Final answer:
In patients with cirrhosis, upper GI bleeding can lead to hepatic encephalopathy due to portal hypertension and the bypassing of the liver's detoxification system.
Step-by-step explanation:
In patients with cirrhosis, upper gastrointestinal (GI) bleeding can precipitate hepatic encephalopathy. This occurs due to the presence of portal hypertension, a complication of cirrhosis, which obstructs the passage of blood through the liver. When GI bleeding occurs, the blood bypasses the liver and toxic substances accumulate in the blood, leading to impaired brain function.
For example, if a patient with cirrhosis experiences bleeding from an ulcer in the stomach or esophagus, the blood will bypass the liver and flow directly to the heart without undergoing detoxification by the liver. This can lead to an accumulation of toxic substances in the blood, including ammonia, which can cross the blood-brain barrier and cause hepatic encephalopathy.
In summary, in patients with cirrhosis, upper GI bleeding can precipitate hepatic encephalopathy due to the presence of portal hypertension and the bypassing of the liver's detoxification system.