Acute-on-Chronic Liver Failure
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Direct answer
Acute-on-chronic liver failure is an acute decompensation of pre-existing chronic liver disease, usually cirrhosis, with failure of one or more organs. It is graded by the number of failing organs, and it differs from acute liver failure, which occurs without known prior liver disease. Common precipitants include bacterial infection, alcoholic hepatitis, gastrointestinal bleeding and hepatitis flares, and short-term mortality is high, rising with each additional failing organ.
What you must remember
- APASL definition: prior chronic liver disease with bilirubin of 5 mg/dL or more and INR of 1.5 or more, complicated within four weeks by ascites or encephalopathy.
- Organ failure scoring: CLIF-SOFA assesses liver, kidney, brain, coagulation, circulation and respiration.
- Grades: EASL-CLIF grades 1 to 3 by the number of failing organs, with grade 3 carrying the highest mortality.
- Commonest precipitant: bacterial infection in Western series, classically spontaneous bacterial peritonitis; in Asia-Pacific and Indian series, hepatitis B reactivation and alcoholic hepatitis are also leading triggers.
- Other precipitants: alcoholic hepatitis, gastrointestinal bleeding, hepatitis B reactivation or other flares, and drug injury.
- Acute liver failure contrast: no prior liver disease, with encephalopathy within 26 weeks of jaundice.
- Transplant timing: early referral for grade 3 failure or poor recovery, since delay can make the patient ineligible.
Grading by number of failing organs
A 48-year-old man with alcoholic cirrhosis is admitted with jaundice, grade 3 encephalopathy and a creatinine of 2.5 mg/dL after a week of fever. Two organs are failing, so the examiner asks for the grade and what it implies. Each organ is scored on a standard scale, so the count is objective and repeatable.
| Grade | Organ failure | Relative short-term mortality |
|---|---|---|
| Grade 1 | Single kidney failure, or one other organ failure with mild kidney or brain dysfunction | Lower |
| Grade 2 | Two organs | Intermediate |
| Grade 3 | Three or more organs | Highest |
Grade reflects the number of failing organs rather than the cause of decompensation. The scoring guides prognosis and the urgency of referral, and a rising grade on repeat assessment signals a worsening course. Grade is therefore recalculated at follow-up, because improvement or deterioration over days changes the expected outcome.
Transplant assessment is requested early, because grade 3 failure and poor recovery after treating the precipitant are the groups most likely to need a liver transplant. Waiting too long can make a patient ineligible, so referral timing is part of management rather than a last resort.
Where the exam tests the ACLF trap
Acute-on-chronic liver failure is confused with simpler forms of decompensation, so the examiner tests the definition carefully.
- Trap: labelling every decompensated cirrhosis as ACLF Correct: ACLF needs organ failure by EASL-CLIF criteria (or the APASL bilirubin and INR thresholds), not ascites or encephalopathy alone.
- Trap: treating ACLF as acute liver failure because the jaundice is acute Correct: acute liver failure lacks prior cirrhosis, whereas ACLF is graded by organ count and depends on the precipitant.
- Trap: overlooking infection as the trigger Correct: bacterial infection is a leading precipitant, so cultures and early antibiotics are essential.
Frequently asked questions
What defines acute-on-chronic liver failure under APASL criteria?
Under APASL criteria, acute-on-chronic liver failure is prior chronic liver disease with bilirubin of 5 mg/dL or more and an INR of 1.5 or more. These features must be complicated within four weeks by ascites or encephalopathy.
How does acute-on-chronic liver failure differ from acute liver failure?
Acute liver failure occurs in people without known prior liver disease and causes encephalopathy within 26 weeks of jaundice. Acute-on-chronic liver failure occurs on top of cirrhosis, is graded by the number of failing organs, and its outcome depends on that count.
Which precipitant is most common in acute-on-chronic liver failure?
Bacterial infection is the most common precipitant of acute-on-chronic liver failure in Western series, and spontaneous bacterial peritonitis is a classic example. Hepatitis B reactivation and alcoholic hepatitis are leading triggers in Asia, and cultures and early antibiotics remain essential.
When should a patient with acute-on-chronic liver failure be referred for transplant?
Patients with grade 3 failure, or those who do not recover after the precipitant is treated, should be referred for transplant assessment early. Waiting too long can make a patient ineligible, so referral timing is part of management rather than a last resort.