Over 17 months in to being a Paramedic, and I've had my fair share of critical calls... a full blown anaphalyxis, a profoundly bradycardic patient, anyone I've had to RSI, even an MCI MVC with fatality, stuff like that, and I've come to one conclusion:
I've been able to do what's needed to be done every time so far without delay.
I'm not saying I was always confident in my abilities, that I always knew what to do, but if there's one thing that I can pass on to new Paramedics or students is this:
You will do what needs to be done. If nothing else, your mind with resort back to 'cruise control mode' and do it itself. You just have to have composure about yourself and you'll do fine.