Hepatic Failure: Types, Causes, Symptoms, Treatment, Pathophysiology
What is Hepatic Failure?
The liver is one of the most important and the second largest organ in the body. It is responsible for performing different functions in our body. Whatever we eat or drink is processed by our liver, as the liver converts the food and drinks, which we consume, into nutrients and energy which is used by our body. Liver also helps in filtering out the harmful substances, such as alcohol, from our blood. Liver is also responsible for fighting off infections in our body.
When there is damage to the liver, a person can suffer from liver failure or hepatic failure. Harmful chemicals and viruses can also harm the liver. In individuals who have liver damage, their liver can gradually stop functioning, which can be very deadly for the patient.
Hepatic failure or liver failure is an extremely fatal condition and treatment should be sought immediately for it. If hepatic failure is detected in its early stage, then it can be treated and patient can lead a normal life.
Pathophysiology of Hepatic Failure
Hepatic failure develops as a result of various pathways, but majority of the times, it is characterized by massive necrosis of the hepatocytes, which ultimately results in hepatic failure. However, there are cases where hepatic failure can occur without the histological evidence of hepatocellular necrosis, such as seen in acute fatty liver of Reye's syndrome and pregnancy. According to research, both the apoptosis and hepatocyte necrosis can coexist in the setting of hepatic failure. If we try to accurately define the factors which are involved in the pathogenesis of hepatic injury in the setting of hepatic failure which includes hepatocyte apoptosis and regeneration, it can result in identification of unique biomarkers which can help in predicting the outcomes. Hepatic failure occurring due to drug-induced liver injury tends to occur as an idiosyncratic drug reaction. In case of paracetamol (acetaminophen), it can occur in a dose-dependent manner. Paracetamol is primarily metabolized in the liver through sulphation and glucuronidation and a small amount of it is metabolized by the cytochrome P450 system. N- acetyl-p-benzoquinoneimine (NAPQI) is a toxic intermediate which is produced through the P450 pathway and is later conjugated by glutathione. When there is a paracetamol overdose, there is depletion of these glutathione stores which results in direct hepatocyte injury through NAPQI. Chronic use of alcohol or barbiturates and depletion of glutathione stores can lead to induction of the P450 system, especially in the setting of nutritional deficiency which can result in an increased predisposition to develop paracetamol hepatotoxicity.
Types of Hepatic Failure
Acute Hepatic Failure
Acute hepatic failure occurs very fast. Deterioration of liver function can occur within a few weeks or even days. Acute hepatic failure can occur abruptly without any symptoms or warnings. Some of the common causes of acute hepatic failure are drug overdose (taking overdose of acetaminophen) or poisoning from mushrooms.
Chronic Hepatic Failure
Chronic hepatic failure occurs slower than acute hepatic failure. Chronic hepatic failure can occur over months and even years before the patient starts to have any symptoms. The common cause of chronic hepatic failure is cirrhosis, which occurs as a result of long-term alcohol use. Cirrhosis is a condition which is characterized by replacement of healthy liver tissue with scar tissue.
What is Cirrhosis?
When chronic hepatic failure occurs, there is inflammation of the liver resulting in formation of scar tissue. As our body continues to replace the healthy liver tissue with scar tissue, the liver starts to fail.
Types of Alcohol-Related Hepatic Failure
- Alcoholic fatty liver disease occurs when there is deposition of fat cells in the liver. This condition occurs in those people who consume a lot of alcohol and are obese.
- Alcoholic hepatitis occurs when there are fat cells present in the liver along with scarring and inflammation. According to studies, about 35% of heavy alcohol drinkers can develop this condition.
- Alcoholic cirrhosis is thought to be most advanced type of Alcohol-Related Hepatic Failure. According to studies, this condition affects around 10 -20 % of heavy alcohol drinkers.
Causes of Hepatic Failure
A patient can have an acute hepatic failure (also known as fulminant hepatic failure) even when he/she does not have any preexisting liver disease. One of the most common causes of acute hepatic failure is drug overdose and specifically acetaminophen (Tylenol) overdose. Patients should always read the instructions carefully and take only the recommended dosage written on the label. If there is a suspicion of an overdose, then the patient should visit their doctor immediately. There are cases where patient can develop acute hepatic failure and the exact cause is not known.
Other known causes of acute hepatic failure are:
- Some herbal supplements.
- Certain prescription medicines.
- Viral infections, such as hepatitis (A, B, and C).
- Certain autoimmune diseases.
- Acute hepatic failure can also be genetic. If the patient has a genetic liver disease, then he/she is at an increased risk for hepatic failure.
- The common cause for chronic hepatic failure is cirrhosis or alcohol-related liver disease. According to studies, alcohol is the commonest cause of cirrhosis in America.
- Normally, the human liver breaks down any alcohol which a person consumes; however, if alcohol is consumed in excessive amounts then the liver is unable to keep up.
- Alcohol contains toxic chemicals which trigger inflammation in the liver, causing swelling in the liver. All this damage causes gradual development of cirrhosis.
Risk Factors for Hepatic Failure
- Individuals suffering from hepatitis C are at an increased risk for developing cirrhosis or chronic hepatic failure. The virus of the hepatitis C spreads through blood. If the infected blood enters a healthy human body, then that person can contract hepatitis C. Sharing needles, using unhygienic and dirty needles during piercings or tattooing are some ways through which hepatitis C spreads.
- People who are obese or overweight are at an increased risk for developing fatty liver disease.
- Consumption of diet which is high in fat also increases the risk for developing fatty liver disease.
- Changing your lifestyle and consuming a healthier diet helps. Consumption of alcohol should also be stopped or reduced, especially if you have liver damage.
Symptoms of Hepatic Failure
- Patient suffering from Hepatic Failure experiences symptoms of loss of appetite.
- Patient has nausea.
- Patient has diarrhea.
- Hepatic Failure patients also feel symptoms of being tired and fatigued.
- Jaundice occurs.
- There is weight loss.
- Patient has itching.
- There is easy bruising or bleeding in Hepatic Failure patients.
- Edema or accumulation of fluid in the legs.
- Ascites or buildup of fluid in the abdomen.
These symptoms can also occur in other medical disorders. This makes the diagnosis of hepatic failure difficult. There are some patients who do not exhibit any signs of liver failure till it has progressed to a fatal stage. Patient is disoriented, drowsy and can also become comatose when he/she has reached the fatal stage of hepatic failure.
If the patient has alcohol-related hepatic disease, then he/she can develop jaundice, or a yellowish color of the eyes and skin. There is buildup of toxins in the brain causing sleeplessness, decreased mental function and lack of concentration in the patient. There may also be spleen enlargement, bleeding in the stomach, and kidney failure. Patient can also develop liver cancer.
Investigations to Diagnose Hepatic Failure
If you are experiencing the above mentioned symptoms, then seek medical advice immediately. If you have a history of genetic abnormalities, alcohol abuse or are suffering from medical conditions then be sure to convey all this to your doctor. There are various blood screening tests that can detect abnormalities in the blood which can indicate liver failure among other conditions.
If you are suffering from drug poisoning or medication overdose, such as from acetaminophen, then the doctor can prescribe medication, which will reverse the effects. Medications are also prescribed to stop any internal bleeding. Imaging tests of the liver are done to assess the extent of the damage to the liver.
A biopsy is a test which helps in determining the extent of the damage to the liver. In a liver biopsy, a small piece of the liver is excised and sent to lab for testing. If the damage to the liver is caught early, then some of the liver damage can be reversed. Medications can help with the repair process or the damaged liver may repair itself.
Treatment for Hepatic Failure
The treatment of hepatic failure depends on the stage of the disease. Medications may be prescribed. If there is damage to only a small part of the liver, then surgery is done to remove the damaged part. If the damage to the liver is very severe, which can be in patients who have fast-acting acute hepatic failure, then a liver transplant may be the only way.
Patient should never neglect the symptoms of hepatic failure and should consult doctor at the earliest. Your symptoms may or may not be due to hepatic failure, but if it is from hepatic failure, then early detection of this condition is important, as hepatic failure can be a silent killer because sometimes the patient does not experience any symptoms until it is too late. If diagnosis is made and treatment is started on time then the liver disease can be controlled and the patient can lead a normal life.
Prevention of Hepatic Failure
- Reducing or completely stopping the alcohol consumption is one of the easiest ways to prevent hepatic failure.
- Following a healthy and low fat diet.
- Practicing safe sex.
- Not sharing needles or engaging in drug use.
- Being up-to-date on vaccinations for hepatitis.
- Skin should be protected from toxic chemicals.
- Aerosol spray cans should always be used in ventilated areas.