Hepatic encephalopathy
Hepatic encephalopathy is a reversible spectrum of brain dysfunction from insufficient hepatic clearance and portosystemic shunting of gut-derived toxins, graded by the West Haven criteria and almost always triggered by an identifiable precipitant such as infection, gastrointestinal bleeding, constipation, or an electrolyte disturbance. Diagnosis is clinical, and management proceeds by treating the precipitant first, then titrating lactulose and adding rifaximin for recurrence prevention.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Definition: hepatic encephalopathy (HE) is brain dysfunction ranging from minimal, subclinical abnormalities to frank coma, caused by insufficient hepatic clearance of gut-derived toxins together…
- Epidemiology
Tied to decompensated cirrhosis: HE is one of the defining complications of decompensated cirrhosis, alongside ascites and variceal hemorrhage, and should prompt referral for liver transplant evaluation.
- Risk factors
Cirrhosis with portal hypertension: the dominant substrate, from any cause of chronic liver disease.
- Pathophysiology
Failure of hepatic clearance: insufficient hepatic metabolic function fails to detoxify nitrogenous compounds, chiefly ammonia, absorbed from the gut.
- Clinical features
This is a clinical diagnosis established at the bedside, graded by the West Haven criteria: Minimal: no clinical signs of encephalopathy (no confusion, no asterixis); detected only on formal neuropsychiatric or psychometric testing.
- Differential diagnosis
Alcohol intoxication or withdrawal: altered sensorium with tremor and autonomic hyperactivity, and possible seizures, rather than asterixis.
- Diagnosis
This is a clinical diagnosis: recognize the West Haven grade in a patient with known or suspected liver disease, then search for and confirm the precipitant.
- Management
Ensure airway safety first: in grade 3 or 4 disease with diminished consciousness or loss of airway-protective reflexes, admit to an ICU and evaluate for intubation, and protect the airway before any enteral medication.
- Complications
Cerebral edema: most feared in acute liver failure, where progressive encephalopathy can advance to raised intracranial pressure.
- Prognosis
Marker of decompensation: an episode of overt HE identifies decompensated cirrhosis and a substantially worse prognosis than compensated disease.
- Prevention
Secondary prophylaxis with lactulose: continue lactulose after recovery from the first episode, titrated to 2 to 3 soft stools daily, indefinitely.
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Cirrhosis
Cirrhosis is end-stage hepatic fibrosis with regenerative nodules, staged as compensated or decompensated by the onset of ascites, variceal hemorrhage, encephalopathy, or jaundice. Severity is graded by Child-Pugh class and MELD, and management centers on treating the underlying cause, surveillance for varices and hepatocellular carcinoma, and timely transplant referral once decompensation appears.
- Portal hypertension
Portal hypertension is elevated pressure in the portal venous system, most often from cirrhosis, that drives the major decompensating complications of chronic liver disease: varices, ascites, splenomegaly, and encephalopathy. Diagnosis rests on imaging and endoscopy for its downstream signs, and management combines treating the underlying cause with nonselective beta-blockade and, for refractory complications, TIPS.
- Cirrhotic ascites
Cirrhotic ascites is fluid accumulation in the peritoneal cavity driven by portal hypertension and splanchnic vasodilation, confirmed by a serum-ascites albumin gradient of 1.1 g/dL or more on diagnostic paracentesis. Management proceeds from sodium restriction and combination diuretics to large-volume paracentesis with albumin and TIPS for refractory disease, with every new or worsening episode screened for spontaneous bacterial peritonitis.
- Spontaneous bacterial peritonitis
Spontaneous bacterial peritonitis is a monomicrobial infection of cirrhotic ascitic fluid without a surgical source, diagnosed by an ascitic fluid neutrophil count of 250 cells/microL or higher on paracentesis. Treatment is prompt IV third-generation cephalosporin plus IV albumin in patients with renal or hepatic dysfunction, followed by indefinite secondary antibiotic prophylaxis because recurrence is common.
- Hepatorenal syndrome
Hepatorenal syndrome is functional renal failure in a patient with cirrhosis and ascites, driven by splanchnic vasodilation and compensatory renal vasoconstriction, and it is diagnosed only after excluding shock, nephrotoxins, and structural kidney disease and after creatinine fails to improve with diuretic withdrawal and an albumin challenge. Treatment is a splanchnic vasoconstrictor (terlipressin first-line) with intravenous albumin as a bridge to liver transplantation, the only curative therapy.
- Acute upper gastrointestinal bleeding
Acute upper gastrointestinal bleeding arises proximal to the ligament of Treitz and presents with hematemesis or melena, most often from peptic ulcer disease or bleeding gastroesophageal varices. Management sequences resuscitation, restrictive transfusion, IV proton pump inhibitor therapy, and, when varices are suspected, octreotide plus antibiotic prophylaxis, all before upper endoscopy within 24 hours, which is both diagnostic and therapeutic.
- Acute liver failure
Acute liver failure is the abrupt onset of hepatic synthetic dysfunction, defined by coagulopathy with an INR of 1.5 or higher plus any grade of hepatic encephalopathy, occurring within 26 weeks of illness onset in a patient without preexisting liver disease. Acetaminophen overdose is the leading cause in the United States, and management centers on N-acetylcysteine when acetaminophen is implicated, intensive supportive care, and early referral to a liver transplant center.