Husband with dementia had pneumonia and sepsis, ended up in the hospital, and now his dementia is worse! Will it improve?

Any interruption in routine can exacerbate dementia especially a stay in the hospital. In a hospital there is no day, no night, no time frame and strange faces coming and going. It's very difficult on a person.

It's impossible to say if your husband will bounce back or not. That's probably a question for his doctor.

Good luck with getting any answers from doctors - they really don't have any clue either. Everyone is so different and what their other medical conditions are - so many things impact people differently but I hate to say that once the decline begins it's rare if not impossible to see improvements. So in my opinion it is best not to expect it and if it does improve feel blessed but anticipate the worst and you won't have such a hard time coping with something you didn't see coming. We all prefer denial but reality is harsh and swift.

Pneumonia used to be called the "old people's friend," as it caused a relatively peaceful death before the person lived on to develop lots of worse conditions--dementia being among them, in my opinion. My great grandmother had dementia in pre-Medicare/Medicaid times. She lived with my grandparents who never took her to a doctor (although I don't know if she had any conditions that would require medical care these days). When she quit eating, they didn't try to feed her and so she died. It sounds cruel, but she didn't drain time and money from my grandparents (who were busy during day with their flower shop) and my mom, who took care of her during the day. My family lived with my grandparents as well, they had big old house. If I develop dementia, my kids are under strict instructions not to call the MD to treat any life-threatening illness--pneumonia, heart attack, cancer--but to let me die. Why our society values life over quality of life is beyond me!

As posted before, doctors can’t be much help. It’s a ‘wait and see’ situation - people are different and react/respond/recuperate differently. I have cared for my father with Lewy body dementia (at home for 14 years and going on two years in a facility) and have witnessed these changes; general anesthesia is an enemy to someone with dementia and it takes them much longer to regroup. My father has bounced back some after a total hip replacement, the move from home to memory care, and even changes to his medicine. But dementia is a progressive disease, and decline is inevitable - that’s our ‘normal’ now, unfortunately. I am sorry to say that you are in for a lot of ‘firsts’. I rejoice on the days that he knows who I am! My only regret is that I did not find this site sooner to help me through those first dozen years - you have many friends here that have experienced multitudes of situations and will be happy to share their experiences with you to help you in any way they can. My thoughts, prayers, and hugs are with you and your family as you go through this journey.

Great answers/advice given.  Based on my own experiences;  it may improve - or maybe it won't - time will tell.  When my Dad was hospitalized with the flu, it changed his life.  He regained his cognition for the most part, but he hasn't driven or walked without a walker, since.  My Mother had a traumatic event that landed her in the hospital and I thought she would never be the same.  Not so.  I am thankful to say that about two weeks later, she was back to herself.  (She has advance dementia).  I pray that things improve for you and your husband - One day at a time ....

Yes having pneumonia compromises the oxygenation of the blood, thus less “fresh” blood to Major organs like the brain. It will take some time to get back to his baseline or where he was prior to his hospitalization.

I’d be more concerned about what his sepsis status is.
Did his physicians at all mention “MODS” or his going into “cascading” of care needs? Sepsis is pretty serious to deal with even if you were previously healthy and get really bad pneumonia and then get something else - like a bad infection - elsewhere and get septic.
I’d suggest you contact his MD to see if any of the changes are symptoms of his going into MODS phase. My MIL was septic & went into MODS. She went into a free standing hospice facility post hospitalization rather than going back to her NH; and it was covered by Medicare. imo MODS needs a care team and beyond what a spouse on their own can do at home or a NH can do.
Please call his MD to discuss what’s happening.

Everyone is different but I doubt there will be much improvement. Once my mom was hospitalized for pneumonia she had full blown dementia come on immediately. She has only declined since and rapidly. She had been driving, living independently and managing her own finances till then, once hospitalized she couldn't done any of that on her own. She had to be hospitalized again a couple of months later to have a breast removed and it worsened again. Now she is in an assisted living facility and she still knows most of her family but not much else and it gets worse day by day.

Read up on something called “ICU delirium.” That’s what happened to my mom; it’s taken about a year for her to come out of it.

He will probably not get back to the point he was prior to the illness. And with each illness or hospitalization he will not recover to the "starting" point.
He will improve. It may take weeks or months depending on how severe the illness was and how long he was in the hospital.
Side note this is a problem with ostomy's, feeding tubes and IV's people with dementia will pull them out. "they just don't belong" to their body and they do not understand that it is something that may be needed. (I will not get in to feeding tubes or other procedures that may not be wise)
Keep things as "normal" as possible, get him back on whatever schedule he was on before. If you have him in Day Care get him back as soon as possible. A routine is important and the sooner he can get back on track the better.

If this was a pneumonia caused by aspiration this may happen again. If it does happen again you might want to discuss with the doctor about thickening liquids so it will be easier for him. At some point the body/brain does not recognize liquids and will not close off the way to the lungs. This will lead to more bouts of aspiration.