End stage COPD-need some advice

Hello

I am the primary care giver for my husband who has end stage COPD, heart failure, atrial fibrillation, and chronic kidney failure. His prognosis is not good and I currently provide palliative care for him at home.

I take his observations a few times a day. His pulse is normally high varying from 98-115 of which he takes medication to reduce this. His blood pressure is normal at 121/82. His oxygen levels are normally 91-93, but after doing his obs this morning it has risen to 99.

I thought this may be a false reading, so I did it on another finger and got the same reading again. I then waited 20 minutes before doing it again but got the same reading of 99.

I'm concerned that this could be a sign of toxicity or hypercapnia caused by carbon dioxide retention.

Please could you give me some advice