THE American television series ER gives us an adrenalin-pumping, glamorised look at the work of accident and emergency staff.

But one group of local doctors works in conditions closer to those depicted in MASH.

Mid Essex Doctors Immediate Care Scheme (MEDICS) volunteers cover 800 square miles of rural Essex in a bid to provide a qualified doctor to back up emergency services in life-threatening situations.

Theydon Bois doctor Phil Koczan is one of a team of ten highly trained volunteers on call 24 hours a day, seven days a week.

The 35-year-old father-of-two is a GP at a surgery in Chingford, but for the past ten years he has also devoted his valuable time free of charge to saving lives in emergency situations.

He was introduced to MEDICS as a third-year doctor while working in casualty at Broomfield Hospital in Chelmsford.

'I have always enjoyed handling trauma in the very early stages and I find the difficult initial assessment of the patient quite challenging and rewarding. Doing that on the roadside is even more challenging than in hospital.'

With more than half the deaths at accidents occurring within 15 minutes, medical aid is vital to stabilise a patient's condition.

Dr Koczan said: 'There is a period called the 'golden hour', which is the first hour after any injury and the more you can do in that space of time the better.

'Particularly with a trapped patient, it can often take over an hour to get them to hospital. Having a doctor on scene at an accident can make a lot of difference ? we can do more things than a paramedic and an extra pair of hands is often beneficial.'

MEDICS was set up 22 years ago by Saffron Walden GP Dr John Eaton as Saffron Walden Accident Group and comes under the umbrella of the British Association for Immediate Care (BASIC).

Dr Koczan is also a member of BASIC, and his colleague at Chingford's Churchill Medical Centre, Dr Rodney Herbert, has been a BASIC volunteer for over 25 years.

Based in Great Chesterford, MEDICS covers an area from there to Rayleigh in the south and from Danbury, near Chelmsford, in the east, with the M11 corridor forming the western boundary.

It overlaps with the similar BASIC service in London to provide blanket coverage in the local area.

Like the other doctors on the MEDICS team, Dr Koczan carries advanced medical and communication equipment to the scene of an accident. This equipment and any medication given at the scene is not supplied by the National Health Service and the costs ? tens of thousands of pounds to outfit each doctor ? have to be met by donations to MEDICS.

They also carry some advanced equipment not found in ambulances, including a vital body functions monitor and tools to drain fluid from the chests of accident victims.

But every time the beeper goes off, it could signal a completely new challenge.

Road accidents are the most common incidents MEDICS doctors are called to, but they have also attended stabbings, shootings, train and plane emergencies and explosions.

Dr Koczan was part of the emergency response team which attended the Bishopsgate and Canary Wharf bombings.

He agreed that the task was closer to the battlefield medicine depicted in MASH than the slick hospital drama ER.

'The big difference is that we haven't got all the extra equipment they've got in a hospital, we don't have all the diagnostic tests and we haven't got all of the people. So we're working with a very small, dedicated team in often very difficult situations people trapped in cars, for example, or people who are losing a lot of blood from a leg that you know will take the fire brigade half-an-hour to release.

'Chaotic is the wrong word, but it's not an environment you can control when you're on the motorway with cars speeding past, and it's throwing it down with rain, and you have all the normal hazards of being out on the open road.

'The big thing is when there is a difference, when you actually save a life. That can be a very rewarding experience.'

MEDICS spokesman Michael Patmore said the team would dearly love to expand the service to cover a wider area and include more doctors.

To do so, funds are desperately required to update existing equipment and expand.

The charity is looking for volunteers to run on its behalf in the Great North Run or next year's London Marathon.

Anyone with fundraising ideas, or who would like to make a donation, should ring 01799 531218.