Best of luck with the rest of your journey, they like and need to be prepared with problems like these, because if yu have the sleep apnoea and they are not aware of it it can be very dangerous, with anaesthetic, they said sometimes bringing you round could tak e alittle longer and there are obviously different signs for them to watch out for as you can apreciate anaesthetic is a very technical thing, they need to know and everything that may possibly be needed, also they are prepared case you need to go to intensive care unit. I didn't need that just came round penty of oxygen back to ward. Nevre used machine till night time as usual so just do what they say they no best. You will get used to your machine just takes bit time. Anything was better than my snoring and snorting waking myself and the family up every night haha xx Any questions just ask away xx