Here is a list of air ambulance aircrafts used to transfer patients:

Short Range

Cabin class twin

180-250 MPH

Cessna 340,414: Aerostar

Usually used for 200-1000 mile distances

Medium Range

Turbo Prop Jet

250-330 MPH

King Air 90,200, MU2

Usually used for 200-2200 mile distances

Long Range

Jet Propelled Aircraft

400-500 MPH

Learjet 25,35,36,55;Westwind;Citation IV,V;Diamondjet

Usually used for 400-3500 mile distances

Long Range VIP

Jet Propelled Private Aircraft with VIP Setup and Interior

400-500 MPH

Gulfstream IV,V; Boeing 757; Boeing Business Jet

Usually used for 400-7700 mile distances