How should acute liver failure be evaluated and managed, including cause‑specific therapy, supportive care, and transplant assessment?

Acute Liver Failure: Evaluation and Management

Immediate Recognition and ICU Admission

All patients with acute liver failure (defined as INR ≥1.5 plus any degree of hepatic encephalopathy in a patient without pre-existing cirrhosis, with illness duration ≤26 weeks) must be admitted immediately to an intensive care unit and a liver transplant center contacted within hours of diagnosis. 1, 2

The clinical window for intervention is extremely narrow—patients can deteriorate hour-by-hour, and early transplant referral is non-negotiable because the "transplantation window" closes rapidly 1, 2.

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Initial Diagnostic Evaluation

Essential Laboratory Tests (Obtain Immediately)

• Coagulation panel: PT/INR (diagnostic threshold INR ≥1.5) 1, 2
• Acetaminophen level: Measure in all patients regardless of history, as occult toxicity is common 1, 2
• Comprehensive metabolic panel: Including glucose (hypoglycemia is frequent), electrolytes, creatinine, and liver enzymes 1, 2
• Arterial blood gas and lactate: Elevated lactate and arterial pH <7.3 are critical prognostic markers 1
• Viral serologies: Anti-HAV IgM, HBsAg, anti-HBc IgM, anti-HCV 1, 2
• Toxicology screen: Urine amphetamine, cocaine 1
• Ceruloplasmin and 24-hour urine copper: In all patients ≤40 years to exclude Wilson disease 2
• Autoimmune markers: ANA, ASMA, IgG if autoimmune hepatitis suspected 2
• Pregnancy test: In all women of childbearing age 2
• Ammonia level: Arterial ammonia >100–150 µmol/L predicts intracranial hypertension risk 2

Imaging Studies

• Hepatic Doppler ultrasound: Mandatory to exclude Budd-Chiari syndrome and assess hepatic vasculature 1, 2
• Echocardiography: To identify cardiac dysfunction in suspected ischemic ("shock") hepatitis 1, 2
• Transjugular liver biopsy: Consider when etiology remains unclear after initial workup, particularly for suspected autoimmune hepatitis—safer than percutaneous approach in coagulopathic patients 1, 2

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Cause-Specific Therapy

Acetaminophen Toxicity

• N-acetylcysteine (NAC): Administer immediately—140 mg/kg orally or via nasogastric tube, followed by 70 mg/kg every 4 hours for 17 doses 2
• Continue NAC even if >48 hours since ingestion 2
• Activated charcoal: 1 g/kg orally if presentation within 4 hours of ingestion, given just prior to NAC 2
• Systematic NAC administration is recommended whatever the suspected etiology (not just acetaminophen) 1

Viral Hepatitis

• Hepatitis A and B: No virus-specific treatment proven effective; supportive care only 2
• Herpes simplex virus or varicella zoster: Immediate acyclovir and urgent transplant listing 1, 2
• For patients requiring chemotherapy/immunosuppression with hepatitis B: nucleoside analogs before and for 6 months after treatment 2

Autoimmune Hepatitis

• Liver biopsy (transjugular route): To confirm diagnosis 2
• Prednisone 40–60 mg/day: Start immediately 2
• List for transplantation even while administering corticosteroids—do not delay listing 2

Wilson Disease

• Uniformly fatal without transplantation—list immediately 2
• Plasmapheresis, albumin dialysis, continuous hemofiltration, or plasma exchange: To acutely lower serum copper and limit hemolysis 2
• Do NOT use penicillamine in ALF due to hypersensitivity risk 2

Pregnancy-Related (Acute Fatty Liver/HELLP)

• Expeditious delivery with obstetrical consultation: This is definitive treatment 2
• Recovery is typically rapid after delivery with supportive care only 2

Drug-Induced Hepatotoxicity

• Discontinue all non-essential medications 2
• Obtain detailed medication history including prescription drugs, over-the-counter medications, herbs, and dietary supplements 2

Mushroom Poisoning

• Penicillin G and silymarin: Consider administration 2
• List for transplantation immediately—often the only lifesaving option 2

Ischemic ("Shock") Hepatitis

• Cardiovascular support is the treatment of choice; transplantation seldom indicated 2

Budd-Chiari Syndrome

• Transplantation indicated if significant liver failure present 2
• Exclude underlying malignancy before transplantation 2

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Supportive Care Management

Central Nervous System and Encephalopathy

Grade I–II Encephalopathy:

• Frequent mental status checks; transfer to ICU if consciousness declines 1, 2
• Minimize stimulation; avoid sedation if possible 1
• Elevate head of bed to 30 degrees 2
• Lactulose: Possibly helpful to reduce ammonia levels, though evidence for improved outcomes is limited 1, 2
• Surveillance and treatment of infection required; prophylaxis possibly helpful 1

Grade III–IV Encephalopathy (Cerebral Edema Risk 65–75%):

• Intubate for airway protection (may require sedation with propofol—avoid benzodiazepines as they worsen encephalopathy) 1, 2
• Maintain serum sodium 140–145 mmol/L; hypertonic saline infusion can significantly decrease intracranial pressure 2
• Consider ICP monitoring device placement 1
• Mannitol: Use for severe ICP elevation or first clinical signs of herniation 1
• Hyperventilation: Effects short-lived; reserve for impending herniation 1
• Control seizures with phenytoin; add diazepam only as needed; prophylaxis of unclear value 1, 2
• Do NOT use lactulose or rifaximin to lower ammonia levels 1
• Do NOT administer benzodiazepines or psychotropic drugs (such as metoclopramide) 1

Hemodynamic Management

• Maintain mean arterial pressure ≥50–60 mm Hg through aggressive fluid resuscitation first 1, 2
• Fluid resuscitation: Colloid (albumin) preferred over crystalloid; all solutions should contain dextrose to maintain euglycemia 2
• Pulmonary artery catheterization: Consider in hemodynamically unstable patients 1, 2
• Vasopressors if fluid replacement fails: Epinephrine, norepinephrine, or dopamine (dopamine associated with increased systemic oxygen delivery in ALF) 1, 2
• Do NOT use vasopressin—potentially harmful in ALF 1, 2

Coagulation Management

• Vitamin K: Give at least one dose 1
• Fresh frozen plasma (FFP): Reserve for invasive procedures or active bleeding only—do NOT correct INR prophylactically 1, 2
• Most ALF patients have rebalanced hemostasis between pro- and anticoagulant factors; bleeding complications occur in only 10% 2
• Platelets: Give for counts <10,000/mm³ or before invasive procedures 1
• Recombinant activated factor VII: Possibly effective for invasive procedures 1
• Do NOT routinely correct coagulation—restrict clotting factor administration unless active bleeding 1

Renal Support

• Continuous renal replacement therapy (CRRT): Preferred over intermittent hemodialysis if dialysis needed 1, 2
• Avoid nephrotoxic agents including NSAIDs 1
• Regional citrate anticoagulation should be monitored due to potential metabolic effects in ALF 2

Metabolic Management

• Monitor blood glucose at least every 2 hours; manage hypoglycemia with continuous glucose infusions 1, 2
• Monitor and supplement: Phosphate, magnesium, potassium as needed 1, 2

Nutritional Support

• Initiate enteral feedings early with moderate protein intake (approximately 60 grams per day) 1, 2
• Avoid severe protein restrictions—branched-chain amino acids have not been shown superior to other enteral preparations 2
• If enteral feedings contraindicated, parenteral nutrition is an option despite risks of fungal infection 1, 2

Infection Prevention and Management

• Surveillance for and prompt antimicrobial treatment of infection required 1
• Empirical broad-spectrum antibiotics: Administer to patients with worsening hepatic encephalopathy or signs of SIRS 1
• Antibiotic prophylaxis possibly helpful but not proven 1
• Stress ulcer prophylaxis: H2 blocker or proton pump inhibitor 1, 2

Respiratory Support

• Standard lung protective ventilator strategy according to specific recommendations 1
• Avoid high PEEP (>10 cmH₂O) due to risk of hepatic congestion 2

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Prognostic Assessment and Transplant Listing

King's College Criteria (Best Prognostic Tool, Though Sensitivity Limited 50–60%)

Acetaminophen-induced ALF—poor prognosis if:

• Arterial pH <7.3 after resuscitation OR
• All three: INR >6.5, creatinine >300 µmol/L (3.4 mg/dL), and grade 3–4 encephalopathy 1, 2

Non-acetaminophen ALF—poor prognosis if:

• INR >6.5 OR
• Any three of: age <10 or >40 years, non-A/non-B hepatitis, drug-induced injury, jaundice >7 days before encephalopathy, INR >3.5, bilirubin >300 µmol/L (17.5 mg/dL) 1, 2

Additional Poor Prognostic Indicators

• Idiosyncratic drug injury, non-hepatitis A viral infections, autoimmune hepatitis, mushroom poisoning, Wilson disease, Budd-Chiari syndrome, indeterminate cause 2
• Factor V activity <20% (Clichy-Villejuif criteria) 2
• Requirement for vasopressor support 2
• Grade 3–4 encephalopathy: Associated with only ~33% short-term survival without transplantation 2

Transplant Listing

• Urgent hepatic transplantation indicated when prognostic indicators suggest high likelihood of death 1, 2
• List patients early in the course of ALF—do not wait for maximal deterioration 2
• Post-transplant survival rates: 80–90% even in patients with multiple organ failures 2
• One-year survival with transplantation: 79% (Europe 1995), with experienced centers achieving >85% 1

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Artificial Liver Support Systems

• No certain evidence of efficacy for various liver support systems 2
• MARS and Prometheus systems: Do NOT improve 28-day or 90-day survival in randomized controlled trials 2
• Sorbent systems: May show transient improvement of hepatic encephalopathy but no improvement in hepatic function or long-term benefit 2
• Porcine hepatocyte-based bioartificial liver: Recent studies show improved short-term survival for some patients, but further research needed 2
• Plasmapheresis: May stabilize patients and serve as bridging therapy until transplantation, particularly in Wilson disease to protect kidneys from copper-mediated tubular damage 2

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Critical Pitfalls to Avoid

• Do NOT delay transplant referral—contact within hours, not days 1, 2
• Do NOT correct INR prophylactically—ALF exhibits "rebalanced" hemostasis; FFP only for bleeding or procedures 1, 2
• Do NOT use benzodiazepines—they worsen encephalopathy 1, 2
• Do NOT use vasopressin—potentially harmful in ALF 1, 2
• Do NOT restrict protein severely—moderate intake (60 g/day) is appropriate 2
• Do NOT miss acetaminophen toxicity—measure level in all patients regardless of history 1, 2
• Do NOT use penicillamine in Wilson disease-related ALF—risk of hypersensitivity 2
• Do NOT delay delivery in pregnancy-related ALF—expeditious delivery is definitive treatment 2