Structured approach to treat patients with acute liver failure: A hepatic emergency

Liver transplantation in acute liver failure: Dilemmas and challenges

Acute liver failure (ALF) refers to a state of severe hepatic injury that leads to altered coagulation and sensorium in the absence of pre-existing liver disease. ALF has different causes, but the clinical characteristics are strikingly similar. In clinical practice, however, inconsistency in the definition of ALF worldwide and confusion regarding the existence of pre-existing liver disease raise diagnostic dilemmas. ALF mortality rates used to be over 80% in the past; however, survival rates on medical treatment have significantly improved in recent years due to a greater understanding of pathophysiology and advances in critical care management. The survival rates in acetaminophen-associated ALF have become close to the post-transplant survival rates. Given that liver transplantation (LT) is an expensive treatment that involves a major surgical operation in critically ill patients and lifelong immunosuppression, it is very important to select accurate patients who may benefit from it. Still, emergency LT remains a lifesaving procedure for many ALF patients. However, there is a lack of consistency in current prognostic models that hampers the selection of transplant candidates in a timely and precise manner. The other problems associated with LT in ALF are the shortage of graft, development of contraindications on the waiting list, vaguely defined delisting criteria, time constraints for pre-transplant evaluation, ethical concerns, and comparatively poor post-transplant outcomes in ALF. Therefore, there is a desperate need to establish accurate prognostic models and explore the roles of evolving adjunctive and alternative therapies, such as liver support systems, plasma exchange, stem cells, auxiliary LT, and so on, to enhance transplant-free survival and to fill the void created by the graft shortage

Hypertonic saline solution decreases oxidative stress in liver hypothermic ischemia

BACKGROUND

Liver ischemia reperfusion injury is still an unsolved problem in liver surgery and transplantation. In this setting, hypothermia is the gold standard method for liver preservation for transplantation. Hypertonic saline solution reduces inflammatory response with better hemodynamic recovery in several situations involving ischemia reperfusion injury. Here, we investigated the effect of hypertonic saline solution in hypothermic liver submitted to ischemia reperfusion injury.

METHODS

Fifty male rats were divided into 5 groups: SHAM, WI (animals submitted to 40 minutes of partial warm liver ischemia and reperfusion), HI (animals submitted to 40 minutes hypothermic ischemia), HSPI (animals submitted to hypothermic ischemia and treated with 7.5% hypertonic saline solution preischemia), and HSPR (animals submitted to hypothermic ischemia and treated with hypertonic saline solution previously to liver reperfusion). Four hours after reperfusion, the animals were euthanized to collect liver and blood samples.

RESULTS

Aspartate aminotransferase and alanine aminotransferase, histologic score, and hepatocellular necrosis were significantly decreased in animals submitted to hypothermia compared with the warm ischemia group. Malondialdehyde was significantly decreased in hypothermic groups with a further decrease when hypertonic saline solution was administrated preischemia. Hypothermic groups also showed decreased interleukin-6, interleukin-10, and tumor necrosis factor-α concentrations and better recovery of bicarbonate, base excess, lactate, and glucose blood concentrations. Moreover, hypertonic saline solution preischemia was more effective at controlling serum potassium concentrations.

CONCLUSION

Hypertonic saline solution before hypothermic hepatic ischemia decreases hepatocellular oxidative stress, cytokine concentrations, and promotes better recovery of acid-base disorders secondary to liver ischemia reperfusion.

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.

Mesenchymal stem cells prolong survival and prevent lethal complications in a porcine model of fulminant liver failure

BACKGROUND

Fulminant liver failure (FLF) is a life-threatening disease.

METHODS

Lethal FLF was induced by ischemia-reperfusion (I-R) injury in mini-pigs, and MSCs were infused via splenic vein after reperfusion.

RESULTS

Accumulated survival within 28 days was significantly improved by MSCs (P = 0.0348). Notably, MSCs maintained blood-gas homeostasis in the first 24 hours and prevented FLF-induced elevation of prothrombin time, international normalized ratio, and creatinine and ammonia levels in the first 3 days. With MSCs, serum levels of liver enzymes gradually decreased after 3 days, and platelet count was back to normal at 1 week of FLF. MSCs promoted liver regeneration within 2 weeks and differentiated into functional hepatocytes at 2-4 weeks after transplantation, evidenced by increase in Ki67-positive cells, detectable human hepatocyte growth factor, human vascular endothelial growth factor, human hepatocyte-specific antigen, and human albumin-expressing cells in the liver at different time points. Reactive oxidative species (ROS) were accumulated after FLF and eliminated at 4 weeks after MSC transplantation.

CONCLUSIONS

Together, MSCs prolong the survival and prevent lethal sequelae of I-R injury-induced FLF by maintenance of liver-function homeostasis and rescue of ROS in the acute stage and by homing and differentiation into hepatocytes in the subacute stage.

The Misunderstood Coagulopathy of Liver Disease: A Review for the Acute Setting

The international normalized ratio (INR) represents a clinical tool to assess the effectiveness of vitamin-K antagonist therapy. However, it is often used in the acute setting to assess the degree of coagulopathy in patients with hepatic cirrhosis or acute liver failure. This often influences therapeutic decisions about invasive procedures or the need for potentially harmful and unnecessary transfusions of blood product. This may not represent a best-practice or evidence-based approach to patient care. The author performed a review of the literature related to the utility of INR in cirrhotic patients using several scientific search engines. Despite the commonly accepted dogma that an elevated INR in a cirrhotic patient corresponds with an increased hemorrhagic risk during the performance of invasive procedures, the literature does not support this belief. Furthermore, the need for blood-product transfusion prior to an invasive intervention is not supported by the literature, as this practice increases the risk of complications associated with a patient's hospital course. Many publications ranging from case studies to meta-analyses refute this evidence and provide examples of thrombotic events despite elevated INR values. Alternative methods, such as thromboelastogram, represent alternate means of assessing in vivo risk of hemorrhage in patients with acute or chronic liver disease in real-time in the acute setting.

Perioperative monitoring of intracranial pressure using optic nerve sheath diameter in paediatric liver transplantation

An elevation of intracranial pressure (ICP) secondary to cerebral oedema is a major contributor to morbidity and mortality in acute liver failure (ALF). We present a case of ICP monitoring with ocular ultrasonography in a 2-year-old child with ALF for liver transplantation. Since invasive ICP monitoring was risky considering the level of coagulopathy, optic nerve sheath diameter (ONSD) monitoring was done by ultrasound. A value of 4.5 mm was chosen as the cut-off for an ICP >20 mmHg in this child and was checked at regular intervals during the surgery. Ultrasonographic ONSD assessment can be a useful modality in liver transplant recipients, with severe coagulopathy and high ICP. In our specific patient scenario, ocular ultrasound proved to be a valuable safe and noninvasive monitoring tool in this paediatric patient.

Association Between Dyspnea and Severity of Liver Disease in Patients in the Pre-transplantation Period-A Pilot Study

BACKGROUND

Liver transplantation is indicated at the end stage of chronic liver failure, and severity of disease will determine the precocity of this happening. At this stage, the presence of chronic dyspnea is one of several manifestations of progression of the disease, which leads the patient to inactivity. A rehabilitation program can positively influence the evolution of liver transplant recipients. The objective of this study was to establish an association between the perception of dyspnea and the severity of liver disease in patients at a single center of a Brazilian liver pre-transplantation clinic.

METHODS

Measurements were performed at a liver pre-transplantation clinic. The severity of liver disease was assessed with the use of the Model for End-Stage Liver Disease (MELD) score, and dyspnea was assessed with the use of a modified Medical Research Council scale of dyspnea (mMRC).

RESULTS

Men had a higher prevalence of viral hepatitis. Dyspnea was reported only during intense exercise. Duration of disease and MELD score showed medians of 49 months and 20, respectively.

CONCLUSIONS

We found no correlation between mMRC and the MELD score. In addition, no correlation was found between duration of disease and MELD score or mMRC.

Acute liver failure in dogs and cats

OBJECTIVE

To define acute liver failure (ALF), review the human and veterinary literature, and discuss the etiologies and current concepts in diagnostic and treatment options for ALF in veterinary and human medicine.

ETIOLOGY

In veterinary medicine ALF is most commonly caused by hepatotoxin exposure, infectious agents, inflammatory diseases, trauma, and hypoxic injury.

DIAGNOSIS

A patient may be deemed to be in ALF when there is a progression of acute liver injury with no known previous hepatic disease, the development of hepatic encephalopathy of any grade that occurs within 8 weeks after the onset of hyperbilirubinemia (defined as plasma bilirubin >50 μM/L [>2.9 mg/dL]), and the presence of a coagulopathy. Diagnostic testing to more specifically characterize liver dysfunction or pathology is usually required.

THERAPY

Supportive care to aid the failing liver and compensate for the lost functions of the liver remains the cornerstone of care of patients with ALF. Advanced therapeutic options such as extracorporeal liver assist devices and transplantation are currently available in human medicine.

PROGNOSIS

The prognosis for ALF depends upon the etiology, the degree of liver damage, and the response to therapy. In veterinary medicine, the prognosis is generally poor.

Update in intensive care medicine: acute liver failure. Initial management, supportive treatment and who to transplant

PURPOSE OF REVIEW

Acute liver failure (ALF) is associated with significant mortality. Although specific therapies may be available, the evidence base for these and for many aspects of supportive therapy has been slow to emerge. Liver transplantation continues to be a cornerstone of treatment, and the management of ALF, therefore, remains the domain of the specialist ICU. The purpose of this review is to identify and critically appraise the recent evidence and to inspire those who strive to provide excellent care for a difficult patient cohort.

RECENT FINDINGS

Effective vaccination programmes have reduced the incidence of viral hepatitis in Europe and the USA. Spontaneous survival has improved in causes such as acetaminophen toxicity. Early recognition and proactive intensive management have reduced the incidence of early neurological death. The use of artificial liver assist devices and therapeutic plasma exchange is controversial, yet intriguing, with some early evidence of efficacy.

SUMMARY

Increasingly sophisticated prognostication tools are evolving, which have the potential to transform clinical decision-making. A review of the indications for transplantation in acetaminophen toxicity is overdue. The use of therapeutic plasma exchange and extracorporeal liver support in ALF requires further investigation.