Hepatic Encephalopathy: Best Practice and Management

Hepatic Encephalopathy: Best Practice and Management

Summary of Lecture by Prof. Jasmohan Bajaj

1. Main Clinical Topics Discussed

• Definition and updated classification of hepatic encephalopathy (HE)
• Pathophysiology with emphasis on the gut-brain axis and microbiome
• Clinical grading systems (West Haven Criteria, covert vs. overt HE)
• Inpatient management and prevention of recurrence
• Role of multidisciplinary care
• Emerging diagnostic and therapeutic strategies

2. Key Learning Points, Guidelines, and Recommendations

Definition (EASL CPG, updated 2023; originally proposed 2014):

• HE is defined as *brain dysfunction caused by liver insufficiency and/or portosystemic shunting*
• Manifests across a spectrum from subclinical alterations to coma
• Cirrhosis is not a prerequisite — congenital or acquired portosystemic shunts alone can be sufficient
• Neuropsychiatric abnormalities, including subclinical ones, are valid presentations

Classification — Four Axes:

• Type: A (acute liver failure), B (bypass/portosystemic shunts), C (cirrhosis — most common)
• Grade:

- Minimal HE + Grade 1 → pragmatically reclassified as Covert HE (distinction between grades 1 and 2 is poorly reproducible)

- Grades 2–4 = Overt HE (confusion with asterixis → stupor/lethargy → coma)

- FDA and EMA endorse this covert/overt distinction for clinical trial design

• Time Course: Episodic vs. recurrent (further episodes within 6 months)
• Precipitating Factors: Must be identified and documented; recurrence due to the same precipitant demands targeted intervention

Recommended Charting Practice:

• Document all four axes (e.g., *"Grade 3, Type C, Recurrent, Precipitating Factor: GI bleed"*) to facilitate consistent care planning and prevent recurrence

Multidisciplinary Care Model:

• HE management requires a "village" approach including:

- Hepatology/GI, Hospital Medicine, Interventional Radiology

- Nutrition, Physical Therapy, Mental Health/Substance Abuse

- Social Work, Advanced Practice Providers, Transplant Team

- Family members and caregivers as active participants

3. Specific Clinical Data, Statistics, and Study Results Cited

Epidemiology & Burden:

• HE is now the #1 decompensating event in NAFLD-related cirrhosis
• Independently associated with high mortality
• Number one cause of preventable hospital readmissions
• Increases caregiver burden significantly
• Patients with HE are not prioritized for liver transplantation despite high disease burden

Microbiome Research (Bajaj et al., 2016 — Germ-Free Mouse Model):

• Germ-free cirrhotic mice showed elevated ammonia (via intestinal glutaminase activity) but did not develop neuroinflammation (elevated IL-1β, MCP-1, IBA-1, GFAP)
• Confirms: ammonia alone is insufficient to cause HE — active gut microbiota are required
• Transplanting stool from cirrhotic humans into germ-free mice induced higher neuroinflammation compared to stool from healthy controls, demonstrating that microbiota composition (not mere presence) drives HE pathophysiology
• Supernatant alone (without live bacteria) had no inflammatory effect — live, active bacteria are necessary

Streptococcus and Rifaximin:

• *Streptococcus* spp. produce urease → convert urea to ammonia → clinically significant ammonia source
• In patients with minimal HE treated with rifaximin, dense microbial correlations involving *Streptococcus salivarius* and *S. faecalis* were markedly disrupted post-treatment — suggesting this is a key mechanism of rifaximin's action

Salivary and Stool Microbiome:

• Microbi