Can you explain that a bit more? How does it work, and how well is it working? I've read about a couple of Canadian services that will refuse transports if they don't meet their criteria, so just curious.
As an aside, I've worked alongside (not for) 3 different flight services. None asked for the resosn for a field responce, just the weight of the patient.
We have basically 2 tiers of triage between the event and the helicopter. I sit in the dispatch centre, screening jobs (not just flight jobs) after they have gone through ProQA and liasing with the medical, pediatric and neonatal retrieval teams and hospitals, as well as providing medical advice to the crews in the field.
We then also have a flight coordinator. Their normal day to day business is primarily based around scheduling of routine flights (we have fixed wing who essentially do flying non-emergency transport due to the distances that have to be covered) and flights that the medical retrieval teams need to do (mostly fixed wing, some rotary). They also talk to me when I want a helicopter, or when they need a crew to pick up a patient and take them to the airfield.
So, a job may come in via the call-taker that is an automatic notification for HEMS, such as entrapment or major burns. This does not necessarily mean that HEMS will launch, merely that they are made aware so they can let me know what helicopters they have available. Depending on the details I have on the screen (or what I can get when I call the scene back) and the availability of road resources, I may ask for the helo to be launched (eg if the calls coming in sound terrible, or if there are access issues like needing a winch or if road is a long way away)
During my normal role of screening calls I may also identify other jobs that are not automatic notifications and ask for them to be sent to HEMS as well.
Normally however the crew will arrive first and then request a helicopter. In order for me to send that request to HEMS they have to essentially convince me that there is a genuine clinical need for the advanced skills the flight medic brings (our flight medics carry blood and other exciting stuff) or that transport by road would be detrimental to the patient.
If they don't give me a good story, or I decide that they are best served going direct to the closest hospital and arranging secondary retrieval or whatever, they don't get the helicopter. They don't like it, but that is just too bad.
If I think that the reason they want a bird is sound, I pass it on to the flight coordinator and they task whichever resource is most appropriate. It used to be (and still is to some extent) that the flight medic can still say no at this stage. They generally trust our judgement though. However, the pilot can say no at any stage, even after the helicopter has launched, if they deem it to not be safe. The pilot's word is law.
It can be very frustrating as we rely heavily on the word of the crew on the ground. Most are very good, some like to see the whirlybird land so they make the job sound a whole lot worse than it is, and others just can't even get around to giving a sitrep, but then get all angry when I say no to them.
We do want to support the staff on the ground with whatever resources they need, but helicopters, and the highly experienced and highly trained people that staff them, are just too precious a resource to be squandering on trivial jobs.
For the most part it works well. It is always a juggling act: sometimes a bird goes to a job where they aren't really required, and some jobs that could benefit don't get one. Mostly though we match up the need with the resources pretty well, so the sickest patients get the highest level of care in the shortest time possible. And most importantly there are no heroics and no helicopters crashing.
