Acute Liver Failure(ALF)

Acute liver failure is a rare and life-threatening condition where the liver rapidly loses its function, typically within days or weeks, in a person without pre-existing liver disease. It's a medical emergency requiring immediate hospitalization, often in the intensive care unit, and evaluation at a liver transplant center.

Causes:

The most common causes vary geographically, but in developed countries, they include:

• Acetaminophen overdose: This is the leading cause in the United States. It can occur from a single large dose or from taking higher than recommended doses over several days, sometimes unintentionally when combined with other medications containing acetaminophen.
• Viral hepatitis: Hepatitis A, B, and E are significant causes worldwide. Other viruses like Epstein-Barr virus, cytomegalovirus, and herpes simplex virus can also lead to acute liver failure.
• Drug-induced liver injury (DILI): Many prescription medications (like certain antibiotics, NSAIDs, and anticonvulsants) and herbal supplements can cause acute liver failure.
• Toxins: The poisonous Amanita phalloides ("death cap") mushroom is a well-known cause. Industrial chemicals like carbon tetrachloride can also be culprits.
• Autoimmune hepatitis: The body's immune system mistakenly attacks liver cells.
• Vascular diseases of the liver: Conditions like Budd-Chiari syndrome (blockage of liver veins) can lead to acute liver failure.
• Metabolic diseases: Rare inherited conditions like Wilson's disease and acute fatty liver of pregnancy can sometimes cause it.
• Cancer: Cancer that starts in or spreads to the liver can cause failure.
• Shock: Severe infection (sepsis) and shock can reduce blood flow to the liver, leading to failure.
• Heatstroke: Extreme physical activity in hot environments can trigger it.
• Unknown causes: In some cases, the cause cannot be identified.

Symptoms:

Early symptoms can be non-specific and may include:

• Fatigue
• Nausea
• Vomiting
• Loss of appetite
• Right upper quadrant abdominal pain

As the condition progresses, more severe symptoms develop:

• Jaundice: Yellowing of the skin and whites of the eyes.
• Mental changes (encephalopathy): Confusion, disorientation, drowsiness, irritability, and eventually coma.
• Easy bruising and bleeding (coagulopathy): The liver produces clotting factors, and its failure leads to impaired blood clotting.
• Swelling (edema): Fluid buildup in the abdomen (ascites) and legs.

Diagnosis:

Diagnosis involves a thorough medical history, physical examination, and various tests, including:

• Blood tests: To assess liver function, coagulation, and identify potential causes (e.g., viral hepatitis markers, drug levels).
• Imaging studies: Ultrasound is often used to visualize the liver. Other imaging like CT or MRI may be necessary.
• Liver biopsy: A small sample of liver tissue is taken for examination, especially when the cause is unclear. A transjugular biopsy may be performed to minimize bleeding risk.

Treatment:

Treatment depends on the underlying cause and the severity of liver failure. It often involves supportive care in the ICU and specific therapies:

• Reversing the cause:
  • N-acetylcysteine (NAC): For acetaminophen overdose, given as soon as possible, ideally within hours of the overdose. It can also sometimes help with acute liver failure from other causes.
  • Antiviral medications: For viral hepatitis.
  • Medications to reverse poisoning: For certain toxins, like specific treatments for mushroom poisoning.
  • Immunosuppressants: For autoimmune hepatitis.
• Supportive care:
  • Managing complications: Addressing brain swelling (cerebral edema), bleeding, infections, and electrolyte imbalances.
  • Nutritional support: Providing nutrients if the patient cannot eat.
  • Monitoring: Frequent blood tests and close observation for any deterioration.
• Liver transplant: This is often the only life-saving treatment when the liver cannot recover on its own. Patients are evaluated for transplant eligibility and placed on a waiting list.

Prognosis:

The outcome of acute liver failure varies significantly depending on the cause, the severity of the condition, and how quickly treatment is initiated. Some individuals may recover with medical management, while others require a liver transplant. Early recognition and referral to a specialist center are crucial for improving the chances of survival.

Author

Paddy Kalish OD, JD and B.Arch