It's not like this is the first time Kyle had trouble breathing in space. Sinestro snatch his ring from him in space. And he survived from it.
I'm expecting him to survive, because there's no way a known character's death would look so petty if you know what I mean.
And it makes no sense to have a potential GL limited series starring Kyle/Kilowog if he's dead.
So you have nothing to worry about.