AKT · Gastroenterology/Liverlow yield

Acute liver failure

Rapid loss of hepatic function without pre-existing chronic liver disease (paracetamol, viral, drugs)

Overview

Rapid loss of liver function (coagulopathy + hepatic ENCEPHALOPATHY) developing within weeks in a patient WITHOUT pre-existing chronic liver disease. In the UK the commonest cause is PARACETAMOL overdose; also viral (B, E in pregnancy, A), drug reactions, Wilson's, Budd-Chiari, autoimmune. A medical emergency — supportive critical care, treat the cause (N-acetylcysteine for paracetamol), and consider transplant (King's College criteria).

Recognise

Jaundice, coagulopathy (raised INR not corrected by vitamin K), and hepatic ENCEPHALOPATHY within weeks, no chronic liver disease
Complications: cerebral oedema/raised ICP, hypoglycaemia, AKI/hepatorenal, sepsis, multi-organ failure
Paracetamol: staggered/large overdose; check timing and levels

Red flags

Encephalopathy/cerebral oedema, hypoglycaemia, rising INR/lactate → transplant centre (King's College criteria)
Paracetamol toxicity → N-acetylcysteine without delay

Differentials & how to tell them apart

Decompensated chronic liver diseasepre-existing cirrhosis/stigmata — acute liver failure is in a previously normal liver

Sepsis/other encephalopathymetabolic/septic encephalopathy without the synthetic liver failure

Wilson diseaseyoung, haemolysis, low ALP:bilirubin ratio (see endocrine/metabolic)

Investigations

INR/coagulation (key marker), LFTs, glucose (hypoglycaemia), U&Es (hepatorenal), ABG/lactate, ammonia; paracetamol level + toxicology; viral serology, autoantibodies, caeruloplasmin; USS/Doppler (Budd-Chiari).

Management

Critical care + treat the cause (N-acetylcysteine) + transplant assessment (King's criteria)

1Treat the cause (N-acetylcysteine for paracetamol) and provide supportive critical care (glucose, coagulopathy, cerebral oedema, renal/sepsis support). Early discussion with a transplant centre.Gate: Assess transplant eligibility with the King's College criteria early (e.g. paracetamol: arterial pH 6.5 + creatinine >300 + grade III/IV encephalopathy) — don't delay referral; avoid sedatives that mask encephalopathy
2Transplant for those meeting criteria; manage complications in ICU; treat the specific cause.

N-acetylcysteine (paracetamol — and benefit in non-paracetamol ALF) — the antidote; give early

Supportive critical care — glucose, manage cerebral oedema (mannitol/hypertonic saline), coagulopathy, renal support, sepsis

Liver transplantation — per King's College criteria (e.g. paracetamol: pH <7.3, or the INR/creatinine/encephalopathy triad)

Key points

Coagulopathy + encephalopathy in a previously normal liver = acute liver failure (UK: paracetamol commonest) → NAC + critical care + early transplant assessment (King's criteria). INR is the key marker; it's different from decompensated cirrhosis (pre-existing chronic disease).

Monitor & prognosis

INR, glucose, lactate, neurology (cerebral oedema).

Variable; transplant for those meeting criteria.

Source: King's College criteria; EASL