Up here in New Hampshire, that's a rather gray area [heh, it's EMS, what isn't?]. Typically, we do not use them for access unless it's an inter-facility transfer and the access whether it be PICC, CVC, etc., in which we can continue it. NH's protocols allow for -any- facility initiated treatment to be continues, except for blood products...but that may soon be changing. I have not heard of anyone carrying non-coring needles for indwelling central lines. Our medical control has mentioned if encountered with someone with already in place access, and peripheral access isn't obtainable, or difficult, and you kinda need access,to contact them for options.
The adult IO access is becoming much more popular up here, however.