Acute liver failure

Question 1

liver failure

Answer 1

liver dysfunction
coagulopathy - PT >4-6s
hepatic encephalopathy
in the absence of known liver disease

commonest cause in the UK is paracetamol od

http://www.nejm.org/doi/full/10.1056/nejmra1208937

Question 2

paracetamol poisoning

Answer 2

toxic metabolites cause the liver injury, once glutathione (detoxifies the metabolites) becomes saturated

high risk: malnourished, enzyme inducers, alcohol, rifampicin

worst outcomes in those who have taken staggered overdoses

Question 3

n-acetylcysteine

Answer 3

if administered within 8-10hrs of paracetamol od it is hepato-protective. significant reduction in mortality, hepatic encephalopathy., this is also the case in patients after 10hrs
if in doubt - treat

Question 4

blood tests

Answer 4

for paracetamol od:
ABG
lactate
ammonia

Question 5

massive transaminitis

Answer 5

ALT will rise until reaches a peak, but can then reduce. this is not a sign that the disease is improving, rather the level of hepatocyte death, meaning that less can be produced. consider bilirubin levels as well, as these will continue to rise

can be due to viral causes or drugs and toxins. also consider AIH, wilson’s (will often also have a haemolytic anaemia), acute fibroma of pregnancy

Question 6

hep E

Answer 6

most common cause of acute viral hepatitis in the UK

can result in fulminant (acute) liver failure

Question 7

ammonia-glutamine-brain swelling hypothesis

Answer 7

leads to cerebral oedema
glutamine is a metabolite of ammonia, which accumulates in glial cells and shifts the osmotic balance, pulling water into astrocytes
leads to raised ICP

Question 8

transplant criteria

Answer 8

seronegative hepatitis is a high risk if PT>100 or INR>6.5, and will be listed for transplant without the need for the patient to become encephalopathic