USMLE® Step 1 style questions USMLE
A 54-year-old woman is brought to the emergency department by her partner due to altered mental status for the last 2 days. According to her husband, the patient has become increasingly lethargic, disoriented, and agitated. The patient has a history of chronic hepatitis C infection that was diagnosed 14 years ago. She refused all treatment at that time. Temperature is 37.0°C (98.6°F), pulse is 98/min, and blood pressure is 104/74 mmHg. On examination, the patient is lethargic and oriented only to self. When her hands are outstretched in front of her and extended at the wrist, they exhibit a flapping tremor. The abdomen is nontender and mildly distended; shifting dullness to percussion is present. There is no nuchal rigidity. Stool occult blood is positive. Laboratory testing reveals the following findings:
The patient is started on emergent therapy for her symptoms. Which of the following best explains the pathophysiology of this patient’s current condition?
Hepatic encephalopathy is a neurological disorder that results from liver failure. The leading cause of hepatic encephalopathy is a buildup of toxins in the blood that are normally removed by the liver. These toxins include ammonia and other chemicals produced by gut bacteria. When the liver fails, these toxins build up in the blood and can poison the brain. Hepatic encephalopathy can cause changes in behavior, confusion, problems with coordination, and seizures. In severe cases, it can lead to coma or death.