Acute Liver Failure - Dr. Yomal Amarathunge

Introduction

Acute hepatic failure is a severe and potentially reversible liver injury that occurs in individuals without pre-existing liver disease. It is characterized by the rapid onset of liver dysfunction and hepatic encephalopathy within four weeks of the onset of symptoms.

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Aetiology

Acute liver failure is caused by various factors,

  • including viral hepatitis (such as hepatitis A, B, and E, and occasionally dengue),
  • drug-induced liver injury (often due to paracetamol overdose and excessive alcohol consumption),
  • vascular disorders (rarely hepatic vein thrombosis),
  • autoimmune hepatitis, and
  • ischemic hepatitis.

Pathogenesis

Acute liver failure occurs when a significant portion of hepatocytes fails to function due to injury or necrosis within a short period. This results in hepatic encephalopathy and compromised liver functions such as synthesis, metabolism, and excretion. Consequently, patients may develop coagulopathy, hypoglycemia, and jaundice. Other investigations, such as high serum ammonia levels and abnormal coagulation profiles, aid in the diagnosis of acute hepatic failure.

Clinical Manifestations

Patients with acute hepatic failure typically present with

  • deep jaundice and
  • signs of hepatic encephalopathy.

They may experience multiple complications, including cardiorespiratory compromise, renal dysfunction, and coagulopathy with disseminated intravascular coagulation (DIC). However, in cases of paracetamol overdose, minimal jaundice may be observed.

Investigations

Diagnostic investigations for acute hepatic failure focus on detecting

  • Evidence of hepatocyte injury or necrosis,
  • Identifying complications, and
  • Determining the underlying cause.

Key investigations include

  • elevated levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT),
  • elevated serum bilirubin (direct and indirect),
  • neutrophil leukocytosis,
  • thrombocytopenia,
  • prolonged prothrombin time,
  • hepatitis serology (specifically for hepatitis A and B), and
  • measurement of paracetamol levels.

Additional tests may include serum ammonia levels, coagulation profile (activated partial thromboplastin time, prothrombin time/international normalized ratio), and renal function tests (serum creatinine).

acute liver failure investgations

Management of Acute Liver Failure

Managing acute hepatic failure involves general supportive measures and specific interventions based on the underlying cause.

General Management

  • Patients with acute hepatic failure should ideally receive intensive care or high dependency unit (HDU) support.
  • It is crucial to maintain adequate oxygenation and hemodynamic stability, protect the airway, and ensure proper ventilation for patients with encephalopathy.
  • Intravenous fluids and vasopressors may be administered to stabilize blood pressure, while continuous blood glucose monitoring is necessary to prevent hypoglycemia.
  • Nutritional support through nasogastric (NG) feeding is essential, along with the administration of broad-spectrum antibiotics to address potential infections.

Management of Complications

Hepatic encephalopathy can be treated with lactulose, which reduces bacterial load and ammonia production in the gut. Oral antibiotics like metronidazole or rifaximin may also be used to reduce bacterial load.

In cases of increased intracranial pressure, patients may be propped up to 30 degrees and receive hypertonic saline or mannitol under supervision.

Renal dysfunction requires careful monitoring of fluid balance, and renal replacement therapy may be necessary.

Coagulopathy, if accompanied by bleeding or invasive procedures, can be managed with fresh frozen plasma (FFP) and platelet transfusions.

Definitive Therapy

In cases of paracetamol overdose, N-acetylcysteine (NAC) is the primary definitive therapy. NAC may also have a role in the treatment of non-paracetamol-induced acute liver injury. Liver transplantation is another option for patients with acute liver injury.

Summary

Acute hepatic failure is a severe condition characterized by rapid liver dysfunction and hepatic encephalopathy. Prompt recognition, appropriate investigations, and early management are crucial for improving patient outcomes. Understanding the causes and implementing specific interventions based on the underlying aetiology is vital in treating acute hepatic failure.

By Dr. Yomal Amarathunge

Dr. Yomal Amarathunge is a young and promising doctor who is making a difference in the world of medicine. He graduated from the University of Kelaniya in Sri Lanka, where he earned his Bachelor of Medicine, Bachelor of Surgery (MBBS) degree. In addition to his work as a doctor, Dr. Amarathunge is also a software developer. He is the creator of DewMal’s Health Blog, a website that provides information on health and wellness to the people of Sri Lanka. He is also the developer of DewMal’s Health App, a mobile app that provides users with access to health information and resources.

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