Hi, former air medical telecommunicator here..... We originally dispatched for 4 helicopters (up from 2 back in the day), and when I left, I think we had something like 10, just covering NJ. We never turned down a request (except when it was unsafe to fly, IE, weather), and it was always whomever was closest (with a little bit of politics thrown in), but helicopter transports are big money. That was why lawsuits were initially filed to open up the medevac system to private entities (and boy did it open up)
http://www.nj.com/south/index.ssf/2016/07/southstars_grounding_means_no_more_free_air_medica_1.html
http://www.nj.com/burlington/index.ssf/2016/10/legislators_call_for_south_jersey.html
back to the topic at hand....
So all you guys, who rarely have a nice thing to say about any dispatchers, are going to let them decide whether you, the person in the field, needs a helicopter?
or even better, your going to trust a "experienced air ambulance paramedic" who now works full time in control, and hasn't seen a real patient in 10 years, and allow them to overrule your clinical judgement?
In the litigious US, assuming the ground paramedic calls for the helicopter (and rightfully so), but the dispatcher doesn't feel the patient warrants it (because the paramedic didn't paint a good enough picture), and the patient dies as a result...... who should pay the punitive damages?
Honestly, it makes more sense to have the medevac approved by an field supervisor, medical director, or someone in the EMS agency's administration, if you can't trust your paramedics to call for the HEMS appropriately. Or if HEMS are being called inappropriately, than the agency should be responsible for QA, and for providing appropriate guidelines for when a helicopter should and should not be used.
If you joe public can't trust you to call for additional resources appropriately, why should they trust you to treat the patient?