• The most severe clinical consenquences ofliver disease is hepatic failure . It generallydevelops as the end point of progressivedamage to the liver,• either insidious destruction of hepatocytes or• repititive discrete waves of parenchymaldamage.
• Less commonly, hepatic failure is the resultof sudden and massive destruction of hepatictissue.• Whatever the sequence, 80% to 90% ofhepatic function must be lost before hepaticfailure ensues.
DefinitionLiver failure is the inability of the liver toperform its normal synthetic and metabolicfunction as part of normal physiology.Two forms are recognized, acute and chronic.
• A course expending as long as 3 months iscalled subacute failure.
• The alterations that cause liver failure fall intothree categories:• 1. Acute liver failure with massive hepaticnecrosis• 2. Chronic liver disease• 3. Hepatic dysfunction without covertnecrosis
Acute Hepatic Failure• Acute hepatic failure is defined as "the rapiddevelopment of hepatocellular dysfunction,specifically coagulopathy and mental statuschanges (encephalopathy) in a patientwithout known prior liver disease".
Acute liver failure with massive hepatic necrosis• Caused by drugs or fulminant viral hepatitis• ALF denotes clinical hepatic insufficiency thatprogresses from onset of symptoms to hepaticencephalopathy within 2 to 3 weeks.
Morphology• The histologic correlate of acute liver failure ismassive hepatic necrosis.
ChroniC hepatiC failure• Chronic hepatic failure usually occurs in thecontext of cirrhosis.
Chronic liver disease• This is the most common route to hepaticfailure and is the end point of relentless chronicliver damage ending in cirrhosis.
Causes of CLF• The most common causes of chronic liver failure(where the liver fails over months to years) include:• Hepatitis B• Hepatitis C• Long term alcohol consumption• Cirrhosis• Hemochromatosis (an inherited disorder that causesthe body to absorb and store too much iron)• Malnutrition
Hepatic dysfunction without overtnecrosis• Hepatocytes may be viable but unable toperform normal metabolic function,
Types ABC• Type A (=acute) describes hepatic encephalopathyassociated with acute liver failure, typicallyassociated with cerebral oedema• Type B (=bypass) is caused by portal-systemicshunting without associated intrinsic liver disease• Type C (=cirrhosis) occurs in patients with cirrhosis -this type is subdivided in episodic, persistent andminimal encephalopathy
Early symptoms• Nausea• Loss of appetite• Fatigue• Diarrhea
Serious Symptoms• Jaundice• Bleeding easily• Swollen abdomen• Mental disorientation or confusion (known ashepatic encephalopathy)• Sleepiness• Coma
Complications of Hepatic Failure• Coagulopathy• Hepatic encephalopathy• Hepatorenal syndrome
Hepatic encephalopathy• Hepatic encephalopathy (also known asportosystemic encephalopathy) is theoccurrence of confusion,altered level of consciousness, and coma as aresult of liver failure. In the advanced stages itis called hepatic coma or coma hepaticum. Itmay ultimately lead to death.
West Haven Criteria• Grade 1 - Trivial lack of awareness; euphoria oranxiety; shortened attention span; impairedperformance of addition or subtraction• Grade 2 - Lethargy or apathy; minimaldisorientation for time or place; subtlepersonality change; inappropriate behaviour• Grade 3 - Somnolence to semistupor, butresponsive to verbal stimuli; confusion; grossdisorientation• Grade 4 - Coma (unresponsive to verbal ornoxious stimuli)