By Nick Triggle
Health reporter, BBC News
Ambulance unions and some doctors fear plans for vehicles manned by one person to answer more 999 calls in England could put patients at risk.
More than 5m emergency calls are made each year
NHS bosses are splitting up many two-person ambulance crews in an effort to meet new response-time targets.
Some staff say "solo-responders" are not always appropriate and that it is a bid to get the service on the cheap.
But ministers insist the move "does not present a risk to patients" and that it will free up resources for other calls.
From next April, the 10 ambulance trusts in England will have to respond to three quarters of the most serious emergencies within eight minutes from the point the call is answered.
WHAT IS A SOLO-RESPONDER?
Solo-responders, or rapid response vehicles as they are sometimes known, are basically estate cars or 4x4s equipped with the resources of an ambulance
They became popular in the 1990s as ambulance bosses came under pressure to hit response-time targets
The vehicles are only manned by one person unlike ambulances which are double-manned. This poses issues if the person needs to be transported
There is no policy banning the transportation of patients in rapid response vehicles, but doctors and paramedics have concerns
To date, the clock has only started ticking once details, including telephone number, address and problem, had been taken.
Critics said this process had been taking several minutes in some cases, masking the true response times.
The BBC has learned that all but one of the ambulance trusts submitted plans to the government in the autumn putting forward the case for using solo-responders more.
And officials believe the remaining trust, which has not been named, will take such an approach later.
Ambulance bosses are now ordering new fleets of solo-response cars with a view to splitting up many of their double-manned ambulance crews to ensure they have enough resources to meet the target.
The ambulances left in operation are likely to be run by a paramedic working alongside an emergency care assistant, trained in basic life support and first aid.
Department of Health staffing projections show that the number of assistants is set to treble to over 3,300 by 2011.
The South Central Ambulance Trust has confirmed it will be responding to most emergency calls by a solo-responder in the future.
And in London, the capital's fleet of solo-responders will increase by 50% to 200 by April.
Meanwhile, East Midlands bosses are reducing its ambulance fleet and increasing its solo responders so that a third of its fleet is cars compared to a quarter currently.
Tony Dell, chairman of the NHS Confederation's ambulance forum, which represents trusts, said: "It is going to be beneficial to patients. They are not going to see any diminishing in skills and the responses will be faster."
But Jonathan Fox, of the Association of Professional Ambulance Personnel and the driver of a solo-responder vehicle, said: "We are trying to do things on the cheap and that is never good for patients.
"We are already hearing of solo-responders transporting patients, but that is not right as you cannot manage the patient if you are driving.
"Solo-responders have their place, but the emphasis now is on hitting the eight-minute target rather than what is happening once you are there."
Sam Oestreicher, of Unison, agreed the target distorted priorities and could "potentially put patients at risk".
"You may get solo-responders sent when an ambulance crew would be best."
But he also added the deployment of solo-responders was appropriate in some cases as the ambulance service was increasingly dealing with non-life threatening conditions.
Concerns have also been expressed by doctors. Martin Shalley, of the British Emergency Medicine Association, said: "There is a concern that because of the target solo-responders will be sent out when an ambulance crew should.
"Sometimes patients are so seriously hurt you need more than just one person there immediately."
But Health Minister Ben Bradshaw said the reliance on solo-responders "does not present a risk to patients" and freed up resources for other calls.
He added: "Fast-response vehicles can often get to the scene faster than traditional ambulances, and can provide assessment and care until a further response arrives."