Outcome of Acetaminophen-Induced Acute Liver Failure Managed Without Intracranial Pressure Monitoring or Transplantation

Update on the management of acute liver failure

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Severely Hyperammonemic Acute Liver Failure due to Paracetamol Overdose: The Impact of High-Intensity Continuous Renal Replacement Therapy

INTRODUCTION

Paracetamol (acetaminophen)-induced acute liver failure (ALF) with severe hyperammonemia (ammonia >100 µmol⋅L-1) is a life-threatening condition. A strategy based on high-intensity continuous renal replacement therapy (CRRT) without early (up to day seven) transplantation may enable clinicians to safely identify which patients can recover and survive and which patients require transplantation.

METHODS

We conducted a single-center, retrospective cohort study of patients with severely hyperammonemic paracetamol-induced ALF. The primary outcome was early transplant-free survival.

RESULTS

We studied 84 patients (median age: 38; female sex: 79 [85%]) over a 12-year period (median ammonia level at ICU admission: 153 µmol⋅L-1; median peak aspartate aminotransferase (AST): 10,029 U⋅L-1; median lactate: 5.0 mmol⋅L-1; and median INR: 4.4) and 55 (65%) with King's College criteria for transplantation. Overall, 87% received high-intensity CRRT (92% in 2020-2023). Median CRRT intensity was 54 mL⋅kg-1⋅hr-1 within the first 48 h and increased by 1.8 mL⋅kg-1⋅hr-1 per year during the study period (p = 0.002). Transplant-free survival to day 7 was 86% in 2011-2023 and 96% in 2020-2023. Overall, only 4 patients were transplanted and only 1 (4%) in 2020-2023. On multivariable Cox analysis, factors independently associated with failure to achieve day seven transplant-free survival were higher APACHE III score (HR = 1.05, 95% CI: 1.02-1.08), higher lactate (HR = 1.27, 95% CI: 1.12-1.44), and lower platelet count at ICU admission (HR = 0.85, 95% CI: 0.78-0.93) and the median effluent dose applied within the first 48 h of ICU admission (HR = 0.67, 95% CI: 0.46-0.98).

CONCLUSIONS

Early transplant-free survival is achievable in most patients with paracetamol-induced ALF and severe hyperammonemia with a treatment based on high-intensity CRRT. Such transplant-free survival increased over time together with increased CRRT dose.

Acute liver failure: A practical update

Acute liver failure is a rare and dynamic condition, with a broad aetiology and an incompletely understood pathophysiology. Management of this life-threatening disease requires critical care and organ support and frequently early liver transplantation. Proper identification, prevention and treatment of complications such as intracranial hypertension and sepsis are critical to optimising outcomes. The identification of the cause of acute liver failure and the prompt initiation of the aetiological treatment can also improve prognosis. Survival has progressively improved in parallel to advances in medical treatment. Intracranial hypertension complicating hepatic encephalopathy is less frequent than in the past and intracranial pressure monitoring now relies on non-invasive techniques. Current prognostic models have good accuracy to identify patients who will die without liver transplantation but are not able to identify those in whom transplantation is futile. New prognostic markers to select patients for transplantation are still in the pipeline. Therapeutic plasma exchange and, in some centers, early renal replacement therapy are well established treatments for the disease. The use of other artificial liver devices in clinical practice is not supported by evidence. This review is intended to provide a clinical update on the management of acute liver failure, incorporating the most recent advances in the field.

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

Evaluation of transcranial Doppler use in patients with acute liver failure listed for emergency liver transplantation

PURPOSE

Acute liver failure (ALF) is characterized by hepatic encephalopathy (HE) often due to intracranial hypertension (ICH). The risk/benefit-balance of intraparenchymal pressure catheter monitoring is controversial during ALF.

AIMS

Perform an evaluation of transcranial Doppler (TCD) use in patients with ALF listed for emergency liver transplantation.

MATERIAL AND METHODS

Single center retrospective cohort study including all patients registered on high emergency LT list between 2012 and 2018. All TCD measurements performed during ICU stay after listing and after LT (when performed) were recorded. TCD was considered abnormal when pulsatility index (PI) was >1.2.

RESULTS

Among 106 patients with ALF, forty-seven (44%) had a TCD while on list. They had more severe liver and extrahepatic organ failure. When performed, TCD was abnormal in 51% of patients. These patients more frequently developed ICH events (45% vs. 13%, p = .02) and more frequently required increase in sedative drugs and vasopressors. While 22% of patients with normal TCD spontaneously survived, all of those with abnormal TCD died or were transplanted (p = .02). All transplanted patients who had abnormal exams normalized their TCD within 2 (1-2) days after LT.

CONCLUSION

TCD may be a useful non-invasive tool for ICH detection and management, then guide sedation withdrawal.

Acute liver failure

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Creatinine-lactate score predicts mortality in non-acetaminophen-induced acute liver failure in patients listed for liver transplantation

BACKGROUND

The aim of this study was to analyze prognostic indicators of in-hospital mortality among patients listed for urgent liver transplantation (LT) for non-acetaminophen (APAP)-induced acute liver failure (ALF).

METHODS

ALF patients listed for LT according to the King's College Criteria were retrospectively reviewed. Variables were recorded from medical records and electronic databases (HCMED and RedCap).

RESULTS

The study included 100 patients, of which 69 were subject to LT and 31 died while waiting for LT. Patients were 35.5 ± 14.73 years old, and 78% were females. The main etiologies were virus (17%), drug-induced (32%), autoimmune (15%), and indeterminate hepatitis (31%). The prioritization-to-LT time interval was 1.5 days (0-9). The non-LT patients showed higher lactate (8.71 ± 5.36 vs. 4.48 ± 3.33 mmol/L), creatinine (229 ± 207 vs. 137 ± 136 µm/L), MELD (44 ± 8 vs. 38 ± 8), and BiLE scores (15.8 ± 5.5 vs. 10.3 ± 4.1) compared to LT patients (p < 0.05). Multiple logistic regression analysis identified creatinine and lactate as independent prognostic factors, and a creatinine-lactate (CL) score was developed. ROC analysis showed that creatinine, lactate, MELD, BiLE, and CL scores had considerable specificity (71-88%), but only BiLE, lactate, and CL presented high sensitivities (70%, 80%, and 87% respectively). AUCs were 0.696 for creatinine, 0.763 for lactate, 0.697 for MELD, 0.814 for BiLE, and 0.835 for CL.

CONCLUSIONS

CL and BiLE scores predict mortality with more accuracy than MELD in patients with ALF during prioritization time. Creatinine and lactate are independent prognostic factors for mortality.

The Crashing Toxicology Patient

This article examines, using an organ-systems based approach, rapid diagnosis, resuscitation, and critical care management of the crashing poisoned patient in the emergency department. The topics discussed in this article include seizures and status epilepticus, respiratory failure, cardiovascular collapse and mechanical circulatory support, antidotes and drug-specific therapies, acute liver failure, and extracorporeal toxin removal.

Evaluating lactate prognostic value in children suspected of acetaminophen-induced liver failure in Liberia

BACKGROUND

The prognostic significance of hyperlactatemia in young children with liver injury suspected to be attributed to repeated supratherapeutic doses of acetaminophen remain understudied.

METHODS

We conducted a retrospective medical chart review including children aged <5 years admitted with hepatocellular injury. The study was conducted in Bardnesville Junction Hospital operated by Médecins Sans Frontières in Monrovia, Liberia.

RESULTS

We analyzed 95 children with liver injury in whom a blood lactate measurement on admission was available. Eighty children (84%) were aged <2 years; 49 children (52%) died during hospitalization. The median acetaminophen concentration on admission was 20 mg/L with 60 (70%) children presenting concentrations exceeding 10 mg/L. Median lactate was significantly higher in children who died (10.7 mmol/L; interquartile range (IQR): 8.5-15.7) than those who survived (6.1 mmol/L; IQR: 4.1-8.5), P value < 0.001). The optimal threshold obtained was 7.2 mmol/L with a sensitivity of 84% and specificity 70% (area under curve = 0.80). The previously established thresholds of 3.5 and 4 mmol/L lactate had very low specificity identifying non-survival in children included in this study.

CONCLUSION

In this setting, young children with ALF possibly attributed to acetaminophen toxicity were unlikely to survive if the venous blood lactate concentration exceeded 7.2 mmol/L.

Metabolomics analysis reveals the protective effect of quercetin-3-O-galactoside (Hyperoside) on liver injury in mice induced by acetaminophen

We investigated the protective effect of Hyperoside (HPS) on liver injury induced by acetaminophen (APAP) in C57 mice. HPS was administered orally for 7 days and APAP was administered orally on the 7th day. Serum and liver samples were then collected for biochemical analyses, histopathology assessments, and metabolomics studies. Metabolites were assessed using a UHPLC-MS system. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to process the data. Pathway analyses were performed using Metaboanalyst 4.0. Western blot and qRT-PCR were used to determine the protein and mRNA levels, respectively. HPS interacted with active sites in CYP2E1 and caused protein degradation. In conclusion, our results suggested that HPS prevented the oxidative stress-induced liver injury caused by APAP. PRACTICAL APPLICATIONS: Hyperoside was shown to have potential protective and therapeutic effects against liver diseases. Male C57 mice were used to perform pharmacodynamic, pharmacology, and metabolomics evaluations. At a dose of 60 mg/kg, HPS prevented oxidative stress-induced liver injury caused by APAP by regulating the glutathione-related metabolites and enzymes through the inhibition of CYP2E1.

Abdominal Organ Transplantation: Noteworthy Literature in 2019

In the year 2019, we identified and screened over 400 peer-reviewed publications on pancreatic transplantation, over 200 on intestinal transplantation, and over 1900 on kidney transplantation. The liver transplantation section focuses on and features selected articles among 70 clinical trials published in 2019. This review highlights noteworthy literature pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. We explore a broad range of topics, including risks for and prediction of perioperative complications, updated indications for transplantation, recommendations on perioperative management, including Enhanced Recovery After Surgery programs, and topics relevant to optimization of patient and graft outcomes and survival.