I don't think you'll find nation-wide companies, but if you call your local airport, they can probably tell you if there are charter airlines that could meet your needs. The other thing might be to talk with your local hospital. If they don't know, they might know where to call to start your search. Here's one place you might start:
https://www.angelmedflight.com/air-ambulance/?k...(Phone number can only be seen by the question and answer creators)&st-t=ppc&vt-k=air%20ambulance%20network&vt-p(Phone number can only be seen by the question and answer creators)&vt-p2[[phone:]]&_st_custom_value=kwd-(Phone number can only be seen by the question and answer creators)&utm_term=air%20ambulance%20network&utm_content(Phone number can only be seen by the question and answer creators)&adgroup(Phone number can only be seen by the question and answer creators)&targetid=kwd-(Phone number can only be seen by the question and answer creators)&device=c&matchtype=b&extension=&gclid=CjwKCAjwiN_mBRBBEiwA9N-e_rtK02ziF-6v4hpQiK09VXqTHzpVG-QzDix4fg14h6qO_xfSGh7NzBoClpQQAvD_BwE