I did have some weird feelings. I saw a kaleidoscope of colors at times. I also felt like I was in an airplane and like things were vibrating around me.
We learned that relaxing music actually doesn't help, faster music or commedy worked better for me both in terms of enjoyment and breathing. My oxygen saturations were better with those types of music.
My blood pressure behaved itself, though it was higher than I prefer. Overall, though, it's been safe, even though it's not easy.