My mother has “suddenly” become almost totally non talkative?

This relates to my mother, an 89 year old lady in the UK. Confined to a wheelchair for many years (ostensibly multiple sclerosis but questionable), and having a urostomy stoma, 5 years ago she went into septic shock following UTI which, though she survived and recovered brought out/forward vascular dementia.

The progression of her dementia has been slow enough to be imperceptible except in retrospect. 2 weeks ago I became aware that she had “suddenly” become almost totally non talkative, and what few words of intelligible English she had till now retained had almost disappeared. I feared and suspect this was a step change progression in her dementia. A hesitant and shaky use of her arms/hands when eating also became apparent. The possibility she may have another UTI as an alternative explanation did occur to me and her talkative interaction did appear to gradually improve over the following week. However last Thursday the urine in her night drainage bag was full of material and blood red..this quickly cleared but the following day mucous or pus was in her urine. Both consistent with a UTI.

District nurses took her readings and found her blood pressure was normal but her temperature was undetectably low so called out the doctor. He found the same readings and noting her cloudy urostomy bag had her admitted to hospital on suspicion of Urosepsis on the Friday evening.

She was given intravenous antibiotics and fluids for a few days, and seemed generally “normal” during most of her stay (though I noted each day her forehead still felt cool to the touch). By Wednesday we were told all her readings were fine and they were sending her home..though she appeared to me to be more ill than she had been to that point. She came home on Thursday (48 hours ago) with a course of oral amoxycillin. Her use of her arms remains painfully poor and is basically being spoon fed. Friday morning I noticed a large swelling and bruising on the shin of her left leg – not having seen her leg for over a week there was no way to determine if it was like this in hospital or had been banged in teh ambulance…or was a symptom of infection or disease. The doctor was called out and confirmed it was a bruise, not a thrombosis or clot. (It doesn’t appear to cause her any pain and is not warm to the touch) Later that day nurses again took her temperature during a routine visit and found it was still unnaturally low.
By this point I had read online that slow, uncoordinated arm movements and weakness can be a symptom of hypothermia itself (I left the heating on over night and she felt normal this morning though seems to be cooling again) I’ve also now read that unexplained bruising can be a symptom of sepsis. So I’m naturally very confused that all these things may or may not be connected, or has she simply deteriorated?

For the last 24 hours she’s mostly slept. When woken last evening she spent over an hour repeating meaningless words (“oh come on” ) over and over. Progressing dementia …or delirium? This morning and again this afternoon she’s only taken a few bites of food before refusing any more then going back to sleep. Her outward breath is very audible. When she does wake or eat she chokes or coughs a lot…again all this is new, but I understand consistent with advanced dementia…yet as I say I can’t help wondering especially given the temperature issue and possibly the bruising, if she does in fact have sepsis after all despite the hospital tests which deemed her fit for discharge.

The medical details on her hospital discharge notes read as follows
For “MSU Microscopy” it reads WBCs : <20 x10^6/L RBCs : Not raised x10^6/L Epithelial cells: Scanty Comment: Culture - No Significant Bacterial Growth For Blood Culture it reads"Culture negative after 72 hours incubation. A further report will only be issued on culture of a significant organism" Under Clinical course at the bottom of the page it says "Treated as urosepsis. Normal wcc . No urine investigations suggesting UTI. CXR - poor inspiration no real evidence of pneumonia. So is all of this the consequence of a progression in her mental decline? Or are the changes in her more likely to be the cause of still present sepsis, pneumonia , or some other condition? Without any new symptoms and her blood pressure, heart etc consistently reading fine, there's not an awful lot to take back to the GP. But something is clearly not right.