Liver failure (GI) Flashcards
Define liver failure.
Rapid decline in hepatic function characterised by jaundice, coagulopathy (INR>1.5) and hepatic encephalopathy in patients (with no evidence of prior liver disease, if acute)
What leads to organ failure in liver failure?
Mostly massive hepatocyte necrosis –> organ failure
Apoptosis also involved
How can we classify liver failure based on length of time between onset of jaundice and development of hepatic encephalopathy? (3)
- hyperacute (<7 days)
- acute (1-4 weeks)
- subacute (4-12 weeks)
Define chronic liver disease.
Condition characterised by progressive deterioration of hepatic function over 6 months e.g. cirrhosis
What are the stigmata of chronic liver disease? (4)
- spider naevi
- gynaecomastia
- Dupuytren’s contracture
- palmar erythema
What are the signs of decompensation (acute deterioration) in chronic liver disease? (3)
- ascites
- jaundice
- encephalopathy
What are the causes of liver failure? (6)
- paracetamol overdose (most common)
- viral hepatitis A-E (A or B usually)
- alcohol excess
- acute fatty liver of pregnancy
- malignancy (e.g. lymphoma)
- idiopathic
What is liver failure characterised by?
Jaundice, coagulopathy (INR>1.5) and hepatic encephalopathy
What are the clinical features of liver failure? (7)
- jaundice - decreased secretion of conjugated BR, pruritus occurs too
- coagulopathy (INR>1.5) - can cause life-threatening bleeds
- encephalopathy
- abdominal pain
- nausea and vomiting
- fever, lethargy, malaise
- acute fatty liver of pregnancy - jaundice following abdominal pain and pruritus during pregnancy
Why does hepatic encephalopathy occur in liver failure?
Ammonia and other toxic substances are unable to be removed by body = go to brain
What are the signs of hepatic encephalopathy in liver failure? (3)
- altered level of consciousness (and mood and behaviour)
- cerebral oedema
- asterixis - inability to maintain sustained posture with subsequent brief, shock-like, involuntary movements
- grades 1-4 (where 4 = coma)
What are the signs of acute fatty liver of pregnancy?
Jaundice following abdominal pain and pruritus during pregnancy
What might you find on examination in liver failure? (7)
- jaundice
- encephalopathy - altered consciousness, cerebral oedema, asterixis
- pyrexia
- cerebral oedema - abnormal pupillary reflexes, muscular rigidity, decerebrate posturing
- fetor hepaticus (pear drops smell)
- hepatomegaly (acute viral hepatitis, CHF with hepatic congestion, Budd-Chiari and infiltrative malignancies)
- absence of splenomegaly
What are some risk factors for liver failure? (7)
- chronic alcohol abuse (accidental paracetamol OD)
- poor nutritional status
- female sex
- pregnancy (increased hepE, acute fatty liver of pregnancy, haemolysis)
- chronic hepatitis B
- chronic pain and narcotic use
- Wilson’s disease
What is the first-line investigation in liver failure?
Prothrombin time/INR - raised indicates coagulopathy (defining feature of ALF), best indicator of liver function
What would LFTs show in liver failure?
- high BR, AST, ALT, ALP, GGT
- low albumin (–> leukonychia)
What else would bloods show in liver failure?
Hypoglycaemia
What different tests can we do to identify the cause of liver failure? (2)
- viral serology
- paracetamol levels
How can we monitor encephalopathy in liver failure?
EEG
How can we look for spontaneous bacterial peritonitis in liver failure?
Peritoneal tap
What are some differential diagnoses for liver failure? (3)
- severe acute hepatitis - jaundice and coagulopathy WITHOUT encephalopathy
- cholestasis - absence of coagulopathy and encephalopathy
- haemolysis - jaundice characterised by raised unconjugated BR
How do we treat liver failure caused by paracetamol OD?
N-acetylcysteine
How do we treat hepatic encephalopathy in liver failure? (3)
- lactulose
- phosphate enemas
- IV mannitol to reduce cerebral oedema (leads to raised ICP)
How do we treat coagulopathy in liver failure?
Vitamin K and FFP
What is the definitive treatment for liver failure?
Liver transplant - all patients should be considered for possible transplant
How do we treat liver failure caused by different causes? (7)
- paracetamol - N-acetylcysteine
- HSV - acyclovir
- HELLP, fatty liver of pregnancy - delivery of foetus
- autoimmune hepatitis - methylprednisolone
- hepatitis B - oral nucleoside or nucleotide analogue
- Budd-Chiari - anticoagulation, TIPS
- Wilson’s disease - plasmapheresis, continuous veno-venous haemofiltration, albumin dialysis or plasma exchange
How do we treat liver failure caused by autoimmune hepatitis?
Methylprednisolone
How do we treat liver failure caused by hepatitis B?
Oral nucleoside or nucleotide analogue
What can we give for gastric mucosa protection in liver failure?
PPIs or sucralfate (prevent duodenal ulcers)
What drugs do we avoid in liver failure?
Avoid sedatives or drugs metabolised by liver
What are some complications of liver failure? (5)
- infection
- coagulopathy (–> GI bleeding)
- cerebral oedema (leads to raised ICP)
- respiratory failure
- hepatorenal syndrome
Why does cerebral oedema occur in liver failure?
As liver fails, nitrogenous waste builds up and passes to the brain where astrocytes clear it, by processes involving conversion of glutamate –> glutamine
Excess glutamine causes osmotic imbalance and fluid shift into cells –> cerebral oedema
