acute liver failure W5 Flashcards
what does failure to clear bilirubin lead to
jaundice
what does failure to clear gut-derived toxins lead to
encephalopathy
what does failure to produce clotting factors lead to
coagulopathy on blood tests
what does failure to produce albumin lead to
oedema, impaired binding of drugs
what does failure to store or release glucose lead to
hypoglycaemia
what does failure to utilise carbohydrate lead to
muscle breakdown
time scales of acute vs chronic liver failure?
acute <2-3 months
chronic >2-3 months
what is albumin? functions?
key circulating protein, binds to many things, helps with fluid balance
acute liver failure defining features?
rapid onset, no underlying chronic liver disease
features of acute liver injury?
acute liver injury = high ALT
common
features of severe acute liver injury?
severe acute liver injury = high ALT + jaundice/coagulopathy
uncommon
what is ALT?
alanine transaminase. enzyme found in liver. when hepatocytes are damaged, ALT is released into the bloodstream
features of acute liver failure?
acute liver failure = high ALT + jaundice/coagulopathy + encephalopathy
rare
common causes of ALF?
paracetamol (80-90% of cases)
other drugs (antibiotics, antiepileptics, herbal remedies, ecstasy)
acute viral infections (hep B/A/E)
autoimmune hepatitis
seronegative hepatitis
rare causes of ALF?
vascular diseases (Budd-Chiari)
metabolic diseases (Wilson’s, acute fatty liver of pregnancy)
cancer
ischaemia (hypotension)
toxins (amanita phalloides mushroom, carbon tetrachloride)
what can help reduce oxidative stress caused by paracetamol overdose
N-acetyl cysteine infusion
what is vitamin K treatment used to correct in ALF?
correction of coagulopathy
how does vitamin K correct coagulopathy in ALF?
vitamin K is a substrate required for certain clotting factor synthesis.
if dietary deficiency, clotting will look worse than liver function really is so give vitamin K.
replacement will not mask liver dysfunction.
what is FFP?
what is it used for?
should it be given for ALF? why/why not?
fresh frozen plasma
blood product containing clotting factors
correct clotting in the situation of bleeding
replacement will prevent use of clotting times as a marker of liver function so try to avoid giving for ALF
what is IV dextrose given for? (ALF)
given for low blood sugar to prevent confusion, drowsiness, coma
anuria as a symptom of ALF?
not producing any urine
due to renal dysfunction
why may low BP be a symptom of ALF? how is this treated?
response to systemic inflammation because of dead liver producing inflammatory response
treated with vasopressors, noradrenaline
what causes agitation and confusion in ALF?
encephalopathy
what criteria is used to decide prognosis in paracetamol ALF?
unlikely to recover spontaneously if
PT >100 and
anuric/creatinine >300 and
grade 3-4 encephalopathy (stupor/coma)
stupor meaning?
state of near unconsciousness
contraindications for transplant for paracetamol ALF?
alcohol?
previous overdoses?
depressed?
what is falling ALT in acute liver injury a sign of?
either hepatocyte injury improving or because there’s not enough healthy liver left to produce it
what is seronegative hepatitis?
non A-E hepatitis
unexplained agent causing significant damage, no treatment option.
possible outcomes of seronegative hepatitis?
liver regenerates and recovers fully
liver fails to regenerate and needs transplant
factors to determine prognosis in non-paracetamol ALF?
3/5 of following = unlikely to recover spontaneously
age <10 or >40
aetiology = drug/seronegative
PT>50 or INR>3.5
bilirubin>300
time from jaundice to encephalopathy <7d
ALF management - treating underlying cause?
NAC for paracetamol
antivirals for hep B
steroids for autoimmune hepatitis
