What is the likely cause of altered mental status in an elderly patient with elevated liver enzymes, hyperammonemia, and abdominal distention, taking medications including Atorvastatin (Atorvastatin Calcium), Amiodarone, and Lactulose?

Hepatic Encephalopathy from Hyperammonemia

The altered mental status in this elderly patient is most likely caused by hepatic encephalopathy precipitated by multiple factors including abdominal distention/ileus (which impairs lactulose effectiveness), potential hepatotoxic medications (amiodarone, atorvastatin, hydrocodone-acetaminophen), and possibly infection given the constellation of elevated liver enzymes and ammonia level of 195. 1

Primary Diagnosis: Hepatic Encephalopathy

The clinical presentation of lethargy with preserved orientation, elevated ammonia (195), elevated liver enzymes, and abdominal distention is classic for hepatic encephalopathy, likely Grade 2 on the West Haven criteria (lethargy, mild disorientation, inappropriate behavior). 1, 2

Key Precipitating Factors to Address

Abdominal distention/ileus is critically important because:

• It prevents oral lactulose from working effectively 1
• The patient is already on lactulose, suggesting it may not be reaching the colon due to ileus 1
• This creates a vicious cycle where ammonia cannot be eliminated 1

Medication-induced hepatotoxicity is highly probable given:

• Amiodarone: Well-known hepatotoxin that can cause elevated transaminases and alkaline phosphatase 2
• Atorvastatin: Can cause hepatotoxicity, especially in elderly patients 2
• Hydrocodone-acetaminophen: Acetaminophen hepatotoxicity risk, particularly concerning with elevated liver enzymes 3
• Alprazolam: Benzodiazepines are contraindicated in hepatic encephalopathy as they precipitate and worsen encephalopathy 2

Other precipitating factors to investigate 1, 2:

• Infection (empiric antibiotics reasonable given high-risk presentation)
• Electrolyte disorders (hyponatremia particularly important—maintain Na >130 mmol/L)
• Dehydration from lactulose overuse
• Constipation despite lactulose (paradoxical if underdosed)
• GI bleeding (though not mentioned, should be excluded)

Immediate Management Algorithm

Step 1: Airway Assessment

• This patient is alert and oriented, so intubation is not indicated 4
• Transfer to monitored setting to prevent aspiration and falls 2

Step 2: Modify Lactulose Administration for Ileus

Since abdominal distention is present, oral lactulose is likely ineffective 1:

• Switch to lactulose enema (300 mL lactulose in 700 mL water for total 1 L) 1, 2
• Alternatively, consider polyethylene glycol if patient is at risk of ileus/abdominal distention 1, 2
• Hold oral lactulose until ileus resolves 1

Step 3: Discontinue Hepatotoxic and Encephalopathy-Precipitating Medications

Immediately discontinue 2:

• Alprazolam (benzodiazepines contraindicated—precipitate HE)
• Hydrocodone-acetaminophen (consider acetaminophen toxicity; switch to acetaminophen alone at 2-3 g/day maximum if pain control needed)
• Consider holding amiodarone and atorvastatin temporarily until liver function stabilizes

Review and minimize 2:

• Omeprazole (discontinue unless strictly necessary—can precipitate HE)
• Ondansetron, dicyclomine (anticholinergic effects may worsen mental status)

Step 4: Investigate and Treat Precipitating Factors

Mandatory workup 1, 2:

• Blood cultures, urinalysis, chest X-ray (rule out infection)
• Complete metabolic panel with focus on sodium (maintain >130 mmol/L), potassium, magnesium
• Assess for GI bleeding (stool guaiac, hemoglobin trend)
• Evaluate volume status and treat dehydration if present

Empiric antibiotics are reasonable given high-risk presentation with altered mental status and elevated ammonia 1

Step 5: Sedation Management if Needed

If agitation requires sedation 2:

• Use dexmedetomidine (short-acting, preserves cognitive function)
• Avoid all benzodiazepines (contraindicated)
• Minimize opioids but provide adequate pain control

Alternative Diagnoses to Consider

While hepatic encephalopathy is most likely, a low ammonia level would point toward other etiologies 1:

• Drug intoxication/withdrawal (alcohol, benzodiazepines)
• Structural brain injury (consider brain imaging if first episode, seizures, focal signs, or inadequate response to therapy) 1, 2
• Primary psychiatric disorder
• Metabolic encephalopathy from other causes

Brain imaging is NOT routinely indicated unless this is the first episode, there are seizures/focal neurological signs, or inadequate response to therapy 1, 2

Critical Pitfalls to Avoid

• Do not rely on ammonia levels for diagnosis or monitoring—they are variable and can be elevated in non-HE conditions 1
• Do not continue oral lactulose in the setting of ileus/abdominal distention—it will not work and may worsen distention 1
• Do not use benzodiazepines for sedation—they have synergistic negative impact on HE 2
• Do not attribute all altered mental status to HE without investigating precipitating factors—90% of cases have identifiable triggers 2, 5
• Do not overlook medication review—polypharmacy in elderly patients is a common precipitant 1, 2

Monitoring and Expected Course

• Monitor mental status frequently with Glasgow Coma Scale 1
• If condition worsens to Grade 3-4 HE (Glasgow Coma Scale <8), transfer to ICU 1
• Goal is improved mental status with 2-3 soft stools per day once ileus resolves 1, 5
• Monitor electrolytes closely to prevent dehydration and hypernatremia from lactulose 1
• Consider rifaximin as add-on therapy, though role in acute setting remains unclear 1