Sue, I was diagnosed with really sever apnea about the same time I was diagnosed with my friend Bob. I had been on Bi-Pap for a month prior to surgery and had my first follow-up appointment the day before surgery. The various docs had encouraged me to have my mask and machine ready to be brought in by my wife. One of the sleep technicians even cut a section of the head gear out so it would minimize impact on surgery site.
Unfortunately, in my case it was all for nothing. I ended up being intubated for six days and because of the trauma to my nerves, my salivary glands did not all function (still do not) so for several months after I still could not use the machine because of severe dry mouth. But, they did take my machine, certify that it met standards, put a sticker on it, and we did try using it. It ended up just being easier leaving me on O2 for awhile.
In any event, make sure you have copies of your sleep study and diagnosis and give them to your surgical lead and whoever is acting as your patient advocate. The medical team wants you to have the best care possible and in order to do that, they need to know what your needs are.
Don't be distressed by how things went for me I simply had a different experience than most and all is working out just fine.
Tod