Location, location, location!
The criteria we apply in Devon go beyond the straightforward life or death 999 calls because of the unique character of the county. We have two long and rugged coastlines, two wild and remote moors and more narrow country lanes through rolling countryside than you can shake a stick at.
More often than not, if we are attending to a minor injury it is because the patient is in a remote area or inaccessible by road. In these circumstances, what starts as a minor injury can easily lead to a more serious situation. A good example of this is an elderly person with a badly sprained ankle on Dartmoor. A long wait in the cold for a rescue party to stretcher them off the moor could lead to complications like hypothermia and shock.
Additionally, some relatively minor injuries like a broken ankle, if not treated quickly, can lead to permanent disability and even loss of limb.
Finally, physically stretchering someone off the moor or across farmland places both patient and rescuers at further risk.
Poor information
Sometimes the 999 message can make it sound as though the injury could be more serious than it turns out to be. Callers are frequently confused, distressed and unable to give a clear description of the patient's condition or even whereabouts. One of our HEMSdesk despatchers told me of one caller who insisted he was on the A30 at Ashburton (an impossibility for non-local browsers!). In either case, it is better to be safe than sorry as any delay could be life-threatening.
Another frequent situation is that there are a number of 999 calls made about a single incident because more people have mobile phones and will report an accident, perhaps on the other side of a dual carriageway. They aren't able to confirm details but might report a car has rolled over or a motorcyclist collided with a lorry. Again, people can and do walk away from incidents like this but our crews are not going to sit around waiting for someone to confirm whether they are or are not needed when crucial minutes might be wasted if they are.
To sum up, we'd much rather be on our way and then stood down than not go until we are called in by a land crew by which time much of the speed advantage of the aircraft is lost. The introduction of specially trained despatchers has significantly reduced the number of aborted missions over the last year but we would be very concerned if there were none.
