My husband has stage 4 cirrhosis. What can I do to help improve his quality of life?

See below. Make sure he follows up with his doctor properly, takes his medications as prescribed, maintains a low sodium diet and avoids alcohol.
Be supportive. Depends on what kind of cirrhosis. If it is viral, treatment with antiviral agents can help preserve what liver function exists and even allow some healing. Avoidance of any alcohol is absolutely critical, as well as any regular use of other hepatotoxic drugs. Like nsaids and tylenol (acetaminophen). Consideration of liver transplantation, and other specific remedies is important, as is diet/exercise.