A young woman collapses in London's bustling Oxford Street. An undetected cardiac condition has caused her to fall victim to a massive heart attack. Bystanders rush to help, but she shows no signs of life.
As little as five years ago, our heart attack victim would have been declared dead on arrival at hospital. Today, against all the odds, she has a fighting chance – thanks to a revolution that has taken place in trauma and emergency care in the UK.
The reasons for this unsung miracle are explored in An Hour to Save Your Life, the new OU/BBC three-part documentary series which follows nine life-or-death emergencies as they unfold – from first response, to the work of highly-skilled medical teams in specialist trauma centres which now cover most of the country.
It's the first time that frontline emergency care has been seen in such detail on British television.
An Hour to Save Your Life contains procedures never filmed before, and will be used as a resource in the OU's foundation degree in Paramedic Sciences – a programme which is currently training one-quarter of the UK's student paramedics.
An Hour to Save Your Life highlights how if you suffer a traumatic injury, a heart attack or a severe stroke, your chances of surviving and making a good recovery are markedly better than they were compared to only a few years ago.
New equipment, new drugs and new techniques are all playing a part, but an underlying factor is a greater focus on bringing together all the scientific knowledge that exists about trauma and putting it into practice.
"We have seen a move from opinion-based practice to evidence-based practice," explains Dr Hilary MacQueen, OU Senior Lecturer in Health Sciences, and academic consultant to the series. Ironically, a leading factor in saving lives has been war, she says.
"There has been a lot of learning from the battlefields of Iraq and Afghanistan which in turn has driven developments such as new emergency dressings to stem bleeding, different ways of saving injured limbs, and a better understanding of the time-critical nature of some injuries."
The knowledge gained on the battlefield has fed into NHS hospital practice and the training and equipment given to the front-line of trauma treatment, the paramedics.
"Even five years ago, paramedics could have had as little as six weeks' training," says Dr Duncan Banks, Lecturer in Biomedical Science at the OU, also academic consultant to An Hour to Save Your Life.
"Now it takes four years to qualify with the OU, the equivalent of two years full-time. Paramedics are so highly skilled that some are working in hospital Accident & Emergency departments."
Today's paramedics are equipped with new drugs to stop bleeding – now identified as a top priority in most trauma cases – new stretchers which minimise the amount a casualty has to be moved, and new devices like the autopulse which carries out chest compressions on heart attack victims automatically, leaving the paramedic free to perform other treatments.
Paramedics at the scene can also call on a range of more specialised emergency support vehicles, which may include air ambulances with blood transfusion facilities and, in many parts of the country, 'cool cars'.
These 'cool cars' carry equipment to reduce the casualty's core body temperature, delaying cell death and limiting permanent brain damage in cases of heart attack, stroke and head injury. This kind of 'therapeutic hypothermia' was used to treat racing driver Michael Schumacher at the scene of his recent skiing accident.
Once at hospital, new trauma procedures put emphasis on delivering patients very quickly to one of today's highly sophisticated CT scanners (which can be pre-booked by paramedics at the scene of the incident) and/or the operating theatre, where they benefit from the advances that have been made in trauma surgery.
One of the many 'firsts' for An Hour to Save Your Life is the filming of a trauma team using the life-saving REBOA, a relatively simple device which keeps blood flowing to the brain and heart while surgeons are working out how to repair an injury.
Keeping up-to-date with all these developments is part of the job for academics like Duncan and Hilary who are involved in the OU's health sciences and paramedic sciences courses.
That's why they have been so enthusiastic about working on a BBC documentary that has provided privileged access to state-of-the-art trauma care.
"An Hour to Save Your Life is a unique resource," says Duncan. "It looks at just the sort of scenarios we teach our students.
"We can use a lot of the material, including material that doesn't get broadcast, in our OU modules and assessment."
An Hour to Save Your Life also makes for gripping television, as we follow the race against time to save patients such as the young Oxford Street heart attack victim.
But it comes with a bit of a health warning for viewers, as Hilary explains: "Be prepared for an emotional rollercoaster. We are dealing with real life-or-death situations and sometimes, that can mean death. There is not always going to be a happy ending."
An Hour to Save Your life is first broadcast on BBC Two on Tuesday 4th March at 9pm. There's more information about some of the medical science involved in a free OU booklet called Trauma and Emergency Care which accompanies the series.
There's more on the series on OpenLearn's An Hour To Save Your Life section.