Honestly tho your lungs could heal more than anyone expects. I'm not pandering, i was ventilated a long time ago like 1998 i think, (and what landed me there was also a threat to my lungs so i was given this warning multiple times). It has never affected anything i can notice. My lungs were weak for a few years and i haven't felt it since (granted i don't smoke). Its a doctors disclaimer (whether you were ventilated or not but especially if you were, it is their standard disclaimer.. kinda like people at retail stores have to tell you to have a good day. I was told that then cuz i asked and Ive been told that by multiple people at the time of treatment since then).