Acute liver failure Flashcards
What is liver failure?
The most severe consequence of liver disease is liver disease.
It may be the result of sudden and massive hepatic destruction (acute liver failure).
It might be an insidious, progressive liver injury (chronic liver failure).
In some cases, individuals with chronic liver disease develop acute on chronic liver failure.
What is acute liver failure?
This occurs within 26 weeks of the initial liver injury in the absence of pre-existing liver disease.
Within this 26 week window, it is useful to know the interval between the onset of symptoms and liver failure-it may provide helpful clues to the aetiology.
Causes of acute liver failure
Drugs- 50% of cases are caused by accidental or deliberate ingestion of acetaminophen.
Other drugs/toxins.
Acute hepatitis A and B infections.
Failure due to hepatitis viruses take longer to develop than acetaminophen.
Signs & symptoms of acute liver failure
It first manifests with nausea, vomiting and jaundice.
Followed by life-threatening encephalopathy and coagulopathy.
If the liver is initially enlarged due to hepatocyte swelling, inflammatory infiltrates and oedema; as parenchyma is destroyed, the liver shrinks dramatically.
There’s usually a worsening of jaundice, coagulopathy and encephalopathy with unabated progression.
Prognosis of acute liver failure
If untreated, multiple system failure occurs and if transplantation is not possible, death ensues.
Portal hypertension, ascites and hepatorenal syndrome also occurs.
What is hepatic encephalopathy?
A spectrum of disturbances in consciousness, ranging from subtle behavioural abnormalities to marked confusion and stupor, to deep coma and death.
Encephalopathy may progress over days, weeks or months following acute injury.
Elevated ammonia levels in blood and CNS correlate with impaired neuronal function and cerebral oedema.
This is a defining feature of ALF.
What is the West Haven Criteria?
It is used to grade hepatic encephalopathy.
Grade 1: Sleep reversal, mild lack of awareness, shortened attention span and impaired computations.
Grade 2: Lethargy, poor memory, personality change and the development of asterixis on physical exam.
Grade 3: Progresses to somnolence, confusion, disorientation, and physical findings that include hyper-reflexia, nystagmus, clonus and rigidity.
Grade 4: Stupor and coma.
Risk factors of acute liver failure
Female sex Age > 40 years Pregnancy Chronic pain Poor nutritional status Chronic alcohol abuse Chronic hepatitis B (flare up)
Investigations
LFTs PT FBC ABG Blood type Chest x-ray Pregnancy test Viral hepatitis serologies Factor V level Urine toxicology screen
Differentials of acute liver failure
Haemolysis
Severe acute hepatitis
Cholestatsis
Management approach of acute liver failure
Liver transplantation
Patients should be admitted to the ICU
