Liver Failure (Acute)

Causes

The liverAcute liver failure occurs when liver cells are damaged significantly and no longer able to function. Acute liver failure has many potential causes, including:

• Paracetamol overdose. Taking too much paracetamol is the most common cause of acute liver failure. Acute liver failure can occur if you take a very large dose of Paracetamol all at once, or it can occur if you take smaller doses every day for several days, especially in people with chronic liver disease.

• Prescription medications. Some prescription medications can cause acute liver failure, including antibiotics, nonsteroidal anti-inflammatory drugs and anticonvulsants, among others.

• Herbal supplements. Herbal drugs and supplements have been linked to acute liver failure, including kava, ephedra, skullcap and pennyroyal, among others.

• Hepatitis and other viruses. Hepatitis A, hepatitis B and hepatitis E can cause acute liver failure. Other viruses that can cause acute liver failure include Epstein-Barr virus, cytomegalovirus and herpes simplex virus.

• Toxins. Toxins that can cause acute liver failure include the poisonous wild mushroom Amanita phalloides, which is sometimes mistaken for other edible species.

• Autoimmune disease. Liver failure can be caused by autoimmune hepatitis — a disease in which your immune system attacks liver cells, causing inflammation and injury.

• Diseases of the veins in the liver. Vascular diseases that cause blockages to form in the veins of the liver can cause acute liver failure. These include portal vein thrombosis, Budd-Chiari syndrome and venoocclusive disease.

• Metabolic disease. Rare metabolic diseases, such as Wilson's disease, acute fatty liver of pregnancy and Reye's syndrome, infrequently cause acute liver failure.

• Cancer. Cancer that begins in your liver or cancer that spreads to your liver from other places in your body can cause your liver to fail.

Complications

Acute liver failure often causes complications, including:

• Excessive fluid in the brain (cerebral edema). Excessive fluid causes pressure to build in your brain, which can displace brain tissue outside of the space it normally occupies (herniation). Cerebral edema can also deprive your brain of oxygen.

• Bleeding disorders. A failing liver isn't able to produce sufficient amounts of clotting factors, which help blood to clot. Bleeding from ulcers in the gastrointestinal tract or other locations is difficult to control because it doesn't clot quickly.

• Infections. People with acute liver failure are at an increased risk of developing a variety of infections, particularly in the blood and in the respiratory and urinary tracts.

• Kidney failure. Kidney failure often occurs following liver failure, especially in cases of acetaminophen overdose, which damages both your liver and your kidneys. 

How to diagnose Acute Liver Failure

Tests and procedures used to diagnose acute liver failure include:

• Blood tests. Blood tests to determine how well your liver is functioning may include the prothrombin time test, which measures how long it takes for your blood to clot. If you have acute liver failure, your blood doesn't clot as quickly as it should.

• Examination of liver tissue. Your doctor may recommend a procedure to remove a small section of liver tissue (liver biopsy). Tests of the liver tissue may help your doctor understand why your liver is failing. For people with a risk of bleeding during biopsy, such as those with acute liver failure, the doctor performs a transjugular liver biopsy. To do this, a tiny incision is made on the right side of your neck and a thin tube (catheter) is passed into a large vein in your neck, through your heart and down into a vein exiting your liver. Your doctor then inserts a needle down through the catheter and retrieves a sample of liver tissue.

Treatments options

People with acute liver failure are treated in the intensive care unit of a hospital. Acute liver failure treatments may include:

• Medications to reverse poisoning. Acute liver failure caused by Paracetamol overdose or mushroom poisoning is treated with drugs that can reverse the effects of the toxin.

• Relieving excess fluid in the brain. Cerebral edema caused by acute liver failure can increase pressure on your brain. Medications can help reduce the fluid buildup in your brain.

• Screening for infections. Your medical team will take periodic samples of your blood and urine to be tested for signs of infection. If your doctor suspects that you have an infection, you'll receive medications to treat the infection.

• Preventing severe bleeding. People with acute liver failure often develop bleeding ulcers in the gastrointestinal tract. Your doctor will give you medications to reduce the risk of bleeding. If you lose a lot of blood, you may require blood transfusions.

• Liver transplant. Acute liver failure can't be reversed in many cases. In these situations, the only treatment may be a liver transplant. During a liver transplant, a surgeon removes your damaged liver and replaces it with a healthy liver from a donor.

Prevention

Reduce your risk of acute liver failure by taking care of your liver. Try to:

• Follow instructions on medications. If you take Paracetamol or other medications, check the package insert for instructions on the recommended dosage and don't exceed that dosage.

• Tell your doctor about all your medicines. Tell your doctor about over-the-counter and herbal medicines that you're taking. These can interfere with prescription drugs you're taking.

• Drink alcohol in moderation, if at all. Limit the amount of alcohol you drink to no more than one drink a day for women and no more than two drinks a day for men.

• Avoid risky behavior. Get help if you use illicit intravenous drugs. Don't share needles used to inject drugs. If you choose to have sex, use condoms. If you choose to have tattoos or body piercings, be careful about cleanliness and safety when it comes to selecting a shop.

• Get vaccinated. If you're at increased risk of contracting hepatitis, if you've already been infected with any form of the hepatitis virus or if you have chronic liver disease, talk to your doctor about getting the hepatitis B vaccine. A vaccine is also available for hepatitis A.

• Avoid contact with other people's blood and body fluids. Hepatitis viruses can be spread by accidental needle sticks or improper cleanup of blood or body fluids. It's also possible to become infected by sharing razor blades or toothbrushes.

• Take care with aerosol sprays. When you use an aerosol cleaner, make sure the room is ventilated, or wear a mask. Take similar protective measures when spraying insecticides, fungicides, paint and other toxic chemicals. Always follow the manufacturer's instructions.

• Watch what gets on your skin. When using insecticides and other toxic chemicals, cover your skin with gloves, long sleeves, a hat and a mask.

• Choose a healthy diet. Choose a plant-based diet with a variety of fruits and vegetables. Limit high-fat foods.

• Maintain a healthy weight. Obesity can cause a condition called nonalcoholic fatty liver disease, which may include fatty liver, hepatitis and cirrhosis.

References:

http://www.childrenshospital.org/az/Site1241/mainpageS1241P0.html

http://en.wikipedia.org/wiki/Acute_liver_failure

http://www.mayoclinic.com/health/liver-failure/DS00961

http://emedicine.medscape.com/article/177354-overview

http://www.aasld.org/practiceguidelines/Documents/Bookmarked%20Practice%20Guidelines/acute%20liver%20failure.pdf

http://ceaccp.oxfordjournals.org/content/4/2/40.full

http://www.livertox.nih.gov/Phenotypes_fail.html