well, I'd call 911 not 999 if I had to do anything.. but to be honest, its totally on you.
have you been through this before? difficulties breathing how? just having a hard time catching your breathe? if you are that fucked up how did you find a way to even post on this board w/o any problems aside from that 911 thing!
the nod comes w/ pheni/fent combo, easily. you should expect that nod. have you combined these two before? did you know what to expect?
again, the 911 is totally ON YOU; if you do not feel safe, then call 911 and BE HONEST W/ THEM. DO NOT WASTE TIME AND SAY YOU DO NOT KNOW WHAT HAPPENED.