Acute liver failure Flashcards
What is acute liver failure?
- Rapid progressive deterioration in liver function
- Encephalopathy is a cardinal feature
- Onset is 8-21 days
Describe hyperacute liver failure?
Onset =<7 days
Describe fulminant liver failure?
Severe impairment of liver function in the absence of pre-existing liver disease
Describe subacute liver failure?
- Onset 4-12 weeks
- Cerebral oedema is uncommon
Describe Chronic liver failure?
Liver failure on a background of cirrhosis
Common causes of Acute liver failure?
- Drugs
- Viral infections
- Poisons
- Miscellaneous
Describe the clinical signs of liver disease?
- Hepatic encephalopathy +/- cerebral oedema
- Weakness, N/V
- Jaundice
- Drowsiness -> coma
- Fetor hepaticus (breath of death, thiols in the lung)
Describe some diagnostic tests for liver failure?
- Toxicology screen on blood and urine
- Hepatitis virus testing (Hepatitis B core IgM antibody, HBsAg)
- Caeruloplasmin, serum copper, urinary copper
- Autoantibodies: ANA. ASMA, LKM, SLA
- Bilirubin reflects degree of jaundice
- Aminotransferases will be very high immediately after paracetmol OD
- US of liver and doppler of hepatic veins
How you treat seizures associated with liver failure?
Phenytoin
Describe the treatments for some common complications of liver failure?
- Cerebral oedema:
- IV mannitol, hyperventilate
- Ascites:
- restrict fluid, low salt diet, diuretics
- Blind infection treatment:
- ceftriaxone
What indicates a worse prognosis in liver failure?
- Grade III-IV encephalopathy
- Age >40
- Albumin <30g/L
- Raised INR
- Drug-induced liver failure
Describe prescribing in liver failure?
- Avoid:
- Drugs that constipate, oral hypoglycaemics, saline containing IVs
- Warfarin effects are enhanced
- Hepatotoxic drugs to remember:
- Paracetamol, methotrexate, isoniazid, azathioprine, phenothiazines, oestrogen, 6-mercaptopurine, salicylates, tetracycline, mitomycin
Describe Hepatic encephalopathy?
- Liver failures => nitrogenous waste (ammonia) builds up in circulation and brain
- Astrocytes clear the ammonia
- Through processes which convert glutamate to glutamine
- Excess glutamine causes fluid shift hence cerebral oedema
Describe the different stages of Hepatic encephalopathy?
- I: Altered mood, sleep disturbance
- II: Confusion, slurred speech
- III: Incoherent; liver flap
- IV: Coma
Describe Hepatorenal syndrome (HRS)?
- Cirrhosis + ascites + renal failure
- Splanchnic and systemic vasodilation, but renal vasoconstriction
- May require liver transplant
Types of HRS?
- HRS-1
- Rapidly, progressive deterioration
- Median survival <2 weeks
- Terlipressin resists hypovolaemia. Haemodialysis by be required.
- Rapidly, progressive deterioration
- HRS-2
- Steady deterioration
- Median survival 6 months
- TIPSS
- Steady deterioration
Name a set of criteria that can predict poor outcomes and need for liver transplantation in Acute liver failure?
King’s college hospital criteria
Most common cause of acute liver failure worldwide?
Acute viral hepatitis
Most common cause of acute liver failure in the UK?
Paracetamol toxicity
Drugs which can cause acute liver failure?
- Paracetamol
- Halothane
- Anti-TB drugs
- MDMA
- Herbal remedies
Viral causes of acute liver failure?
- Hepatitis A, B, E (rare)
Miscellaneous causes of Acute liver failure?
- Wilson’s disease
- Acute fatty liver from pregnancy
- Shock and cardiac failure
- Budd-Chiari syndrome
- Leptospirosis
- Liver metastases
- Lymphoma
SWAB LLL
Describe the clinical grading of hepatic encephalopathy?
- Grade I
- Poor concentration, slurred speech
- Grade II
- Drowsy but rousable, aggressive behavioue
- Grade III
- Delirium, sleepy, disorientation
- Grade IV
- Unconscious
What is the adverse prognostic criteria for Acute liver failure from paracetamol overdose?
- H+ > 50
- Serum creatinine > 300
- PT > 100 secs
- Encephalopathy grade 3 or 4
What is the adverse prognostic criteria for Acute liver failure from non-paracetamol causes?
- PT > 100 seconds
- Factor V level < 15% + encephalopathy 3 or 4
- Any 3 of the following:
- Jaundice to encephalopathy time >7 days
- Age <10 or >40
- Indeterminate or drug induced causes
- Bilirubin > 300
- PT > 50 seconds
Complications of Acute liver failure?
- Cerebral oedema
- Hyoglycaemia
- Metabolic acidosis
- Infection (bacterial or fungal)
Describe Wilson’s disease?
- Autosomal recessive
- Excessive copper deposition in tissues
- Elevated 24h urinary copper excretion
- Low caeruloplasmin and serum copper
Physiology of copper?
- Absorbed in stomach and proximal small intestine
- Rapidly taken into the liver
- Stored and incorporated into caeruloplasmin
- Normal excretion from body in bile
Pathophysiology of Wilson’s disease?
- Failure of synthesis of caeruloplasmin
- Involves mutation of ATP7B gene on chromosome 13
Features of Wilson’s disease?
- Episodes of acute hepatitis -> cirrhosis
- Extrapyramidal features
- Tremor, parkinsonism, dementia
- Kayser-Fleischer rings
- Haemolytic anaemia
- Renal tubular acidosis
Investigations into Wilson’s disease?
- Low serum caeruloplasmin
- High serum copper
- High urine copper
- Measure 24h urinary copper excretion
Describe the management of Wilson’s disease?
- Pencillamine
- Copper binding agent
- Can be continued throughout pregnancy
- May require liver transplant
Describe Budd-Chiari syndrome?
- Thrombosis of large hepatic veins
- Associated with haematological disorders
- eg myelofibrosis, protein C/S deficiencies
- Hepatic congestion affecting centrilobular areas -> centrilobular fibrosis
Clinical features of Budd-chiari?
- Rapid development of:
- Upper abdominal pain
- Ascites
- Tender hepatomegaly
- Peripheral oedema if IVC involved
- Cirrhosis and portal HTN in those who survive acute event
Investigations into Budd-chiari?
- LFTs
- Ascitic fluid analysis: high protein in early stages
- Doppler US
- Obliteration of hepatic veins
- CT
- Enlargement of caudate lobe
- Liver biopsy
- Centrilobular congestion with fibrosis
Management of Budd-chiari syndrome?
- Thrombolysis w/ streptokinase
- Followed by heparin and oral anticoagulation
- Liver transplant
Describe Leptospirosis?
- Zoonotic disease
- Leptospires (motile, thread-like organisms)
- Enter human house through skin or mucous membranes
