total bilirubin, direct bilirubin, bile acids and ammonia measuring 418, 328, 174, and 172 μmol/L respectively. In addition to the use of systemic steroid and other supportive therapy, he also received three sessions of hemoadsorption using the Cytosorb^® column incorporated into the continuous renal replacement therapy circuit as extracorporeal liver support for a total duration of 75 h, which brought down his serum levels of total bilirubin to 119 μmol/L, bile acids to 58 μmol/L, and ammonia to 55 μmol/L. His conscious level gradually regained coupling an improvement of liver function. Except for mild thrombocytopenia and electrolyte disturbances, the therapy was well tolerated with no major complication encountered. Our case demonstrated that hemoadsorption can be safely employed as an adjunctive extracorporeal liver support modality in children with acute liver failure. The potential role and technical concerns of applying such technique in pediatric patients requires further evaluation in future studies.

Therapeutic plasma exchange in children with acute liver failure (ALF): is it time for incorporation into the ALF armamentarium?

Paediatric acute liver failure (PALF) is a rare but devastating condition with high mortality. An exaggerated inflammatory response is now recognised as pivotal in the pathogenesis and prognosis of ALF, with cytokine spill from the liver to systemic circulation implicated in development of multi-organ failure associated with ALF. With advances in medical management, especially critical care, there is an increasing trend towards spontaneous liver regeneration, averting the need for emergency liver transplantation or providing stability to the patient awaiting a graft. Hence, research is ongoing for therapies, including extracorporeal liver support devices, that can bridge patients to transplant or spontaneous liver recovery. Considering the immune-related pathogenesis and inflammatory phenotype of ALF, plasma exchange serves as an ideal liver assist device as it performs both the excretory and synthetic functions of the liver and, in addition, works as an immunomodulatory therapy by suppressing the early innate immune response in ALF. After a recent randomised controlled trial in adults demonstrated a beneficial effect of high-volume plasma exchange on clinical outcomes, this therapy was incorporated in European Association for the Study of Liver (EASL) recommendations for managing adult patients with ALF, but no guidelines exist for PALF. In this review, we discuss rationale, timing, practicalities, and existing evidence regarding the use of plasma exchange as an immunomodulatory treatment in PALF. We discuss controversies in delivery of this therapy as an extracorporeal device, and practicalities of use of plasma exchange as a 'hybrid' therapy alongside other extracorporeal liver assist devices, before finally reviewing outstanding research questions for the future.

Transcranial Doppler Ultrasonography in Children With Acute Liver Failure and Severe Hepatic Encephalopathy

OBJECTIVES

To report our single-center use of transcranial Doppler (TCD) for noninvasive neuromonitoring in pediatric patients with acute liver failure (ALF).

DESIGN

Retrospective cohort from January 2016 to June 2019.

SETTING

PICU in Bicêtre Hospital, Assistance Publique- Hôpitaux de Paris (AP-HP), a national referral center for pediatric liver transplantation.

PATIENTS

Pediatric patients with severe ALF (prothrombin time < 30% and Hepatic Encephalopathy score ≥ 3), on continuous venovenous high-flow hemofiltration.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ten children were identified, six were transplanted (1/6 died) and four were not (3/4 died). TCD was performed several times per patient and the evolution of cerebral perfusion parameters was followed. Of interest, zero of six patients who survived lost end-diastolic velocity (EDV), whereas four of four patients who died did (difference, 100%; 95% CI, 37-100%; χ 2 , 9; degrees of freedom, 1; p = 0.0027). We failed to identify an association between pulsatility index (PI) or EDV, and severity of hepatic encephalopathy.

CONCLUSIONS

TCD was a noninvasive and bedside available tool to detect and screen for presence of abnormal cerebral flow in children with ALF, according to age-related reference values. TCD detected reduced EDV and elevated PI in children with ALF awaiting transplant who died compared with those who survived.

Whole Exome Sequencing Reveals Genetic Variants in HLA Class II Genes Associated With Transplant-free Survival of Indeterminate Acute Liver Failure

INTRODUCTION

Indeterminate acute liver failure (IND-ALF) is a rare clinical syndrome with a high mortality rate. Lacking a known etiology makes rapid evaluation and treatment difficult, with liver transplantation often considered as the only therapeutic option. Our aim was to identify genetic variants from whole exome sequencing data that might be associated with IND-ALF clinical outcomes.

METHODS

Bioinformatics analysis was performed on whole exome sequencing data for 22 patients with IND-ALF. A 2-tier approach was used to identify significant single-nucleotide polymorphisms (SNPs) associated with IND-ALF clinical outcomes. Tier 1 identified the SNPs with a higher relative risk in the IND-ALF population compared with those identified in control populations. Tier 2 determined the SNPs connected to transplant-free survival and associated with model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

RESULTS

Thirty-one SNPs were found associated with a higher relative risk in the IND-ALF population compared with those in controls, of which 11 belong to the human leukocyte antigen (HLA) class II genes but none for the class I. Further analysis showed that 5 SNPs: rs796202376, rs139189937, and rs113473719 of HLA-DRB5; rs9272712 of HLA-DQA1; and rs747397929 of IDO1 were associated with a higher probability of IND-ALF transplant-free survival. Using 3 selected SNPs, a model for the polygenic risk score was developed to predict IND-ALF prognoses, which are comparable with those by model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

DISCUSSION

Certain gene variants in HLA-DRB5, HLA-DQA1, and IDO1 were found associated with IND-ALF transplant-free survival. Once validated, these identified SNPs may help elucidate the mechanism of IND-ALF and assist in its diagnosis and management.

Pediatric Acute Liver Failure: A Clinicopathological Perspective

Pediatric acute liver failure (PALF) is a life-threatening disorder characterized by acute hepatocellular injury occurring in children without recognized underlying liver disease. The clinicopathologic evaluation of PALF requires a different approach from that in adults. The diagnostic considerations differ depending on the age, personal and family history, geographical region, and clinical presentation. Distinct entities such as gestational alloimmune liver disease, herpes simplex virus infection, and metabolic disorders should be considered in neonates with acute liver failure, while acetaminophen toxicity and autoimmune hepatitis are more frequently seen in older children and adolescents. An identified cause for PALF despite a negative complete evaluation (indeterminate) is lacking in 30 to 50% of cases. Although not routinely performed in the setting of PALF, liver biopsy may be helpful in assessing the etiology, potential mechanisms of injury, determining the appropriateness of liver transplantation, and prognostication of the patients. In this article, we review the clinicopathologic characteristics of PALF with an emphasis on general approach of pathologic evaluation and histopathologic characteristic of selected entities.

Indeterminate pediatric acute liver failure: Clinical characteristics of a temporal cluster of five children in the Netherlands in the spring of 2022

There is increasing global concern of severe acute hepatitis of unknown etiology in young children. In early 2022, our center for liver transplantation in the Netherlands treated five children who presented in short succession with indeterminate acute liver failure. Four children underwent liver transplantation, one spontaneously recovered. Here we delineate the clinical course and comprehensive diagnostic workup of these patients. Three of five patients showed a gradual decline of liver synthetic function and had mild neurological symptoms. Their clinical and histological findings were consistent with hepatitis. These three patients all had a past SARS-CoV-2 infection and two of them were positive for adenovirus DNA. The other two patients presented with advanced liver failure and encephalopathy and underwent dialysis as a bridge to transplantation. One of these children spontaneously recovered. We discuss this cluster of patients in the context of the currently elevated incidence of severe acute hepatitis in children.

Outcomes Analyses of Pediatric Acute Liver Failure Subjects Listed for Liver Transplantation

BACKGROUND

We characterized recent outcomes in US pediatric acute liver failure (PALF) subjects listed for liver transplantation (LT) using the Scientific Registry of Transplant Recipients (SRTR) database.

METHODS

Pediatric subjects listed for LT from 2002 to 2015 were assigned to the "PALF" group based on status 1/1A listing, INR >2, no hepatic artery thrombosis, and no primary graft nonfunction (N = 397). Subjects were assigned to the "non-PALF" group if listed with any status other than 1/1A (N = 4509).

RESULTS

The PALF group had more infants <3 months of age and males at listing for LT compared to the non-PALF group. Two-thirds of PALF subjects had an indeterminate etiology. LT waitlist survival was significantly worse in the PALF group compared to the non-PALF group. Likelihood of removal from the LT waitlist for being "too sick" was higher, while that of removal for "spontaneous recovery" was lower in PALF subjects. Post-LT short-term (30 days) and long-term (60 months) outcomes were also significantly worse in PALF versus non-PALF subjects. PALF subjects who underwent living-donor-liver-transplant (LDLT) had similar LT waitlist times and post-LT survival compared to those undergoing deceased-donor-liver-transplant (DDLT). Over the study period, we observed a decreased number of liver transplants, and increase in LT waitlist- and short-term post-LT-survival in PALF subjects.

CONCLUSION

LT waitlist and post-LT outcomes are worse in PALF subjects compared to non-PALF subjects. PALF subjects who undergo LDLT have similar waitlist times and post-LT outcomes compared to those undergoing DDLT.

Emergencies in paediatric hepatology

The aetiology of several liver diseases in children is age specific and many of these conditions have significant and potentially long-term clinical repercussions if not diagnosed early and managed in a timely fashion. We address 5 clinical scenarios that cover most of the diagnostic and therapeutic emergencies in children: infants with liver disease; acute liver failure; management of bleeding varices; liver-based metabolic disorders; and liver tumours and trauma. A wide spectrum of conditions that cause liver disease in infants may present as conjugated jaundice, which could be the only symptom of time-sensitive disorders - such as biliary atresia, metabolic disorders, infections, and haematological/alloimmune disorders - wherein algorithmic multistage testing is required for accurate diagnosis. In infantile cholestasis, algorithmic multistage tests are necessary for an accurate early diagnosis, while vitamin K, specific milk formulae and disease-specific medications are essential to avoid mortality and long-term morbidity. Management of paediatric acute liver failure requires co-ordination with a liver transplant centre, safe transport and detailed age-specific aetiological work-up - clinical stabilisation with appropriate supportive care is central to survival if transplantation is indicated. Gastrointestinal bleeding may present as the initial manifestation or during follow-up in patients with portal vein thrombosis or chronic liver disease and can be managed pharmacologically, or with endoscopic/radiological interventions. Liver-based inborn errors of metabolism may present as encephalopathy that needs to be recognised and treated early to avoid further neurological sequelae and death. Liver tumours and liver trauma are both rare occurrences in children and are best managed by a multidisciplinary team in a specialist centre.

The Role of Predictive Models in the Assessment of the Poor Outcomes in Pediatric Acute Liver Failure

OBJECTIVES

In children, acute liver failure (ALF) is a severe condition with high mortality. As some patients need liver transplantation (LT), it is essential to predict the fatal evolution and to refer them early for LT if needed. Our study aimed to evaluate the prognostic criteria and scores for assessing the outcome in children with ALF.

METHODS

Data of 161 children with ALF (54.66% female, mean age 7.66 ± 6.18 years) were analyzed based on final evolution (32.91% with fatal evolution or LT) and etiology. We calculated on the first day of hospitalization the PELD score (109 children), MELD, and MELD-Na score (52 children), and King's College Criteria (KCC) for all patients. The Nazer prognostic index and Wilson index for predicting mortality were calculated for nine patients with ALF in Wilson's disease (WD).

RESULTS

PELD, MELD, and MELD-Na scores were significantly higher in patients with fatal evolution (21.04 ± 13.28 vs. 13.99 ± 10.07, p = 0.0023; 36.20 ± 19.51 vs. 20.08 ± 8.57, p < 0.0001; and 33.07 ± 8.29 vs. 20.08 ± 8.47, p < 0.0001, respectively). Moreover, age, bilirubin, albumin, INR, and hemoglobin significantly differed in children with fatal evolution. Function to etiology, PELD, MELD, MELD-Na, and KCC accurately predicted fatal evolution in toxic ALF (25.33 vs. 9.90, p = 0.0032; 37.29 vs. 18.79, p < 0.0001; 34.29 vs. 19.24, p = 0.0002, respectively; with positive predicting value 100%, negative predicting value 88.52%, and accuracy 89.23% for King's College criteria). The Wilson index for predicting mortality had an excellent predictive strength (100% sensibility and specificity), better than the Nazer prognostic index.

CONCLUSIONS

Prognostic scores may be used to predict the fatal evolution of ALF in children in correlation with other parameters or criteria. Early estimation of the outcome of ALF is essential, mainly in countries where emergency LT is problematic, as the transfer to a specialized center could be delayed, affecting survival chances.

Acute Liver Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

CONTEXT

Develop evidence-based criteria for individual organ dysfunction.

OBJECTIVES

Evaluate current evidence and develop contemporary consensus criteria for acute liver dysfunction with associated outcomes in critically ill children.

DATA SOURCES

Electronic searches of PubMed and Embase conducted from January 1992 to January 2020, used medical subject heading terms and text words to characterize acute liver dysfunction and outcomes.

STUDY SELECTION

Studies evaluating critically ill children with acute liver dysfunction, assessed screening tools, and outcomes were included. Studies evaluating adults, infants ≤36 weeks gestational age, or animals or were reviews/commentaries, case series with sample size ≤10, or non-English language studies were excluded.

DATA EXTRACTION

Data were abstracted from each eligible study into a data extraction form along with risk of bias assessment by a task force member.

RESULTS

The systematic review supports criteria for acute liver dysfunction, in the absence of known chronic liver disease, as having onset of symptoms <8 weeks, combined with biochemical evidence of acute liver injury, and liver-based coagulopathy, with hepatic encephalopathy required for an international normalized ratio between 1.5 and 2.0.

LIMITATIONS

Unable to assess acute-on-chronic liver dysfunction, subjective nature of hepatic encephalopathy, relevant articles missed by reviewers.

CONCLUSIONS

Proposed criteria identify an infant, child, or adolescent who has reached a clinical threshold where any of the 3 outcomes (alive with native liver, death, or liver transplant) are possible and should prompt an urgent liaison with a recognized pediatric liver transplant center if liver failure is the principal driver of multiple organ dysfunction.

Pediatric acute liver failure: An experience of a pediatric intensive care unit from resource limited settings

INTRODUCTION

Pediatric acute liver failure is a rare and serious disease. Though liver transplantation is considered as the established treatment option for patients who are unlikely to recover with medical management, however, with the advancement of medical care there has been an increase in spontaneous regeneration of liver, obviating the need for liver transplantation. We identified the etiologies, outcome and prognostic factors of acute liver failure and the validity of the existing liver transplantation criteria to predict the outcome of pediatric acute liver failure.

MATERIALS AND METHODS

This was a retrospective study done from January 2014 to December 2019 in a tertiary pediatric critical care unit in South India. All children aged between 1 month to 18 years admitted with acute liver failure were enrolled.

RESULTS

Of 125 children with acute liver failure, the main etiologies were infections (32%), indeterminate (23%), paracetamol toxicity (21%), metabolic (13%) and others (11%). Dengue was the most common infection (55%). The median pediatric logistic organ dysfunction score at admission was 12 (4-27). Of 125 patients, 63.2% (n = 79) had spontaneous regeneration which was higher in paracetamol induced (92.3%) compared to non-paracetamol induced acute liver failure (55.5%). Only two patients underwent liver transplantation and 35% died. Peak alanine transaminase and use of inotropes significantly predicted the outcome of disease. Of 38 children meeting King's College Hospital criteria for liver transplantation, 57.9% had spontaneous regeneration and 36.8% died. Of 74 children meeting INR > 4 criteria, 54% (n = 40) had spontaneous regeneration and 43.2% died. INR >4 criteria was more sensitive than King's College Hospital criteria for predicting the need for liver transplantation.

CONCLUSION

Pediatric acute liver failure is caused by varied etiologies and infections were the commonest cause. Despite having a seriously ill cohort of patients, medical management resulted in spontaneous regeneration in the majority of children with acute liver failure. The use of inotropes, advanced hepatic encephalopathy, and peak alanine transaminase were predictors of poor outcome in children with acute liver failure and these patients could be considered for liver transplantation as available. Therefore, we may need to develop better predictors of pediatric acute liver failure in resource limited settings.

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper on the Diagnosis and Management of Pediatric Acute Liver Failure

ABSTRACT

Pediatric acute liver failure (PALF) is a rare, rapidly progressive clinical syndrome with significant morbidity and mortality. The phenotype of PALF manifests as abrupt onset liver dysfunction, which can be brought via disparate etiology. Management is reliant upon intensive clinical care and support, often provided by the collaborative efforts of hepatologists, critical care specialists, and liver transplant surgeons. The construction of an age-based diagnostic approach, the identification of a potential underlying cause, and the prompt implementation of appropriate therapy can be lifesaving; however, the dynamic and rapidly progressive nature of PALF also demands that diagnostic inquiries be paired with monitoring strategies for the recognition and treatment of common complications of PALF. Although liver transplantation can provide a potential life-saving therapeutic option, the ability to confidently determine the certainness that liver transplant is needed for an individual child has been hampered by a lack of adequately tested clinical decision support tools and accurate predictive models. Given the accelerated progress in understanding PALF, we will provide clinical guidance to pediatric gastroenterologists and other pediatric providers caring for children with PALF by presenting the most recent advances in diagnosis, management, pathophysiology, and associated outcomes.

Higher circulating natural killer cells and lower lactate levels at admission predict spontaneous survival in non-acetaminophen induced acute liver failure

Massive cellular necrosis in acute liver failure (ALF) is dominantly immune mediated and innate immune cells are major pathophysiological determinants in liver damage. In fifty ALF and fifteen healthy, immune cells phenotyping by flow-cytometry, DAMPs using ELISA were analysed and correlated with clinical and biochemical parameters. ALF patients (aged 27 ± 9 yr, 56% males, 78% viral aetiology) showed no difference in neutrophils and classical monocytes, but significantly increased intermediate monocytes (CD14⁺CD16⁺) (p < 0.01), decreased non-classical monocytes (CD14^-CD16⁺) and CD3^-veCD16⁺CD56⁺ NK cells compared to HC. ALF patients who survived, showed higher NK cells (9.28 vs. 5.1%, p < 0.001) among lymphocytes and lower serum lactate levels (6.1 vs. 28, Odds ratio 2.23, CI 1.27-3.94) than non- survivors had higher. Logistic regression model predicted the combination of lactate levels with NK cell percentage at admission for survival. In conclusion, Combination of NK cell frequency among lymphocytes and lactate levels at admission can reliably predict survival of ALF patients.

Pediatric chronic liver failure-sequential organ failure assessment score and outcome of acute liver failure in children

Aim of the study

Liver transplantation remains the only definitive treatment for children with acute liver failure proven to have irreversible liver injury. Many prognostic models have been used for outcome prediction in pediatric acute liver failure to select patients in a real need of liver transplantation, but unfortunately all have shown inconsistent reproducibility and prognostic accuracy. The aim of this study was to evaluate the pediatric chronic liver failure sequential organ failure assessment (pCLIF-SOFA) score as a predictor of pediatric acute liver failure outcome.

Material and methods

Clinical and laboratory data of 41 children with acute liver failure admitted to the National Liver Institute – Menoufia University were collected retrospectively and used for calculation of both pCLIF-SOFA and Pediatric End-Stage Liver Disease (PELD)/Model for End-Stage Liver Disease (MELD) scores on the day of admission, then statistical analysis was performed to identify the ability of these scores to predict the outcome.

Results

According to the outcome, children enrolled in this study were allocated to survived (n = 16) and died (n = 25) groups, which were age and sex matched. The non-survival group had significantly higher values of both pCLIF-SOFA score (11 [7-13]) and PELD/MELD score (36 [18-42]) than those of the survival group (8 [7-11], 27.5 [15-45]; p < 0.001, p = 0.004) respectively. Both pCLIF-SOFA and PELD/MELD scores at cut-off values > 8 and > 30 respectively on admission could predict death in children with acute liver failure (ALF) with high sensitivity, but with higher specificity, positive and negative predictive values for pCLIF-SOFA.

Conclusions

pCLIF-SOFA is a good predictor of death in pediatric acute liver failure.

Successful ABO-incompatible living donor liver transplant for acute liver failure secondary to Hodgkin's Lymphoma in a child

We present a case of pediatric ALF, secondary to hepatic HL, who underwent a successful ABOi living donor liver transplant. We believe this is the first such case reported in academic literature. HL with liver involvement is extremely rare and is not considered an indication for transplantation. The 12-year-old, male patient presented with a viral illness prodrome, and parvovirus was detected in pre-transplant laboratory cultures. He received an ABOi living donor liver graft followed by a course of plasma exchange and rituximab after which standard immunosuppression was used. The HL was diagnosed on hepatic biopsy post-transplant. Subsequently, the patient commenced six cycles of R-CHOP chemotherapy. During chemotherapy, we stopped tacrolimus and mycophenolate mofetil. Immunosuppression was maintained with corticosteroids in-between cycles. The patient is alive and reports good quality of life 1-year post-transplant. The HL is in remission. During the post-operative period, the patient experienced four episodes of neutropenia, a bile leak, and gram-negative sepsis. One episode of acute rejection has been treated. Although we did not initially transplant the patient for ALF secondary to HL, its subsequent diagnosis and the patient's response to management raises many issues that warrant consideration. While the findings from a single case cannot be generalized, this could be a "proof of concept" for liver transplantation in hepatic HL. We hope it will facilitate discussions and potentially expand therapeutic options available to this very small group patients.

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.

Timing of liver transplantation for pediatric acute liver failure due to mushroom poisoning: a case report and literature review

Background

Pediatric acute liver failure is a rare, life-threatening illness. Mushroom poisoning is a rare etiology. For patients with irreversible pediatric acute liver failure, liver transplantation is the ultimate lifesaving therapy. However, it is difficult to determine the optimal timing of transplantation. Here, we present a case of pediatric acute liver failure due to mushroom poisoning in northeastern China. He was treated with liver transplantation and recovered. To our knowledge, there are few reports about liver transplantation for pediatric acute liver failure caused by mushroom poisoning in mainland China.

Case presentation

The patient was a previously healthy 9-year-old boy who gradually developed nausea, vomiting, jaundice and coma within 5 days after ingesting mushrooms. He was diagnosed with mushroom poisoning and acute liver failure. He was treated with conservative care but still deteriorated. On the 7th day after poisoning, he underwent LT due to grade IV hepatic encephalopathy. Twenty days later, he recovered and was discharged. A review of the literature revealed that the specific criteria and optimal timing of transplantation remain to be determined.

Conclusions

Patients with pediatric acute liver failure should be transferred to a center with a transplant unit early. Once conservative treatment fails, liver transplantation should be performed.

Development of a Prognostic Score to Predict Mortality in Patients With Pediatric Acute Liver Failure

OBJECTIVES

This study aims to develop a new prognostic score based on changes in serial laboratory data from patients with pediatric acute liver failure (PALF).

METHODS

We retrospectively reviewed data on 146 patients with PALF at the Seoul National University Children Hospital (SNUCH) and the Asan Medical Center (AMC). Daily morning laboratory records were obtained for up to 7 days after diagnosis of PALF: total bilirubin (TB) (mg/dL), international normalized ratio for prothrombin time (INR) at enrolment; peak TB, peak INR, peak ammonia (μmol/L); the difference between the peak TB and TB at enrollment (ie, Δpeak TB), the difference between the peak INR and INR at enrollment (ie, Δpeak INR), the maximum change in serial TB (ie, Δdaily TB), the maximum change in serial INR level (ie, Δdaily INR). We assigned nontransplanted patients in SNUCH and AMC to derivation and validation cohorts, respectively.

RESULTS

Δpeak TB, Δdaily TB, Δpeak INR, and Δdaily INR were significantly higher in the nonsurvival group. We developed a new score that can predict mortality in nontransplanted patients (derivation cohort n = 42, validation cohort n = 33). PALF-Delta score (PALF-Ds) = [0.232 × Δpeak TB (mg/dL)] + [2.263 × Δdaily INR] + [0.013 × peak ammonia (μmol/L)] - 4.498. The score yielded AUC 0.918 in the derivation cohort (sensitivity 81%, specificity 91%) and AUC 0.947 in the validation cohort (sensitivity 100%, specificity 89%).

CONCLUSION

A prognostic scoring system using the change of TB/INR may be useful for predicting mortality in patients with PALF.

A novel, bedside, etiology specific prognostic model (Peds-HAV) in hepatitis A induced pediatric acute liver failure

BACKGROUND

Hepatitis A virus (HAV) is the commonest cause of pediatric acute liver failure (PALF) in developing countries. Our objective was to develop and validate a HAV-etiology specific prognostic model in PALF.

METHODS

All children with HAV induced PALF (IgM HAV reactive) were included. Outcome was defined at day 28. Only those with death or native liver survival were included. The model (Peds-HAV) was derived using the independent predictors of outcome and validated in a prospective independent cohort.

RESULTS

Hepatitis A accounted for 131 (45.9%) of total 285 PALF. After excluding 11 children who underwent liver transplant, 120 children (74 survivors and 46 death) were included. The first 75 patients formed the derivation cohort and the next 45 patients formed the prospective validation cohort. In the derivation cohort, INR: OR 2.208, (95% CI 1.321-3.690), p = 0.003, grade of hepatic encephalopathy (HE): OR 3.078, (95% CI 1.017-9.312), p = 0.047 and jaundice-to-HE interval: OR 1.171, (95% CI 1.044-1.314), p = 0.007 were independent predictors of death. The final model comprised three criteria: (1) presence of grade 3-4 HE, (2) INR greater than 3.1, and (3) jaundice to HE interval more than 10 days. Presence of 2 or more of these criteria predicted death with 90% sensitivity, 81.4% specificity and 84.9% accuracy. Peds-HAV model was superior to existing prognostic models. In the validation cohort, Peds-HAV model predicted death with 83.3% sensitivity and 92.6% specificity.

CONCLUSION

Peds-HAV model is a simple, bedside, dynamic, etiology (HAV) specific prognostic model based on 3 objective parameters with optimum sensitivity and specificity, hence should be used as liver transplant listing criteria in HAV induced PALF.

Changing Etiologies and Prognostic Factors in Pediatric Acute Liver Failure

After the implementation of universal hepatitis A virus vaccination in Argentina, the outcome of pediatric acute liver failure (PALF) remains unknown. We aimed to identify variables associated with the risk of liver transplantation (LT) or death and to determine the causes and short-term outcomes of PALF in Argentina. We retrospectively included 135 patients with PALF listed for LT between 2007 and 2016. Patients with autoimmune hepatitis (AIH), Wilson's disease (WD), or inborn errors of metabolism (IEM) were classified as PALF-chronic liver disease (CLD), and others were classified as "pure" PALF. A logistic regression model was developed to identify factors independently associated with death or need of LT and risk stratification. The most common etiologies were indeterminate (52%), AIH (23%), WD (6%), and IEM (6%). Overall, transplant-free survival was 35%, whereas 50% of the patients underwent LT and 15% died on the waiting list. The 3-month risk of LT or death was significantly higher among patients with pure PALF compared with PALF-CLD (76.5% versus 42.5%; relative risk, 1.8 [1.3-2.5]; P < 0.001), and 3 risk factors were independently associated with worse outcome: international normalized ratio (INR) ≥3.5 (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.3-7.2]), bilirubin ≥17 mg/dL (OR, 4.4; 95% CI, 1.9-10.3]), and pure PALF (OR, 3.8; 95% CI, 1.6-8.9). Patients were identified by the number of risk factors: Patients with 0, 1, or ≥2 risk factors presented a 3-month risk of worse outcome of 17.6%, 36.6%, and 82%, respectively. In conclusion, although lacking external validation, this simple risk-staging model might help stratify patients with different transplant-free survival rates and may contribute to establishing the optimal timing for LT.

Transplant-free Survival in Chronic Liver Disease Presenting as Acute Liver Failure in Childhood

BACKGROUND

In adults, the absence of a preexisting chronic liver disease (CLD) is required to diagnose acute liver failure (ALF). The pediatric classification does not consider this aspect, thus previous studies pooled together children with ALF and children with unknown CLD presenting with acute hepatic decompensation (ALF-CLD). We aimed to compare prevalence, features, and outcome of children with ALF-CLD to those with a proper ALF.

METHODS

Patients admitted between 1996 and 2017 because of ALF defined by Pediatric Acute Liver Failure criteria (raised transaminases, International Normal Ratio ≥2.0, no history of liver disease) were classified as ALF-CLD if diagnosed with autoimmune hepatitis, Wilson disease, Budd-Chiari syndrome, hepatitis B virus reactivation, inborn errors of metabolism. The others were classified as ALF.

RESULTS

Seventy-four children (median age, 4 years; 1.0-8.8; male/female, 36/38] with ALF were found; 18 of <1 year of age were excluded. Fifty-six (median age, 6.6 years; 2.7-11.7; male/female, 23/33], 22 with ALF-CLD (autoimmune hepatitis, n = 14; Wilson disease, n = 6; inborn errors of metabolism, n = 2) and 34 with ALF (paracetamol overdose, n = 6; viral infections, n = 3; mushroom poisoning, n = 5; indeterminate, n = 20) were compared. In ALF-CLD, the median age at onset was higher, alanine aminotransferase, albumin, and International Normal Ratio levels were lower, splenomegaly, ascites, and cirrhosis were more common (all P < 0.01). On multivariate analysis, the diagnosis of ALF-CLD was an independent predictor of transplant-free survival (P = 0.006).

CONCLUSIONS

In children, ALF-CLD is common, has peculiar features, and is associated with a favorable outcome. This study suggests the need to distinguish this entity from other forms of ALF in children.

Liver Transplant Listing in Pediatric Acute Liver Failure: Practices and Participant Characteristics

Liver transplant (LT) decisions in pediatric acute liver failure (PALF) are complex. Three phases of the PALF registry, containing data on 1,144 participants over 15 years, were interrogated to characterize clinical features associated with listing status. A decrease in the cumulative incidence of listing (P < 0.005) and receiving (P < 0.05) LT occurred without an increase in the cumulative incidence of death (P = 0.67). Time to listing was constant and early (1 day; quartiles 1-3 = 0-2; P = 0.88). The most frequent reasons for not listing were "not sick enough" and "medically unsuitable." Participants listed for LT were more likely male, with coma grade scores >0; had higher international normalized ratio, bilirubin, lactate, and venous ammonia; and had lower peripheral lymphocytes and transaminase levels compared to those deemed "not sick enough." Participants listed versus those deemed "medically unsuitable" were older; had higher serum aminotransferase levels, bilirubin, platelets, and albumin; and had lower lactate, venous ammonia, and lymphocyte count. An indeterminate diagnosis was more prevalent in listed participants. Ventilator (23.8%) and vasopressor (9.2%) support occurred in a significant portion of listed participants but less frequently than in those who were not "medically suitable." Removal from the LT list was a rare event. Conclusion: The cumulative incidence of listing for and receiving LT decreased throughout the PALF study without an increase in the cumulative incidence of death. While all participants fulfilled entry criteria for PALF, significant differences were noted between participants listed for LT and those deemed "not sick enough" as well as those who were "medically unsuitable." Having an indeterminate diagnosis and a requirement for cardiopulmonary support appeared to influence decisions toward listing; optimizing listing decisions in PALF may reduce the frequency of LT without increasing the frequency of death.

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.

Acute liver failure: A review for emergency physicians

INTRODUCTION

Acute liver failure (ALF) remains a high-risk clinical presentation, and many patients require emergency department (ED) management for complications and stabilization.

OBJECTIVE

This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of ALF.

DISCUSSION

While ALF remains a rare clinical presentation, surveillance data suggest an overall incidence between 1 and 6 cases per million people every year, accounting for 6% of liver-related deaths and 7% of orthotopic liver transplants (OLT) in the U.S. The definition of ALF includes neurologic dysfunction, an international normalized ratio ≥ 1.5, no prior evidence of liver disease, and a disease course of ≤26 weeks, and can be further divided into hyperacute, acute, and subacute presentations. There are many underlying etiologies, including acetaminophen toxicity, drug induced liver injury, and hepatitis. Emergency physicians will be faced with several complications, including encephalopathy, coagulopathy, infectious processes, renal injury, and hemodynamic instability. Critical patients should be evaluated in the resuscitation bay, and consultation with the transplant team for appropriate patients improves patient outcomes. This review provides several guiding principles for management of acute complications. Using a pathophysiological-guided approach to the management of ALF associated complications is essential to optimizing patient care.

CONCLUSIONS

ALF remains a rare clinical presentation, but has significant morbidity and mortality. Physicians must rapidly diagnose these patients while evaluating for other diseases and complications. Early consultation with a transplantation center is imperative, as is identifying the underlying etiology and initiating symptomatic care.

Histopathologic Analysis in Sudden Infant and Child Deaths: A Practical Approach

The forensic pathologist responsible for sudden unexpected death (SUD) investigation in the pediatric setting faces many challenges. It usually takes many years to obtain reasonable experience and exposure to the wide variety of diseases that may present as SUD in a pediatric context, and to appreciate the differences in the etiology and clinical context between the pediatric and adult SUD setting. In pediatric SUD, it is necessary to conduct a systematic, pediatric-focused autopsy investigation including extensive histopathological assessment and ancillary testing. Postmortem histologic findings in the context of SUD in the pediatric population are often subtle and distinctly different from those seen in the adult population. The pathologist must have an understanding of both developmental and pathological processes in order to correctly interpret the findings during a pediatric autopsy. A system-based, histopathology-focused review of common entities, normal variants, and incidental findings that can prove challenging will be discussed. For the forensic pathologist tasked with pediatric SUD autopsies, development of a strong collaborative relationship with a pediatric pathologist and/or neuropathologist to assist with histopathological analysis is strongly endorsed.

Medical Management of Acute Liver Failure

Pediatric acute liver failure is a rapidly progressive, life-threatening, and devastating illness in children without preexisting liver disease. Due to the rarity and heterogeneity of this syndrome, there is a significant lack of data to guide evaluation and management of this disease. Most of our practice is extrapolated from adult literature and guidelines. This leads to significant controversies in medical management of acute liver failure in children. With advances in critical care, there has been a tremendous improvement in outcomes with decreased morbidity and mortality; however, there is a dire need for more research in this field. This chapter discusses challenges as well as controversies in diagnostic evaluation and management of this rare but potentially fatal disease. Latest developments in supportive care of liver failure, including advances in the area of liver support systems, are also discussed.

Using time-varying models to estimate post-transplant survival in pediatric liver transplant recipients

PURPOSE

To distinguish clinical factors that have time-varying (as opposed to constant) impact upon patient and graft survival among pediatric liver transplant recipients.

METHODS

Using national data from 2002 through 2013, we examined potential clinical and demographic covariates using Gray's piecewise constant time-varying coefficients (TVC) models. For both patient and graft survival, we estimated univariable and multivariable Gray's TVC, retaining significant covariates based on backward selection. We then estimated the same specification using traditional Cox proportional hazards (PH) models and compared our findings.

RESULTS

For patient survival, covariates included recipient diagnosis, age, race/ethnicity, ventilator support, encephalopathy, creatinine levels, use of living donor, and donor age. Only the effects of recipient diagnosis and donor age were constant; effects of other covariates varied over time. We retained identical covariates in the graft survival model but found several differences in their impact.

CONCLUSION

The flexibility afforded by Gray's TVC estimation methods identify several covariates that do not satisfy constant proportionality assumptions of the Cox PH model. Incorporating better survival estimates is critical for improving risk prediction tools used by the transplant community to inform organ allocation decisions.

Management of Acute Liver Failure: A Pediatric Perspective

Purpose of Review

Pediatric acute liver failure is a rare, complex, rapidly progressing, and life-threatening illness. Majority of pediatric acute liver failures have unknown etiology. This review intends to discuss the current literature on the challenging aspects of management of acute liver failure.

Recent Findings

Collaborative multidisciplinary approach for management of patients with pediatric acute liver failure with upfront involvement of transplant hepatologist and critical care specialists can improve outcomes of this fatal disease. Extensive but systematic diagnostic evaluation can help to identify etiology and guide management. Early referral to a transplant center with prompt liver transplant, if indicated, can lead to improved survival in these patients.

Summary

Prompt identification and aggressive management of pediatric acute liver failure and related comorbidities can lead to increased transplant-free survival and improved post-transplant outcomes, thus decreasing mortality and morbidity associated with this potential fatal condition.