@sharonagnes, I want to welcome you (and your husband) to Mayo Connect. I know from what my own dear husband experienced as my liver/kidney transplant caregiver that your role caregiver is a difficult one.
Hepatic Encephalopathy is a buildup of toxins in the brain.. A liver damaged by cirrhosis isn't able to clear toxins from the blood as well as a healthy liver can. These toxins can then build up in the brain and cause mental confusion and difficulty concentrating. With time, hepatic encephalopathy can progress to unresponsiveness or coma. As a patient with liver disease, I was alerted early in my treatment to be aware of HE, and at each appointment my husband was asked about any signs of HE.

I am happy to see that @athenalee has already shared information that I hope that you will read.

I want to invite @kltchrmn, @contentandwell, @jodeej, @gaylea1 to this discussion and to share an update about their experiences with HE, Lactulose, and post transplant life.

I have located some information about experiences with HE and lactulkose on the first 3 pgs of the transplant Discussion > Liver pre-transplant question https://connect.mayoclinic.org/discussion/liver-pre-transplant-question/

@sharonagnes, How often does your husband see his doctor? What are they saying to you about his moods and a possible medication adjustment?