Call selection for the Helicopter Emergency Medical Service: implications for ambulance control.

The increasing sophistication of pre-hospital care, with paramedics and many types of 'rapid response' units, requires the use of advanced systems of ambulance control. The introduction of call selection by a paramedic in the ambulance control room significantly improved the tasking of the Helicopter Emergency Medical Service. This paper illustrates the need for a system to grade 999 calls, so that the appropriate pre-hospital response can be directed to each patient.