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Difficulty: EasyGastroenterology and Hepatology

An inpatient medical team is evaluating a 62-year-old man with a known history of decompensated alcohol-associated cirrhosis who developed worsening confusion and lethargy over the past 24 hours. He has a past medical history of chronic obstructive pulmonary disease. His wife, who is his legally appointed healthcare proxy, is at the bedside; his estranged son is also present and frequently interrupts the care team to demand interventions. Vital signs are within normal limits. Physical examination reveals scleral icterus, a moderately distended abdomen with shifting dullness, and a coarse, flapping tremor of the hands when the wrists are extended. Laboratory evaluation demonstrates an elevated serum ammonia level, a normal thyroid-stimulating hormone level with a slightly decreased free T4, and a urinalysis showing >105>10^5 colony-forming units/mL of Escherichia coli without leukocyte esterase or nitrites. The patient denies dysuria or urinary frequency. An arterial blood gas reveals a normal partial pressure of carbon dioxide. The son demands that the team immediately insert a feeding tube to provide nutrition. Which of the following is the most appropriate next step in the management of this patient?

  1. A
    Administration of intravenous ciprofloxacin
  2. B
    Initiation of non-invasive positive pressure ventilation
  3. C
    Initiation of levothyroxine supplementation
  4. Administration of oral or rectal lactuloseAnswer
  5. E
    Placement of a percutaneous endoscopic gastrostomy tube

Answer

Administration of oral or rectal lactulose
The correct answer addresses the patient's primary acute issue: hepatic encephalopathy. The patient exhibits classic clinical signs, including altered mental status and asterixis, in the setting of decompensated cirrhosis. The first-line treatment is lactulose. Lactulose lowers the colonic pH, which facilitates the conversion of absorbable ammonia (NH3NH_3) into nonabsorbable ammonium (NH4+NH_4^+). This traps the toxin in the gut lumen, allowing it to be excreted, thereby rapidly improving the patient's neurological status.

Step-by-Step Solution

1
Analyze the patient's core clinical presentation and physical exam findings.
The patient has known cirrhosis and presents with new-onset lethargy, confusion, and asterixis (flapping tremor).
Identifying the primary syndrome is necessary to determine the appropriate targeted therapy.
2
Correlate clinical findings with laboratory data.
Elevated serum ammonia confirms the clinical suspicion of hepatic encephalopathy.
Ammonia accumulates in advanced liver disease due to impaired hepatic clearance, crossing the blood-brain barrier and causing neurotoxicity.
3
Determine the first-line pharmacological treatment for the diagnosed condition.
Lactulose is selected as the optimal initial therapy.
Lactulose is a nonabsorbable disaccharide that lowers colonic pH, converting ammonia to nonabsorbable ammonium and promoting its excretion in feces.

Key Concept

Diagnosis and acute management of hepatic encephalopathy.
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Topics

Gastroenterology and Hepatology

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