Final answer:
The primary factor causing encephalopathy with cirrhosis is the elevated of ammonia levels in the blood due to the liver's inability to metabolize it.
Step-by-step explanation:
The primary factor causing encephalopathy with cirrhosis is the elevated ammonia levels in the blood. In liver failure, whether chronic or acute, the damaged liver cannot properly metabolize ammonia, leading to its accumulation in the bloodstream. This elevated ammonia then enters the brain and causes neurological dysfunction, resulting in encephalopathy.