capping

I have a question & need to ask the experts........we are allowed to try to cap Luke & he absolutely HATES it. We are getting a bronch at the end of the month. (the only one other then when they decided to trach him.....almost a year ago). He can wear PMV with no problems, even takes naps with it. No desaturations, no signs of distress, NOTHING. The thing is, he was trached for secretion control, NOT breathing problems, so what's the problem? I'm not sure how strong our Dr is on the capping step. As I've mentioned before, we're not thrilled with him anyway & are in the midst of finding a 2nd opinion. Any suggestions on him tolerating it better? He won't even last a minute before he starts stressing out & his lips turning blue......I just don't understand.

Thanks,

Kristi