Hepatic encephalopathy and acute liver failure

Also known as Hepatic encephalopathy (HE) · Acute liver failure (ALF) · West Haven classification · Acute-on-chronic liver failure (ACLF) · King's College Criteria

Hepatic encephalopathy is a reversible spectrum of neuropsychiatric abnormalities in patients with liver dysfunction, classified by the West Haven system (Grade I-IV). Pathophysiology centres on ammonia-induced astrocyte swelling and systemic inflammation. Precipitating factors include infection, GI bleed, constipation, sedatives, and electrolyte disturbance. Management: lactulose (first-line), rifaximin (add-on), treat precipitant, avoid sedatives, protein restriction NOT recommended. Acute liver failure (ALF) is a separate entity with different management priorities: N-acetylcysteine (improves survival in non-acetaminophen ALF), intracranial pressure management, and liver transplant listing using King's College Criteria.

high18 referencesUpdated 26 July 202615 min readSource-verified · Sept 2026

Checked against its sources on 3 Sept 2026

In one line

Hepatic encephalopathy (HE) is a spectrum of neuropsychiatric abnormalities in liver disease, graded by the West Haven scale from subclinical change to coma.^[1] Pathophysiology centres on ammonia and nitrogen metabolism interacting with systemic inflammation.^[4] Precipitants include infection, GI bleeding, constipation, sedatives, and electrolyte disturbance such as hyponatraemia.^[9] Management: treat the precipitant, then lactulose (non-absorbable disaccharide) first-line, rifaximin 550 mg twice daily as an add-on for recurrent HE, and do not restrict protein (target 1.2 to 1.5 g per kg per day).^[8]^[9] Acute liver failure (ALF) is a separate entity without prior liver disease: N-acetylcysteine improves transplant-free survival in early-stage non-acetaminophen ALF, intracranial pressure control is central, and transplant listing uses the King's College Criteria.^[5]^[11]

Meet the patient

A 58-year-old man with known alcoholic cirrhosis arrives confused and drowsy, GCS 12, with ascites and asterixis. He has a fever of 38.3, heart rate 105, blood pressure 100 over 60, sodium 128, potassium 3.1, INR 2.1. An ascitic tap shows 350 neutrophils per cubic millimetre. The single decision that frames everything else is what pushed him over — and the answer here is hiding in the ascitic fluid.^[1]

Spontaneous bacterial peritonitis is the number-one precipitant of HE in cirrhosis, and it is frequently silent. Tap every cirrhotic with ascites and new confusion, start empiric antibiotics after cultures, and the encephalopathy usually lifts with the infection. Hold that instinct — hunt the precipitant before you reach for the ammonia-lowering drugs.^[1]

References18Show

[1]Dellatore P, Cheung M, Mahpour NY, et al. Clinical Manifestations of Hepatic Encephalopathy Clin Liver Dis, 2020.PMID 32245526
[2]Rose CF, Amodio P, Bajaj JS, et al. Hepatic encephalopathy: Novel insights into classification, pathophysiology and therapy J Hepatol, 2020.PMID 33097308
[3]Zacharias HD, Kamel F, Tan J, et al. Rifaximin for prevention and treatment of hepatic encephalopathy in people with cirrhosis Cochrane Database Syst Rev, 2023.PMID 37467180
[4]Said VJ, Garcia-Trujillo E Beyond Lactulose: Treatment Options for Hepatic Encephalopathy Gastroenterol Nurs, 2019.PMID 31145253
[5]Lee WM, Hynan LS, Rossaro L, et al. Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure Gastroenterology, 2009.PMID 19524577
[6]EASL Clinical Practice Guidelines. EASL Clinical Practice Guidelines on acute-on-chronic liver failure J Hepatol, 2023.PMID 37364789
[7]Sarin SK, Choudhury AK, Sharma MK, et al. Acute-on-chronic liver failure (ACLF): the 'Kyoto Consensus'-steps from Asia Hepatol Int, 2025.PMID 39961976
[8]Bass NM, Mullen KD, Sanyal A, et al. Rifaximin treatment in hepatic encephalopathy N Engl J Med, 2010.PMID 20335583
[9]Amodio P, Bemeur C, Butterworth R, et al. The nutritional management of hepatic encephalopathy in patients with cirrhosis: International Society for Hepatic Encephalopathy and Nitrogen Metabolism Consensus Hepatology, 2013.PMID 23471642
[10]Flamm SL, Wong F, Ahn J, Kamath PS AGA Clinical Practice Update on the Evaluation and Management of Acute Kidney Injury in Patients With Cirrhosis: Expert Review Clin Gastroenterol Hepatol, 2022.PMID 36075500
[11]O'Grady JG, Alexander GJ, Hayllar KM, Williams R Early indicators of prognosis in fulminant hepatic failure Gastroenterology, 1989.PMID 2490426
[12]Long B, Gottlieb M Emergency medicine updates: Spontaneous bacterial peritonitis Am J Emerg Med, 2023.PMID 37244043
[13]Shehata HH, Elfert AA, Abdin AA, et al. Randomized controlled trial of polyethylene glycol versus lactulose for the treatment of overt hepatic encephalopathy Eur J Gastroenterol Hepatol, 2018.PMID 30234645
[14]Ansari N, Wadhawan M Evaluation and management of neurological complications in acute liver failure Best Pract Res Clin Gastroenterol, 2024.PMID 39709217
[15]Nagesh VK, Martinez E, Badam S, et al. Management of acute liver failure-an updated literature review World J Crit Care Med, 2025.PMID 41377535
[16]Glass KA, Stoecker ZR, LeRoy J, et al. Investigating a Novel Two-Bag N-Acetylcysteine Regimen for Acetaminophen Toxicity J Med Toxicol, 2024.PMID 38992233
[17]Friis KH, Thomsen KL, Laleman W, et al. Post-Transjugular Intrahepatic Portosystemic Shunt (TIPS) Hepatic Encephalopathy-A Review of the Past Decade's Literature Focusing on Incidence, Risk Factors, and Prophylaxis J Clin Med, 2023.PMID 38202028
[18]Ahmed Z, Badal J, Gangwani MK, et al. Sarcopenia is a risk factor for post-transjugular intrahepatic portosystemic shunt hepatic encephalopathy and mortality: A systematic review and meta-analysis Indian J Gastroenterol, 2024.PMID 38085501