Acute liver failure (ALF) is defined as the rapid development of coagulopathy (INR ≥1.5) and hepatic encephalopathy in a patient with no prior evidence of chronic liver disease, with a disease course of ≤26 weeks. [1-2] It is a rare (1–6 cases per million/year) but life-threatening emergency that demands immediate recognition, etiology-directed treatment, and early contact with a liver transplant center. [1][3]
The following clinical algorithm outlines the initial evaluation and management approach:
1. History
- Timeline: Onset and progression of jaundice, malaise, nausea/vomiting, abdominal pain — distinguish hyperacute (0–7 days, e.g., acetaminophen, ischemia) from acute (7–21 days) and subacute (>21 days to 26 weeks) presentations [3][5]
- Medication review: Exhaustive inventory of prescription drugs, OTC medications (especially acetaminophen — including combination products), herbal/dietary supplements (CAM), and controlled substance monitoring databases [3]
- Ingestion history: Intentional vs. unintentional overdose, time of ingestion, amount, co-ingestants, sustained-release formulations; history of suicidal ideation [3][6]
- Viral risk factors: Travel history, sexual contacts, IV drug use, blood transfusions, tattoos [3]
- Toxin exposures: Mushroom ingestion (Amanita phalloides), industrial chemicals, recreational drugs [3]
- Pregnancy status: Acute fatty liver of pregnancy (AFLP), HELLP syndrome [2]
- Alcohol use: Quantity, duration — chronic alcohol consumption worsens ALF outcomes [3]
- Important negatives: Prior liver disease, known cirrhosis, prior episodes of jaundice or decompensation [3]
2. Alarm Features
- Rapidly worsening encephalopathy (especially progression to grade 3–4): indicates impending cerebral edema and need for intubation [1][3]
- Arterial ammonia >200 µmol/L: 55% develop intracranial hypertension [7-8]
- Hemodynamic instability requiring vasopressors [5]
- Worsening coagulopathy (rising INR despite NAC) [5]
- Metabolic acidosis (pH <7.3) or arterial lactate >3.0 mmol/L (especially in acetaminophen ALF — part of King's College Criteria) [2-3]
- Renal failure (creatinine >3.4 mg/dL in acetaminophen ALF) [2]
- Hypoglycemia: Reflects loss of hepatic gluconeogenesis — requires continuous dextrose infusion [1]
- Fixed, dilated pupils: Suggests brainstem herniation — potential contraindication to transplant [9]
3. Medications
Etiology-specific treatments
- N-acetylcysteine (NAC) — the cornerstone of therapy:
- Acetaminophen ALF: IV preferred — 150 mg/kg load over 15–60 min, then 50 mg/kg over 4 h (12.5 mg/kg/h), then 100 mg/kg over 16 h (6.25 mg/kg/h); continue at 6.25 mg/kg/h until ALT is decreasing and INR <2 [3][6]
- Non-acetaminophen ALF: NAC improves transplant-free survival in grade 1–2 encephalopathy (52% vs. 30% with placebo); recommended by ACG and EASL guidelines [2-3][10]
- Activated charcoal: 1 g/kg (max 50 g) if within 4 hours of acetaminophen ingestion [3]
Medications to avoid or use with caution
- Do not prophylactically correct INR with FFP/platelets unless active bleeding or before high-risk procedures — hemostasis is "rebalanced" in ALF, and INR does not predict bleeding risk [3][11]
- Lactulose: May be used for grade 1–2 HE but should be discontinued in grade 3–4 (risk of bowel distension complicating transplant surgery) [3]
- Lactulose and rifaximin have not demonstrated benefit in ALF as they have in chronic liver disease [7]
- Vasopressin/terlipressin: May increase ICP — use with caution [8]
- Avoid hepatotoxic medications and adjust dosing for hepatic/renal impairment
Supportive medications
- PPI for stress ulcer prophylaxis [4]
- Norepinephrine as first-line vasopressor for fluid-refractory hypotension [2][11]
- Hypertonic saline (3%) to target serum Na 145–155 mEq/L for cerebral edema prophylaxis [2-3][7]
- Mannitol (0.5–1 g/kg) for acute ICP crises — but higher rebound ICP and AKI risk vs. hypertonic saline [2]
4. Diet
- NPO in patients with advanced encephalopathy or anticipated intubation/transplant
- Continuous dextrose infusion (D10W or D20W) to prevent hypoglycemia — monitor glucose every 1–2 hours [1]
- Avoid protein restriction — not evidence-based and may worsen catabolism
- Phosphorus replacement: Hypophosphatemia is a marker of hepatic regeneration (serum PO4 <2.5 mg/dL associated with 75% recovery rate); correct aggressively [2]
5. Review of Systems
- Neurologic: Confusion, somnolence, agitation, asterixis, coma — grade encephalopathy using West-Haven Criteria [3]
- GI: Nausea, vomiting, abdominal pain (RUQ), jaundice, GI bleeding
- Renal: Urine output, dark urine, oliguria (AKI occurs in ~50% of ALF)
- Respiratory: Dyspnea, tachypnea (respiratory alkalosis from hyperventilation is common early)
- Cardiovascular: Lightheadedness, syncope (vasodilatory shock)
- Hematologic: Easy bruising, mucosal bleeding, petechiae
- Infectious: Fever (absent in up to 30% of infected ALF patients), chills [3]
6. Collateral History and Family History
- Critical to obtain — patients are often encephalopathic and unable to provide history [3]
- Contact next of kin, pharmacy records, prescription monitoring databases [3]
- Ask about: empty pill bottles, suicide notes, access to medications, recent behavioral changes
- Family history: Wilson disease (autosomal recessive), alpha-1 antitrypsin deficiency, hereditary hemochromatosis, metabolic liver diseases
- Social context: Substance use, psychiatric history, prior suicide attempts (relevant to transplant candidacy) [12]
7. Risk Factors
- Acetaminophen use (accounts for ~50% of ALF in the US) — especially chronic use, fasting states, alcohol use, CYP2E1 inducers [3][13]
- Chronic alcohol consumption — worsens outcomes in ALF [3]
- Polypharmacy and herbal/dietary supplement use [3]
- Viral hepatitis exposure (hepatitis A, B, E; HSV, CMV, EBV) [3]
- Autoimmune conditions [3]
- Pregnancy (third trimester — AFLP, HELLP) [2]
- Malnutrition/fasting — depletes glutathione stores, increasing acetaminophen toxicity
- Ischemic/hypoxic injury (shock liver) — cardiac failure, sepsis, heat stroke [3]
8. Differential Diagnosis
- Acute-on-chronic liver failure (ACLF): Must distinguish from ALF — look for signs of chronic liver disease (spider angiomata, palmar erythema, splenomegaly) [3]
- Sepsis with secondary hepatic dysfunction: Can mimic ALF with coagulopathy and encephalopathy
- Ischemic hepatitis ("shock liver"): Very high AST/ALT (often >5,000), rapid rise and fall, history of hemodynamic compromise [8]
- Budd-Chiari syndrome: Hepatic vein thrombosis — ascites, hepatomegaly, abdominal pain
- Malignant infiltration: Lymphoma, metastatic disease — can present as ALF
- Heat stroke: Massive rhabdomyolysis with hepatic necrosis
- Wilson disease: Young patient, Coombs-negative hemolytic anemia, very high bilirubin with very low alkaline phosphatase (bilirubin/ALP ratio >2.0) [8]
- Autoimmune hepatitis: May present as ALF — check ANA, ASMA, IgG; low threshold for biopsy [8]
9. Past Medical History
- Prior liver disease, hepatitis, or abnormal LFTs
- Autoimmune conditions (autoimmune hepatitis, thyroid disease)
- Cardiac disease (ischemic hepatitis risk)
- Psychiatric history and prior suicide attempts (transplant candidacy) [12]
- Pregnancy history
- Prior transplant or immunosuppression
- Malignancy (may preclude transplant)
10. Physical Exam
- Vital signs: Hypotension (vasodilatory), tachycardia, tachypnea; fever may be absent despite infection [3]
- Mental status: Detailed neurologic exam — West-Haven grading of encephalopathy; pupillary reflexes (fixed dilated pupils = brainstem herniation) [2-3]
- Skin/eyes: Jaundice (may be minimal in hyperacute presentations), scleral icterus, excoriations
- Abdomen: RUQ tenderness, liver size (small/shrunken liver = massive necrosis or chronic disease), ascites, splenomegaly [3]
- Signs of chronic liver disease (should be absent in true ALF): Spider angiomata, palmar erythema, caput medusae, gynecomastia, Dupuytren contractures [3]
- Asterixis: Present in grade 2 HE
- Kayser-Fleischer rings: Slit-lamp exam if Wilson disease suspected
11. Lab Studies
Initial comprehensive panel: [2-3][14]
- Hepatic: AST, ALT, ALP, GGT, total/direct bilirubin, albumin
- Coagulation: PT/INR, aPTT, fibrinogen, Factor V level (Clichy criteria)
- Metabolic: BMP (glucose, creatinine, electrolytes), phosphate, magnesium, calcium, arterial lactate, ABG, ammonia (arterial preferred)
- Hematologic: CBC with differential, blood type and screen
- Viral serologies: Anti-HAV IgM, HBsAg, anti-HBc IgM, anti-HCV, anti-HEV IgM, HSV PCR, CMV PCR, EBV PCR
- Autoimmune: ANA, ASMA, anti-LKM, IgG levels
- Toxicology: Acetaminophen level, urine drug screen, ethanol level, acetaminophen-protein adducts (if available)
- Wilson disease workup: Ceruloplasmin, serum copper, 24-hour urine copper; bilirubin/ALP ratio >2.0 is a rapid bedside clue [8]
- Other: Lipase, pregnancy test, HIV, blood cultures, ferritin
Key lab pearls
- Very high AST/ALT with low bilirubin → think acetaminophen or ischemic hepatitis [8]
- Very high bilirubin with very low ALP → think Wilson disease [8]
- Ammonia >75 µmol/L → risk of HE; >200 µmol/L → high risk of intracranial hypertension [8]
- Hypophosphatemia → favorable sign of hepatic regeneration [2]
- INR does not predict bleeding risk — hemostasis is rebalanced [3]
12. Imaging
- Abdominal ultrasound with Doppler: First-line — assess liver size/echotexture, hepatic vein patency (rule out Budd-Chiari), portal vein flow, biliary dilation, ascites, signs of chronic liver disease [2-3]
- CT abdomen: If ultrasound is inconclusive; can assess liver volume (<1,000 cm³ associated with poor prognosis and regenerative failure) [2]
- Non-contrast CT head: For patients with grade 3–4 HE to evaluate for cerebral edema, intracranial hemorrhage [2]
- Chest X-ray: Baseline; evaluate for pulmonary edema, aspiration, ARDS
- Imaging pearl: A nodular liver on imaging may be overcalled as cirrhosis — a regenerating massively necrotic liver can mimic cirrhosis radiographically [3][8]
13. Special Tests
- King's College Criteria (KCC): Most widely used prognostic model; high specificity (93% for acetaminophen ALF) but limited sensitivity (~58%) [2-3]
- Acetaminophen: pH <7.3 (after resuscitation) OR all three of: INR >6.5, creatinine >3.4 mg/dL, grade 3–4 HE
- Non-acetaminophen: INR >6.5 OR any 3 of: age <10 or >40, unfavorable etiology, jaundice >7 days before HE, INR >3.5, bilirubin >17.5 mg/dL
- MELD score: More sensitive than KCC (77% vs. 61%); MELD ≥30.5 predicts need for transplant; better for non-acetaminophen ALF [2][10]
- Viscoelastic testing (TEG/ROTEM): Recommended by SCCM over INR for assessing true bleeding/thrombosis risk [3]
- Arterial ammonia: Independent predictor of intracranial hypertension [7-8]
- Acetaminophen-protein adducts: Research tool that can identify occult acetaminophen toxicity when history is unclear [8]
- Liver biopsy: Consider via transjugular route in indeterminate ALF — autoimmune hepatitis may be the largest category of "indeterminate" cases [8][10]
14. ECG
- QTc prolongation: Common in hepatic failure and identified as a key ECG biomarker [15]
- Sinus tachycardia: Reflects hyperdynamic circulation and vasodilatory state
- Arrhythmias: May occur secondary to electrolyte derangements (hypokalemia, hypomagnesemia, hypocalcemia)
- Troponin elevation: Present in 74% of ALF patients — subclinical myocardial injury is common and associated with increased mortality (OR 4.69 for death) [16]
- ECG indications: Baseline on all patients; monitor for arrhythmias, especially with electrolyte abnormalities and NAC infusion (telemetry recommended during IV NAC) [6]
15. Assessment
- ALF is classified by tempo: [3][5]
- Hyperacute (0–7 days): Acetaminophen, ischemia — highest cerebral edema risk but best spontaneous survival
- Acute (7–21 days): Viral hepatitis, drug reactions
- Subacute (>21 days to 26 weeks): Indeterminate, Wilson disease, autoimmune — lowest cerebral edema risk but worst prognosis without transplant
- Etiology is the most important predictor of spontaneous recovery: acetaminophen, hepatitis A, pregnancy-related, and ischemic liver injury have the highest likelihood of spontaneous survival [13]
- SIRS is a hallmark of ALF and drives cerebral edema and multiorgan dysfunction [2]
- Complications to anticipate: cerebral edema/intracranial hypertension, AKI (~50%), sepsis, coagulopathy, cardiovascular collapse, ARDS, hypoglycemia, adrenal insufficiency [1][5]
16. Treatment Plan
Initial stabilization
- ABCs — intubate for grade 3–4 HE for airway protection [3][11]
- Volume resuscitation with balanced crystalloids; avoid hypervolemia and hypovolemia [2]
- Continuous glucose monitoring; D10W infusion to prevent hypoglycemia
- Head of bed elevation to 30°; minimize stimulation
Etiology-specific treatment
- Acetaminophen: NAC (see dosing above); activated charcoal if within 4 hours [3][6]
- Mushroom poisoning (Amanita): Silibinin (if available), NAC, consider charcoal [4]
- Wilson disease: CRRT, consider plasma exchange; emergent transplant evaluation [4][8]
- Autoimmune hepatitis: Corticosteroids (methylprednisolone 1 mg/kg) — may be effective; low threshold for biopsy [3]
- HSV hepatitis: IV acyclovir
- Hepatitis B reactivation: Nucleos(t)ide analogue (entecavir or tenofovir)
Cerebral edema management: [2-3][7]
- Hypertonic saline (3%) to target Na 145–155 mEq/L (prophylactic in grade 3–4 HE)
- Mannitol 0.5–1 g/kg for acute ICP surges
- CRRT — first-line for hyperammonemia; used even without AKI [3][7]
- High-volume plasma exchange (HVPE) — improved transplant-free survival in one RCT [7]
- Avoid hyperthermia; target normothermia
Infection management: [3][11]
- Regular surveillance cultures (blood, urine, sputum)
- Empiric antibiotics and antifungals in the setting of clinical deterioration, SIRS, or worsening encephalopathy
- Routine antimicrobial prophylaxis is not supported by evidence in well-resourced settings [3]
Coagulopathy: [3][11]
- Do not correct INR prophylactically — overt bleeding is uncommon (~5% of deaths)
- Correct only before high-risk invasive procedures (e.g., ICP monitor placement) with FFP, cryoprecipitate, platelets, or rFVIIa as needed
- Use viscoelastic testing (TEG/ROTEM) to guide transfusion decisions [3]
17. Disposition
- All patients with ALF require ICU admission [1-3]
- Grade 2 HE → transfer to ICU; Grade 3–4 HE → intubation [3]
- All patients should be referred to a liver transplant center — the AASLD recommends this as a strong recommendation [12]
- Referral should occur within the first few hours of presentation, ideally before meeting full ALF diagnostic criteria, as patients may deteriorate rapidly during transfer [12]
- UNOS Status 1a listing criteria: ICU care + one of: ventilator dependence, renal replacement therapy, or INR ≥2 with HE onset within 8 weeks of initial symptoms [2][13]
- Approximately one-third of ALF patients recover spontaneously, one-third undergo transplant, and one-third die [12]
- 1-year post-transplant survival: 84% in the US, 79% in Europe [3]
18. Follow Up / Return Precautions
- For survivors discharged after spontaneous recovery:
- Hepatology follow-up within 1–2 weeks
- Serial LFTs to confirm normalization
- Repeat coagulation studies
- Psychiatric evaluation if intentional overdose [12]
- Substance use counseling if applicable
- Return precautions: Worsening jaundice, confusion/altered mental status, persistent vomiting, dark urine, abdominal swelling, bleeding, fever
- Expected recovery: Acetaminophen and ischemic ALF may recover within days to weeks; subacute etiologies have a more protracted course
- Long-term considerations: Patients who undergo transplant require lifelong immunosuppression, monitoring for rejection, and cancer screening [2-3]
References
1. Acute Liver Failure: A Review for Emergency Physicians. — Montrief T, Koyfman A, Long B. The American Journal of Emergency Medicine. 2019.
2. Acute Liver Failure. — Maiwall R, Kulkarni AV, Arab JP, Piano S. Lancet. 2024.
3. Acute Liver Failure Guidelines. — Shingina A, Mukhtar N, Wakim-Fleming J, et al. The American Journal of Gastroenterology. 2023.
4. Acute liver failure. — William M. Lee Yamada's Textbook of Gastroenterology 7e. 2022.
5. Management of Acute Liver Failure: Update 2022. — Tujios S, Stravitz RT, Lee WM. Seminars in Liver Disease. 2022.
6. AASLD Practice Guidance on Drug, Herbal, and Dietary Supplement-Induced Liver Injury. — Fontana RJ, Liou I, Reuben A, et al. Hepatology. 2023.
7. Guidelines for the Management of Adult Acute and Acute-on-Chronic Liver Failure in the ICU: Neurology, Peri-Transplant Medicine, Infectious Disease, and Gastroenterology Considerations. — Nanchal R, Subramanian R, Alhazzani W, et al. Critical Care Medicine. 2023.
8. Introduction to the Revised American Association for the Study of Liver Diseases Position Paper on Acute Liver Failure 2011. — Lee WM, Stravitz RT, Larson AM. Hepatology. 2012.
9. Acute Liver Failure: Prognosis and Management. — Jennifer Price, Brian J. Hogan, Banwari Agarwal Evidence‐based Gastroenterology and Hepatology 4e. 2019.
10. American Gastroenterological Association Institute Guidelines for the Diagnosis and Management of Acute Liver Failure. — Flamm SL, Yang YX, Singh S, Falck-Ytter YT. Gastroenterology. 2017.
11. Acute Liver Failure. — Bernal W, Wendon J. The New England Journal of Medicine. 2013.
12. AASLD AST Practice Guideline on Adult Liver Transplantation: Candidate Evaluation. — Dove L, Chadha RM, Lai JC, et al. Hepatology. 2025.
13. Evaluation for Liver Transplantation in Adults: 2013 Practice Guideline by the American Association for the Study of Liver Diseases and the American Society of Transplantation. — Martin P, DiMartini A, Feng S, Brown R, Fallon M. Hepatology. 2014.
14. Advances in Medical Management of Acute Liver Failure in Children: Promoting Native Liver Survival. — Deep A, Alexander EC, Bulut Y, et al. The Lancet. Child & Adolescent Health. 2022.
15. Electrocardiogram-Based Diagnosis of Liver Diseases: An Externally Validated and Explainable Machine Learning Approach. — Lopez Alcaraz JM, Haverkamp W, Strodthoff N. EClinicalMedicine. 2025.
16. Elevated Troponin I Levels in Acute Liver Failure: Is Myocardial Injury an Integral Part of Acute Liver Failure?. — Parekh NK, Hynan LS, De Lemos J, Lee WM. Hepatology. 2007.