A few words about the AA approaches that I have come across.
Just yesterday I came across a project that is expected to bring more diagnostic capability to the flightsuit pocket of air ambulance medical staff.
One manager from a rural UK air ambulance district has been annoying some of his air ambulance colleagues from more populated areas by stating that the only valid reason for having an air ambulance is rural location and distance.
Norway has only six SAR helicopter bases but a network of 12 helicopter air ambulance bases (& 7 FW) with some enhanced capability and typically flying with pilot, doctor and paramedic (sometimes rescuer). The Doctor and Paramedic are trained to provide aircrewman services during different phases of the operations. One mode of operation is to insert a paramedic at the casualty's location, possibly using long-line, so that there is medical aid until the SAR helicopter arrives to extract with its winch. Getting help to the casualty's side in the minimum time seems to be given a very high priority and then extraction can take place when the appropriate resources are available.