Liver failure is one of the leading causes of death worldwide. In the eight economically leading countries of the world alone, over 100,000 patients die each year from end-stage or acute liver failure, and liver disease is the 10th most frequent cause of death. The majority of patients die while at hospital due to the deterioration of existing liver cirrhosis caused for example by infection.
Due to its central role in various processes loss of liver function is accompanied by the dysfunction of many other organs further contributing to the severity of the disease. Signs and symptoms also develop due to the buildup of toxins in the body, which are normally metabolized by the liver. Fortunately, the liver has an amazing regeneration capacity. It is known from Living donor liver transplantation that only about 20-30% of a normal liver is sufficient to survive. The liver usually recovers after transplantation to normal size and function within only 3 months.
In general, Liver failure can be differentiated into acute liver failure (ALF) and chronic liver failure (CLF).
Acute liver failure (ALF) is among the most catastrophic afflictions of humans. It is a form of rapid-onset liver failure, also known as fulminant hepatic failure, caused by severe liver injury or massive loss of hepatocytes (the main liver cells). ALF is characterized by sudden development (within 2 weeks) of liver dysfunction, yellowing of the skin, abnormal blood clotting and brain and nervous system dysfunction (the so called encephalopathy). The most common causes are viral hepatitis, drugs (e.g. paracetamol overdose) and intoxication (e.g. mushroom poisoning). Complications involving other organ systems include cerebral edema (excessive amount of fluid in the brain), kidney failure, respiratory failure, infection, bleeding, and cardiovascular collapse that may lead to death within a few days or weeks after of the onset of symptoms.
Chronic liver failure is characterized by a continuous reduction of the liver function over years or even decades. It is characterized by cell death and replacement of liver tissue by fibrous scar tissue leading to progressive loss of liver function and irreversible damage of the liver – the so called liver cirrhosis. The most common causes of liver cirrhosis are alcohol (main cause in Europe), chronic viral infections (hepatitis B & C, the main cause in Asia), and obesity with concomitant non-alcoholic fatty liver disease (fastest growing proportion of the various causes for liver cirrhosis). Cirrhosis has no signs or symptoms in its early stages. Approximately 40% of patients with cirrhosis are asymptomatic and the condition is often only discovered during a routine examination with laboratory or radiographic investigations, if not even at autopsy. But as it progresses, it can cause many complications, including accumulation of fluid in the abdomen (ascites), muscle wasting, bleeding disorders (coagulopathy), confusion or a change in the level of consciousness (hepatic encephalopathy), and a number of other problems.
In such patients, a change in diet, alcohol, a general infection (e.g. pneumonia) or rekindling of the basic disease (e.g. in the case of viral hepatitis) can lead to a life-threatening acute deterioration of the liver function the so called acute-on-chronic liver failure (AoC).