Therapeutic hypothermia in acute liver failure: a multicenter retrospective cohort analysis

Future directions in acute liver failure

Acute liver failure (ALF) describes a clinical syndrome of rapid hepatocyte injury leading to liver failure manifested by coagulopathy and encephalopathy in the absence of pre-existing cirrhosis. The hallmark diagnostic features are a prolonged prothrombin time (ie, an international normalized ratio of prothrombin time of ≥1.5) and any degree of mental status alteration (HE). As a rare, orphan disease, it seemed an obvious target for a multicenter network. The Acute Liver Failure Study Group (ALFSG) began in 1997 to more thoroughly study and understand the causes, natural history, and management of ALF. Over the course of 22 years, 3364 adult patients were enrolled in the study registry (2614 ALF and 857 acute liver injury-international normalized ratio 2.0 but no encephalopathy-ALI) and >150,000 biosamples collected, including serum, plasma, urine, DNA, and liver tissue. Within the Registry study sites, 4 prospective substudies were conducted and published, 2 interventional ( N -acetylcysteine and ornithine phenylacetate), 1 prognostic [ 13 C-methacetin breath test (MBT)], and 1 mechanistic (rotational thromboelastometry). To review ALFSG's accomplishments and consider next steps, a 2-day in-person conference was held at UT Southwestern Medical Center, Dallas, TX, entitled "Acute Liver Failure: Science and Practice," in May 2022. To summarize the important findings in the field, this review highlights the current state of understanding of ALF and, more importantly, asks what further studies are needed to improve our understanding of the pathogenesis, natural history, and management of this unique and dramatic condition.

Temperature control after cardiac arrest

Managing temperature is an important part of post-cardiac arrest care. Fever or hyperthermia during the first few days after cardiac arrest is associated with worse outcomes in many studies. Clinical data have not determined any target temperature or duration of temperature management that clearly improves patient outcomes. Current guidelines and recent reviews recommend controlling temperature to prevent hyperthermia. Higher temperatures can lead to secondary brain injury by increasing seizures, brain edema and metabolic demand. Some data suggest that targeting temperature below normal could benefit select patients where this pathology is common. Clinical temperature management should address the physiology of heat balance. Core temperature reflects the heat content of the head and torso, and changes in core temperature result from changes in the balance of heat production and heat loss. Clinical management of patients after cardiac arrest should include measurement of core temperature at accurate sites and monitoring signs of heat production including shivering. Multiple methods can increase or decrease heat loss, including external and internal devices. Heat loss can trigger compensatory reflexes that increase stress and metabolic demand. Therefore, any active temperature management should include specific pharmacotherapy or other interventions to control thermogenesis, especially shivering. More research is required to determine whether individualized temperature management can improve outcomes.

Guidelines for the Management of Adult Acute and Acute-on-Chronic Liver Failure in the ICU: Neurology, Peri-Transplant Medicine, Infectious Disease, and Gastroenterology Considerations

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for adults with acute liver failure (ALF) or acute on chronic liver failure (ACLF) in the ICU.

DESIGN

The guideline panel comprised 27 members with expertise in aspects of care of the critically ill patient with liver failure or methodology. We adhered to the Society of Critical Care Medicine standard operating procedures manual and conflict-of-interest policy. Teleconferences and electronic-based discussion among the panel, as well as within subgroups, served as an integral part of the guideline development.

INTERVENTIONS

In part 2 of this guideline, the panel was divided into four subgroups: neurology, peri-transplant, infectious diseases, and gastrointestinal groups. We developed and selected Population, Intervention, Comparison, and Outcomes (PICO) questions according to importance to patients and practicing clinicians. For each PICO question, we conducted a systematic review and meta-analysis where applicable. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence to decision framework to facilitate recommendations formulation as strong or conditional. We followed strict criteria to formulate best practice statements.

MEASUREMENTS AND MAIN RESULTS

We report 28 recommendations (from 31 PICO questions) on the management ALF and ACLF in the ICU. Overall, five were strong recommendations, 21 were conditional recommendations, two were best-practice statements, and we were unable to issue a recommendation for five questions due to insufficient evidence.

CONCLUSIONS

Multidisciplinary, international experts formulated evidence-based recommendations for the management ALF and ACLF patients in the ICU, acknowledging that most recommendations were based on low quality and indirect evidence.

Issues of intensive care and liver transplantation tactics in fulminant liver failure

Fulminant liver failure is usually characterized as severe acute liver injury with encephalopathy and synthetic dysfunction (international normalized ratio [INR] ≥1.5) in a patient without cirrhosis or previous liver disease. Management of patients with acute liver failure includes ensuring that the patient is cared for appropriately, monitoring for worsening liver failure, managing complications, and providing nutritional support. Patients with acute liver failure should be treated at a liver transplant center whenever possible. Serial laboratory tests are used to monitor the course of a patient's liver failure and to monitor for complications. It is necessary to monitor the level of aminotransferases and bilirubin in serum daily. More frequent monitoring (three to four times a day) of blood coagulation parameters, complete blood count, metabolic panels, and arterial blood gases should be performed. For some causes of acute liver failure, such as acetaminophen intoxication, treatment directed at the underlying cause may prevent the need for liver transplantation and reduce mortality. Lactulose has not been shown to improve overall outcomes, and it can lead to intestinal distention, which can lead to technical difficulties during liver transplantation. Early in acute liver failure, signs and symptoms of cerebral edema may be absent or difficult to detect. Complications of cerebral edema include increased intracranial pressure and herniation of the brain stem. General measures to prevent increased intracranial pressure include minimizing stimulation, maintaining an appropriate fluid balance, and elevating the head of the patient's bed. For patients at high risk of developing cerebral edema, we also offer hypertonic saline prophylaxis (3%) with a target serum sodium level of 145 to 155 mEq/L (level 2C). High-risk patients include patients with grade IV encephalopathy, high ammonia levels (>150 µmol/L), or acute renal failure, and patients requiring vasopressor support. Approximately 40 % of patients with acute liver failure recover spontaneously with supportive care. Predictive models have been developed to help identify patients who are unlikely to recover spontaneously, as the decision to undergo liver transplant depends in part on the likelihood of spontaneous recovery of the liver. However, among those who receive a transplant, the one-year survival rate exceeds 80 %, making this treatment the treatment of choice in this difficult patient population.

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.

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.

Clinical and Neurologic Outcomes in Acetaminophen-Induced Acute Liver Failure: A 21-Year Multicenter Cohort Study

BACKGROUND & AIMS

Acetaminophen (APAP)-induced acute liver failure (ALF) is a rare disease associated with high mortality rates. This study aimed to evaluate changes in interventions, psychosocial profile, and clinical outcomes over a 21-year period using data from the ALF Study Group registry.

METHODS

A retrospective review of this prospective, multicenter cohort study of all APAP-ALF patients enrolled during the study period (1998-2018) was completed. Primary outcomes evaluated were the 21-day transplant-free survival (TFS) and neurologic complications. Covariates evaluated included enrollment cohort (early, 1998-2007; recent, 2008-2018), intentionality, psychiatric comorbidity, and use of organ support including continuous renal replacement therapy (CRRT).

RESULTS

Of 1190 APAP-ALF patients, recent cohort patients (n = 608) had significantly improved TFS (recent, 69.8% vs early, 61.7%; P = .005). Recent cohort patients were more likely to receive CRRT (22.2% vs 7.6%; P < .001), and less likely to develop intracranial hypertension (29.9% vs 51.5%; P < .001) or die by day 21 from cerebral edema (4.5% vs 11.6%; P < .001). Grouped by TFS status (non-TFS, n = 365 vs TFS, n = 704), there were no differences in psychiatric comorbidity (51.5% vs 55.0%; P = .28) or intentionality (intentional, 39.7% vs 41.6%; P = .58). On multivariable logistic regression adjusting for vasopressor support, development of grade 3/4 hepatic encephalopathy, King's College criteria, and MELD score, the use of CRRT (odds ratio, 1.62; P = .023) was associated with significantly increased TFS (c-statistic, 0.86). In a second model adjusting for the same covariates, recent enrollment was associated significantly with TFS (odds ratio, 1.42; P = .034; c-statistic, 0.86).

CONCLUSIONS

TFS in APAP-ALF has improved in recent years and rates of intracranial hypertension/cerebral edema have decreased, possibly related to increased CRRT use.

Brain Herniation and Intracranial Hypertension

This article introduces the basic concepts of intracranial physiology and pressure dynamics. It also includes discussion of signs and symptoms and examination and radiographic findings of patients with acute cerebral herniation as a result of increased as well as decreased intracranial pressure. Current best practices regarding medical and surgical treatments and approaches to management of intracranial hypertension as well as future directions are reviewed. Lastly, there is discussion of some of the implications of critical medical illness (sepsis, liver failure, and renal failure) and treatments thereof on causation or worsening of cerebral edema, intracranial hypertension, and cerebral herniation.

Therapeutic hypothermia after cardiac arrest during living-donor liver transplant surgery: A case report

RATIONALE

Therapeutic hypothermia is an effective medical treatment for neurological recovery after cardiac arrest. Here, we describe a case of successful mild therapeutic hypothermia after cardiac arrest during living-donor liver transplantation.

PATIENT CONCERNS

A 54-year-old woman with alcoholic liver cirrhosis was admitted for living-donor liver transplantation. Cardiac arrest occurred during the anhepatic phase. After cardiopulmonary resuscitation, spontaneous circulation returned, but the bispectral index level remained below 10 until the end of surgery.

DIAGNOSES

Neurological injury caused by global cerebral hypoperfusion was suspected.

INTERVENTIONS

The patient was treated with mild therapeutic hypothermia for 24hours after resuscitation targeting a core body temperature of 34°C with surface cooling using ice bags.

OUTCOMES

The patient recovered consciousness about 22 hours after the event. However, she showed symptoms of delirium even when discharged. At the 3-month follow-up exam, she showed no specific neurological complications. The transplanted liver showed no problems with regeneration.

LESSONS

Mild therapeutic hypothermia may be safely adopted in cases of cardiac arrest in liver transplant patients and is beneficial for neurological recovery.

Early General Hypothermia Improves Motor Function after Spinal Cord Injury in Rats; a Systematic Review and Meta-Analysis

INTRODUCTION

There is still controversy about the effect of early hypothermia on the outcome of spinal cord injury (SCI). The aim of this review article is to investigate the effect of local or general hypothermia on improving the locomotion after traumatic SCI.

METHODS

Electronic databases (Medline and Embase) were searched from inception until May 7, 2018. Two independent reviewers screened and summarized the relevant experimental studies on hypothermia efficacy in traumatic SCI. The data were analyzed and the findings were presented as pooled standardized mean difference (SMD) and 95% confidence interval (95% CI).

RESULTS

20 papers containing 30 separate experiments were included in meta-analysis. The onset of hypothermia varied between 0 and 240 minutes after SCI. Administration of hypothermia has a positive effect on locomotion following SCI (SMD=0.56 95% CI: 0.18-0.95, p=0.004). Subgroup analysis showed that general hypothermia improves locomotion recovery (SMD =0.89, 95% CI: 0.42 to 1.36; p <0.0001), while local hypothermia does not have a significant effect on motor recovery (SMD=0.20, 95 % CI: -0.36-0.76, p=0.478). In addition, general hypothermia was found to affect motor recovery only if its duration was between 2 and 8 hours (SMD=0.89; p<0.0001) and the target temperature for induction of hypothermia was between 32 and 35° C (SMD=0.83; p<0.0001).

CONCLUSION

We found that general hypothermia improves locomotion after SCI in rats. Duration of induction and the target temperature are two essential considerations for general therapeutic hypothermia.

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.

Current concepts in acute liver failure

Acute liver failure (ALF) is a severe condition secondary to a myriad of causes associated with poor outcomes. The prompt diagnosis and identification of the aetiology allow the administration of specific treatments plus supportive strategies and to define the overall prognosis, the probability of developing complications and the need for liver transplantation. Pivotal issues are adequate monitoring and the institution of prophylactic strategies to reduce the risk of complications, such as progressive liver failure, cerebral oedema, renal failure, coagulopathies or infections. In this article, we review the main aspects of ALF, including the definition, diagnosis and complications. Also, we describe the standard-of-care strategies and recent advances in the treatment of ALF. Finally, we include our experience of care patients with ALF.

Targeted temperature management in acute liver failure: A systematic review

BACKGROUND

Targeted temperature management is the modern term for therapeutic hypothermia, where cooling is induced by intensive care clinicians to achieve body temperatures below 36°C. Its use in acute liver failure to improve refractory intracranial hypertension and patient outcomes is not supported by strong quality evidence.

AIM

This systematic review aims to determine if targeted temperature management improves patient outcome as opposed to normothermia in acute liver failure.

METHODS

A computerized and systematic search of six academic and medical databases was conducted using the following keywords: "acute liver failure", "fulminant hepatic injury", "targeted temperature management", "therapeutic hypothermia", and "cooling". Broad criteria were applied to include all types of primary observational studies, from case reports to randomized controlled trials. Standardized tools were used throughout to critically appraise and extract data.

FINDINGS

Nine studies published between 1999 and 2016 were included. Early observational studies suggest a benefit of targeted temperature management in the treatment of refractory intracranial hypertension and in survival. More recent controlled studies do not show such a benefit in the prevention of intracranial hypertension. All studies revealed that the incidence of coagulopathy is not higher in patients treated with targeted temperature management. There remains some uncertainty regarding the increased risk of infection and dysrhythmias. Heterogeneity was found between study types, design, sample sizes, and quality.

CONCLUSION

Although it does not significantly improve survival, targeted temperature management is efficient in treating episodes of intracranial hypertension and stabilizing an unstable critical care patient without increasing the risk of bleeding. It does not, however, prevent intracranial hypertension. Data heterogeneity may explain the contradictory findings.

RELEVANCE TO CLINICAL PRACTICE

Controlled studies are needed to elucidate the true clinical benefit of targeted temperature management in improving patient outcome.

Induction of selective liver hypothermia prevents significant ischemia/reperfusion injury in Wistar rats after 24 hours

Purpose To investigate the effects of induction of selective liver hypothermia in a rodent model. Methods Seven male Wistar rats were subjected to 90 minutes of partial 70% liver ischemia and topic liver 26°C hypothermia (H group). Other seven male Wistar rats were subjected to 90 minutes of partial 70% normothermic liver ischemia (N group). Five additional rats underwent a midline incision and section of liver ligaments under normothermic conditions and without any liver ischemia (sham group). All animals were sacrificed 24-h after reperfusion, and livers were sampled for analyses. Pathology sections were scored for sinusoidal congestion, ballooning, hepatocelllular necrosis and the presence of neutrophilic infiltrates. Results At the end of the experiment, liver tissue expressions of TNF-ɑ, IL-1β, iNOS and TNF-ɑ/IL-10 ratio were significantly reduced in the H group compared to N group, whereas IL-10 and eNOS were significantly increased in H group. Histopathological injury scores revealed a significant decrease in ischemia/reperfusion (I/R) injuries in H group. Conclusion Selective liver hypothermia prevented I/R injury by inhibiting the release of inflammatory cytokines, preserves microcirculation, prevents hepatocellular necrosis and leukocyte infiltration, allowing maintenance of the liver architecture.

Significant lung injury and its prognostic significance in acute liver failure: A cohort analysis

BACKGROUND AND AIMS

Respiratory failure complicating acute liver failure (ALF) may preclude liver transplantation (LT). We evaluated the association between significant lung injury (SLI) and important clinical outcomes.

METHODS

Retrospective cohort study of 947 ALF patients with chest radiograph (CXR) and arterial blood gas (ABG) data enrolled in the US Acute Liver Failure Study Group (US-ALFSG) from January 1998 to December 2016. SLI was defined by moderate hypoxaemia (Berlin classification; PaO₂ /FiO₂  < 200 mm Hg) and abnormalities on CXR. Primary outcomes were 21-day transplant-free survival (TFS) and overall survival.

RESULTS

Of 947 ALF patients, 370 (39%) had evidence of SLI. ALF patients with SLI (ALF-SLI) had significantly worse oxygenation than controls on admission (median PF ratio 120 vs 300 mm Hg, P < .0001) and higher lactate (6.1 vs 4.6 mmol/l, P = .0008). ALF-SLI patients had higher rates of tracheal (19% vs 14%) and bloodstream (17% vs 11%, P < .005 for both) infections and were more likely to receive transfusions (red cells 55% vs 43%; FFP 74% vs 66%; P < .009 for both). ALF-SLI patients were less likely to receive LT (18% vs 25%, P = .02) and had significantly decreased 21-day TFS (34% vs 42%) and overall survival (49% vs 64%, P < .007 for both). After adjusting for significant covariates (INR, bilirubin, acetaminophen aetiology), the development of SLI was independently associated with decreased 21-day TFS (OR 0.71, P = .03) in ALF patients (C-index 0.78). The incorporation of SLI improved discriminatory ability of the King's College Criteria (P = .0061) but not the ALFSG prognostic index (P = .34).

CONCLUSION

Significant lung injury is a common complication in ALF patients that adversely affects patient outcomes.

Effect of Therapeutic Hypothermia on Liver Enzymes in Patients With Stroke

Introduction:

A promising strategy that can lead to longer brain cell survival after an acute stroke is therapeutic hypothermia. It represents a controlled decrease in body temperature for therapeutic reasons. It is increasingly represented as a therapeutic option and is one of the most challenging treatments that improves neurological recovery and treatment outcome in patients with acute stroke.

Aim:

To examine the effect of therapeutic hypothermia on liver enzymes in patients with diagnosis of stroke.

Methods:

A total of 101 patients diagnosed with acute stroke were treated. The first group (n=40) were treated with conventional treatment and therapeutic hypothermia, while the second group (n=61) only with conventional treatment. Cooling of the body to a target body temperature of 34°C to 35°C was performed for up to 24 hours. Outcome (survival or death) of treatment was monitored, degree of disability was determined by National Institutes of Health Stroke Scale (NIHSS) and assessment of consciousness using the Glasgow Coma Scale (GCS). Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were taken at admission, after 24 hours, and were monitored upon discharge.

Results:

There was a significant difference in AST values at admission relative to disease outcome (p = 0.002), as well as for ALT (p = 0.008). In patients treated with therapeutic hypothermia, mean AST values decreased after 24 hours (32.50 to 31.00 IU/mL) as well as ALT values (27.50 to 26.50 IU/mL), without statistical significance. In the group of subjects who survived with sequela, AST values correlated with GCS (rho = -0.489; p = 0.002) and NIHSS (rho = 0.492; p = 0.003), ALT values correlated with GCS (rho = -0.356; p = 0.03) but not with NIHSS.

Conclusion:

AST and ALT values at admission correlate with the severity of the clinical picture. Therapeutic hypothermia is hepatoprotective and lowers AST and ALT values.

Intensive Care Management of Acute Liver Failure: Considerations While Awaiting Liver Transplantation

Acute liver failure is a unique clinical phenomenon characterized by abrupt deterioration in liver function and altered mentation. The development of high-grade encephalopathy and multisystem organ dysfunction herald poor prognosis. Etiologic-specific treatments and supportive measures are routinely employed; however, liver transplantation remains the only chance for cure in those who do not spontaneously recover. The utility of artificial and bioartificial assist therapies as supportive care-to allow time for hepatic recovery or as a bridge to liver transplantation-has been examined but studies have been small, with mixed results. Given the severity of derangements, intensive critical care is needed to successfully bridge patients to transplant, and evaluation of candidates occurs rapidly in parallel with serial reassessments of operative fitness. Psychosocial assessment is often suboptimal and relative contraindications to transplant, such as ventilator-dependence may be overlooked. While often employed to guide evaluation, no single prognostic model discriminates those who will spontaneously recover and those who will require transplant. The purpose of this review will be to summarize approaches in critical care, prognostic modeling, and medical evaluation of the acute liver failure transplant candidate.

Acute mental change as the presenting sign of posthepatectomy hepatic failure: A case report

RATIONALE

Hepatectomy is a treatment to increase survival and curability of patients with intrahepatic lesions or malignant tumors. However, posthepatectomy liver failure (PHLF) can occur. This case is a patient showing acute mental change in postanesthetic care unit (PACU) as an uncommon symptom of PHLF after extended right hepatectomy.

PATIENT CONCERNS

A 68-year-old male patient was admitted for surgery of Klatskin tumor. He had hypertension and atrial fibrillation. His model for end-stage liver disease score was 16 pts. His serum bilirubin and ammonia levels were 4.75 mg/dL and 132.8 mcg/dL, respectively. Other laboratory data were nonspecific. He underwent extended right hepatic lobectomy including segments IV-VIII for 9 hours. Weight of liver specimen was 1028 g which was about 58% of total liver volume based on computed tomographic volumetry. The patient was extubated and moved to the PACU with stable vital sign and regular self-breathing. He could obey verbal commands. Fifteen minutes after admission to the PACU, the patient showed abruptly decreasing mental status and self-breathing.

DIAGNOSES

Brain computed tomography, blood culture, and sputum culture were performed to diagnose brain lesions and sepsis for evaluating the sudden onset comatous mental status. Results showed nonspecific finding.

INTERVENTIONS

He was intubated for securing airway and applying ventilatory care. The patient was moved to the intensive care unit. He received intensive conservative therapy including continuous renal replacement therapy and broad-spectrum antibiotics.

OUTCOMES

The patient's condition was worsened. He expired on postoperative day 3.

LESSONS

Acute mental change is uncommon and rare as initial symptoms of PHLF. Therefore, clinician may overlook the diagnosis of PHLF in patients with acute mental change after hepatectomy. Thus, clinician should plan an aggressive treatment for PHLF including liver transplantation by recognizing any suspicious symptom, although such symptom is rare.

A case of chronic hepatitis B merged with acute fatty liver of pregnancy with severe coagulopathy

Background

Acute fatty liver of pregnancy (AFLP) is a life-threatening disorder, and its relevance to viral hepatitis B (HB) remains unknown. This case presents an initial experience of treating a patient with HB progressing to AFLP throughout pregnancy; anesthesiologists should also recognize its clinical feature for perioperative management.

Case presentation

A 28-year-old parturient was diagnosed as chronic HB (CHB) at 21 weeks gestation. Liver and kidney dysfunction appeared rapidly at 34 weeks gestation, suspected as acute exacerbation of either CHB or AFLP. Emergency cesarean section was carried out, after which maternal disseminated intravascular coagulation and hypothermia persisted. With multidisciplinary management, the patient and infant were discharged on postpartum days 64 and 12, respectively.

Conclusions

Active CHB develops into AFLP. Antiviral therapy should be considered for parturient patients with CHB, particularly for those with high viral load. The most favorable outcome is prompt and accurate diagnosis to establish suitable termination method.

Neurological Monitoring in Acute Liver Failure

Cerebral oedema and Intracranial Hypertension (ICH) are serious complications of acute liver failure affecting approximately 30% of patients, resulting in neurological injury or death. Multiple pathogenetic mechanisms contribute to the pathogenesis of HE including circulating neurotoxins such as ammonia, systemic and neuro-inflammation, infection and cerebral hyperaemia due to loss of cerebral vascular autoregulation. Early recognition and diagnosis is often difficult as clinical signs of elevated Intracranial Pressure (ICP) are not uniformly present and maybe masked by other organ support. ICP monitoring provides early diagnosis and monitoring of ICH, allowing targeted therapeutic interventions for prevention and treatment. ICP monitoring is the subject of much debate and there exists significant heterogeneity of clinical practice regarding its use. The procedure is associated with risks of haemorrhage but may be considered in highly selected patients such as those with highest risk for ICH awaiting transplant to allow for patient selection and optimisation. There is limited evidence that ICP monitoring confers a survival benefit which may explain why in the context of risk benefit analysis there is reduced utilisation in clinical practice. Less or non-invasive techniques of neurological monitoring such as measurement of jugular venous oxygen saturation to assess cerebral oxygen utilisation, and transcranial Doppler CNS to measure cerebral blood flow can provide important clinical information. They should be considered in combination as part of a multi-modal platform utilising specific roles of each system and incorporated within locally agreed algorithms. Other tools such as near-infrared spectrophotometry, optic nerve ultrasound and serum biomarkers of brain injury are being evaluated but are not used routinely in current practice.

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.

Targeted Temperature Management in Brain Injured Patients

Evidence from animal models indicates that lowering temperature by a few degrees can produce substantial neuroprotection. In humans, hypothermia has been found to be neuroprotective with a significant impact on mortality and long-term functional outcome only in cardiac arrest and neonatal hypoxic-ischemic encephalopathy. Clinical trials have explored the potential role of maintaining normothermia and treating fever in critically ill brain injured patients. This review concentrates on basic concepts to understand the physiologic interactions of thermoregulation, effects of thermal modulation in critically ill patients, proposed mechanisms of action of temperature modulation, and practical aspects of targeted temperature management.

Targeted Temperature Management in Brain Injured Patients

Evidence from animal models indicates that lowering temperature by a few degrees can produce substantial neuroprotection. In humans, hypothermia has been found to be neuroprotective with a significant impact on mortality and long-term functional outcome only in cardiac arrest and neonatal hypoxic-ischemic encephalopathy. Clinical trials have explored the potential role of maintaining normothermia and treating fever in critically ill brain injured patients. This review concentrates on basic concepts to understand the physiologic interactions of thermoregulation, effects of thermal modulation in critically ill patients, proposed mechanisms of action of temperature modulation, and practical aspects of targeted temperature management.

Modern Management of Acute Liver Failure

Acute liver failure is a rare but life-threatening disease that can lead to progressive encephalopathy, intracranial hypertension, and multiorgan failure. In the developed world, the most common cause remains acetaminophen overdose, but there are still many cases in which there is acute liver failure of unknown etiology. The mainstay of acute liver failure management remains supportive care in the critical care setting. If supportive treatment does not stabilize the disease process, the patient may require emergent liver transplantation. This article summarizes the current management of acute liver failure.

Brain and the Liver: Cerebral Edema, Hepatic Encephalopathy and Beyond

Occurrence of brain dysfunction is common in both chronic liver disease as well as acute liver failure. While brain dysfunction most commonly manifests as hepatic encephalopathy is chronic liver disease; devastating complications of cerebral edema and brain herniation syndromes may occur with acute liver failure. Ammonia seems to play a central role in the pathogenesis of brain dysfunction in both chronic liver disease and acute liver failure. In this chapter we outline the pathophysiology and clinical management of brain dysfunction in the critically ill patients with liver disease.

Acute Liver Failure

Acute liver failure (ALF) is a life-threatening condition of heterogeneous etiology. Outcomes are better with early recognition and prompt initiation of etiology-specific therapy, intensive care protocols, and liver transplantation (LT). Prognostic scoring systems include the King's College Criteria and Model for End-stage Liver Disease score. Cerebral edema and intracranial hypertension are reasons for high morbidity and mortality; hypertonic saline is suggested for patients with a high risk for developing intracranial hypertension, and when it does, mannitol is recommended as first-line therapy. Extracorporeal liver support system may serve as a bridge to LT and may increase LT-free survival in select cases.

Outcome of in- and out-of-hospital cardiac arrest survivors with liver cirrhosis

Background

Organ failure increases mortality in patients with liver cirrhosis. Data about resuscitated cardiac arrest patients with liver cirrhosis are missing. This study aims to assess aetiology, survival and functional outcome in patients after successful cardiopulmonary resuscitation (CPR) with and without liver cirrhosis.

Methods

Analysis of prospectively collected cardiac arrest registry data of consecutively hospital-admitted patients following successful CPR was performed. Patient’s characteristics, admission diagnosis, severity of disease, course of disease, short- and long-term mortality as well as functional outcome were assessed and compared between patients with and without cirrhosis.

Results

Out of 1068 patients with successful CPR, 47 (4%) had liver cirrhosis. Acute-on-chronic liver failure (ACLF) was present in 33 (70%) of these patients on admission, and four patients developed ACLF during follow-up. Mortality at 1 year was more than threefold increased in patients with liver cirrhosis (OR 3.25; 95% CI 1.33–7.96). Liver cirrhosis was associated with impaired neurological outcome (OR for a favourable cerebral performance category: 0.13; 95% CI 0.04–0.36). None of the patients with Child–Turcotte–Pugh (CTP) C cirrhosis survived 28 days with good neurological outcome. Overall nine (19%) patients with cirrhosis survived 28 days with good neurological outcome. All patients with ACLF grade 3 died within 28 days.

Conclusion

Cardiac arrest survivors with cirrhosis have worse outcome than those without. Although one quarter of patients with liver cirrhosis survived longer than 28 days after successful CPR, patients with CTP C as well as advanced ACLF did not survive 28 days with good neurological outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0322-1) contains supplementary material, which is available to authorized users.

Hepatic Encephalopathy-the Old and the New

Hepatic encephalopathy occurs ubiquitously in all causes of advanced liver failure, however, its implications on mortality diverge and vary depending upon acuity and severity of liver failure. This associated mortality has decreased in subsets of liver failure over the last 20 years. Aside from liver transplantation, this improvement is not attributable to a single intervention but likely to a combination of practical advances in critical care management. Misconceptions surrounding many facets of hepatic encephalopathy exists due to heterogeneity in presentation, pathophysiology and outcome. This review is intended to highlight the important concepts, rationales and strategies for managing hepatic encephalopathy.

Intensive Care Management of Pediatric Acute Liver Failure

Pediatric acute liver failure is rare but life-threatening illness that occurs in children without preexisting liver disease. The rarity of the disease, along with its severity and heterogeneity, presents unique clinical challenges to the physicians providing care for pediatric patients with acute liver failure. In this review, practical clinical approaches to the care of critically ill children with acute liver failure are discussed with an organ system-specific approach. The underlying pathophysiological processes, major areas of uncertainty, and approaches to the critical care management of pediatric acute liver failure are also reviewed.

Acute Liver Failure

Acute liver failure, also known as fulminant hepatic failure, is a rare life-threatening disease that has a high mortality rate and affects many organ systems. Causes of acute liver failure vary-it can be attributed to drugs, viruses, and other uncommon sources. Complications of liver failure can include encephalopathy, cerebral edema, sepsis, renal failure, gastrointestinal bleeding, and respiratory failure. Fortunately, with advances in critical care medicine and emergent liver transplant, mortality rates have decreased in the past decade. This article reviews acute liver failure, its manifestations in different organ systems, and its treatment.

Drug-Induced Acute Liver Failure

Drug-induced acute liver failure (ALF) disproportionately affects women and nonwhites. It is most frequently caused by antimicrobials and to a lesser extent by complementary and alternative medications, antiepileptics, antimetabolites, nonsteroidals, and statins. Most drug-induced liver injury ALF patients have hepatocellular injury pattern. Cerebral edema and intracranial hypertension are the most serious complications of ALF. Other complications include coagulopathy, sepsis, metabolic derangements, and renal, circulatory, and respiratory dysfunction. Although advances in intensive care have improved outcome, ALF has significant mortality without liver transplantation. Liver-assist devices may provide a bridge to transplant or to spontaneous recovery.

Acute liver failure: An up-to-date approach

Acute liver failure is a rare but potentially devastating disease. Throughout the last few decades, acute liver failure outcomes have been improving in the context of the optimized overall management. This positive trend has been associated with the earlier recognition of this condition, the improvement of the intensive care unit management, and the developments in emergent liver transplantation. Accordingly, we aimed to review the current diagnostic and therapeutic approach to this syndrome, especially in the intensive care unit setting.

Spectral Electroencephalogram Analysis for the Evaluation of Encephalopathy Grade in Children With Acute Liver Failure

OBJECTIVE

Spectral electroencephalogram analysis is a method for automated analysis of electroencephalogram patterns, which can be performed at the bedside. We sought to determine the utility of spectral electroencephalogram for grading hepatic encephalopathy in children with acute liver failure.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care pediatric hospital.

PATIENTS

Patients between 0 and 18 years old who presented with acute liver failure and were admitted to the PICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Electroencephalograms were analyzed by spectral analysis including total power, relative δ, relative θ, relative α, relative β, θ-to-Δ ratio, and α-to-Δ ratio. Normal values and ranges were first derived using normal electroencephalograms from 70 children of 0-18 years old. Age had a significant effect on each variable measured (p < 0.03). Electroencephalograms from 33 patients with acute liver failure were available for spectral analysis. The median age was 4.3 years, 14 of 33 were male, and the majority had an indeterminate etiology of acute liver failure. Neuroimaging was performed in 26 cases and was normal in 20 cases (77%). The majority (64%) survived, and 82% had a good outcome with a score of 1-3 on the Pediatric Glasgow Outcome Scale-Extended at the time of discharge. Hepatic encephalopathy grade correlated with the qualitative visual electroencephalogram scores assigned by blinded neurophysiologists (rs = 0.493; p < 0.006). Spectral electroencephalogram characteristics varied significantly with the qualitative electroencephalogram classification (p < 0.05). Spectral electroencephalogram variables including relative Δ, relative θ, relative α, θ-to-Δ ratio, and α-to-Δ ratio all significantly varied with the qualitative electroencephalogram (p < 0.025). Moderate to severe hepatic encephalopathy was correlated with a total power of less than or equal to 50% of normal for children 0-3 years old, and with a relative θ of less than or equal to 50% normal for children more than 3 years old (p > 0.05). Spectral electroencephalogram classification correlated with outcome (p < 0.05).

CONCLUSIONS

Spectral electroencephalogram analysis can be used to evaluate even young patients for hepatic encephalopathy and correlates with outcome. Spectral electroencephalogram may allow improved quantitative and reproducible assessment of hepatic encephalopathy grade in children with acute liver failure.

Emerging strategies for the treatment of patients with acute hepatic failure

PURPOSE OF REVIEW

The objective of this article is to review the latest developments related to the treatment of patients with acute liver failure (ALF).

RECENT FINDINGS

As the treatment of ALF has evolved, there is an increasing recognition regarding the risk of intracranial hypertension related to advanced hepatic encephalopathy. Therefore, there is an enhanced emphasis on neuromonitoring and therapies targeting intracranial hypertension. Also, new evidence implicates systemic proinflammatory cytokines as an etiology for the development of multiorgan system dysfunction in ALF; the recent finding of a survival benefit in ALF with high-volume plasmapheresis further supports this theory.

SUMMARY

Advances in the critical care management of ALF have translated to a substantial decrease in mortality related to this disease process. The extrapolation of therapies from general neurocritical care to the treatment of ALF-induced intracranial hypertension has resulted in improved neurologic outcomes. In addition, recognition of the systemic inflammatory response and multiorgan dysfunction in ALF has guided current treatment recommendations, and will provide avenues for future research endeavors. With respect to extracorporeal liver support systems, further randomized studies are required to assess their efficacy in ALF, with attention to nonsurvival end points such as bridging to liver transplantation.

A multicentre randomized controlled trial of moderate hypothermia to prevent intracranial hypertension in acute liver failure

BACKGROUND & AIMS

Animal models and human case series of acute liver failure (ALF) suggest moderate hypothermia (MH) to have protective effects against cerebral oedema (CO) development and intracranial hypertension (ICH). However, the optimum temperature for patient management is unknown. In a prospective randomized controlled trial we investigated if maintenance of MH prevented development of ICH in ALF patients at high risk of the complication.

METHODS

Patients with ALF, high-grade encephalopathy and intracranial pressure (ICP) monitoring in specialist intensive care units were randomized by sealed envelope to targeted temperature management (TTM) groups of 34°C (MH) or 36°C (control) for a period of 72h. Investigators were not blinded to group assignment. The primary outcome was a sustained elevation in ICP >25mmHg, with secondary outcomes the occurrence of predefined serious adverse effects, magnitude of ICP elevations and cerebral and all-cause hospital mortality (with or without transplantation).

RESULTS

Forty-six patients were randomized, of whom forty-three were studied. There was no significant difference between the TTM groups in the primary outcome during the study period (35% vs. 27%, p=0.56), for the MH (n=17) or control (n=26) groups respectively, relative risk 1.31 (95% CI 0.53-3.2). Groups had similar incidence of adverse events and overall mortality (41% vs. 46%, p=0.75).

CONCLUSIONS

In patients with ALF at high risk of ICH, MH at 33-34°C did not confer a benefit above management at 36°C in prevention of ICH or in overall survival. This study did not confirm advantage of its prophylactic use. (ISRCTN registration number 74268282; no funding.)

LAY SUMMARY

Studies in animals with acute liver failure (ALF) have suggested that cooling (hypothermia) could prevent or limit the development of brain swelling, a dangerous complication of the condition. There is limited data on its effects in humans. In a randomized controlled trial in severely ill patients with ALF we compared the effects of different temperatures and found no benefit on improving survival or preventing brain swelling by controlling temperature at 33-34°C against 36°C.

Potential targeted therapies for the inflammatory pathogenesis of hepatic encephalopathy

Hepatic encephalopathy (HE) is a severe neuropsychiatric complication of acute and chronic liver dysfunction, and is characterized by a spectrum that ranges from mild neuropsychological disturbances to coma. Although ammonia plays a critical role in the pathogenesis of HE, the plasma concentrations of ammonia and manifest symptoms of HE are not always consistent in patients with HE. Recently, a substantial body of evidence has indicated that inflammation acts in concert with ammonia in the pathogenesis of HE. Meanwhile, emerging novel and potential therapeutic strategies, including N-acetylcysteine, hypothermia, minocycline, non-steroidal anti-inflammatory drugs, tumour necrosis factor-alpha antagonists and p38 inhibitors, have been reported to ameliorate systemic inflammation and neuroinflammation, improve or reverse neuropsychiatric manifestations, and prevent the onset and progression of HE in patients and/or animal models of acute or chronic liver failure. These results point to the possible therapeutic utility of decreasing inflammation in the treatment of HE, and translation of these experimental results to the clinic may provide novel and promising therapeutic approaches for patients with HE secondary to acute or chronic liver failure. This review will provide an overview of these potential targeted therapies in the prophylaxis and treatment of HE.

What a Nephrologist Needs to Know About Acute Liver Failure

Although relatively rare in the United States, acute liver failure (ALF) is associated with very high rates of morbidity and mortality. A leading cause of morbidity and mortality is cerebral edema and intracranial hypertension. Hypothermia, osmotic diuretics, and hyperosmolar therapy are commonly used to manage these complications; however, when these are ineffective, renal replacement therapy may be needed for volume management. Acute kidney injury is a common complication of ALF and may arise from a number of etiologies, including hepatorenal syndrome and acute tubular necrosis. Acute kidney injury is most common in patients who develop ALF because of acetaminophen toxicity or ischemia. With regard to renal replacement therapy, we will review specific considerations relevant to the management of the patient with ALF.

Current management of acute liver failure

PURPOSE OF REVIEW

Acute liver failure (ALF) is a rare but life-threatening systemic disorder. Survival rates with or without emergency liver transplantation (ELT) are increasing. The benefit of ELT in some cases has been questioned and the potential for survival with medical management alone is changing our approach to the management of this disease.

RECENT FINDINGS

Survival rates for all causes of ALF are increasing because of improvements in the care of the critically ill patient. A multifactorial approach involving support of respiratory, circulatory and renal function together with measures to avoid intracranial hypertension, metabolic disequilibrium and sepsis are required. For those who do not respond to these measures or specific antidotes, the selection methods for those likely to benefit from transplantation remain imperfect and novel methods based on the prediction of hepatic regeneration are required. For patients with ALF secondary to acetaminophen overdose, some experts believe a randomized controlled trial is required to find those most likely to benefit from ELT.

SUMMARY

ALF remains a life-threatening condition with a high mortality rate requiring prompt support of multiorgan failure. Historical listing criteria for ELT are being questioned and improvement in medical management offers the option of continued improvements in transplant-free survival.

Acute liver failure: A curable disease by 2024?

Over the last three decades acute liver failure (ALF) has been transformed from a rare and poorly understood condition with a near universally fatal outcome, to one with a well characterized phenotype and disease course. Complex critical care protocols are now applied and emergency liver transplantation (ELT) is an established treatment option. These improvements in care are such that the majority of patients may now be expected to survive (Fig. 1). Key features of the condition have changed dramatically over time, with a remarkable fall in the incidence of cerebral edema and intracranial hypertension, a much feared complication. In this review, we summarize the current understanding of key aspects of the classification, pathophysiology and management of ALF, and discuss the foreseeable challenges that will need to be addressed for further improvements to be achieved.