How London Ambulance is preparing for winter pressures

All accident and emergency departments experience peaks and troughs in pressure, often associated with the number of arrivals by ambulance.

This can mean unnecessarily long waits for patients to be treated, with the possibility that they will breach the four hour target for treatment, admission or discharge, and increased pressure on staff.

It can also mean hospitals face sudden demands for large numbers of beds for admitted patients. 

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New take on an old idea

Last year London Ambulance Service and its commissioners proposed a solution that would redirect ambulances away from the most hard pressed departments to ones that were less busy.

It worked with commissioners, including NHS England (London), and local hospital trusts to implement this in time for the key winter months, using winter pressures money.

‘Intelligent conveyancing involves an agreed maximum number of ambulances per hour arriving at each emergency department’

The public and healthcare staff are already used to the idea that an ambulance may take patients to a more distant emergency department if it has better facilities for serious conditions, such as stroke or major trauma.

“Intelligent conveyancing” takes this one step further by avoiding departments that are known to be under pressure, with potential benefits for both the NHS and the patients.

Patients going to a specialist unit are excluded, along with patients receiving ongoing care from a particular hospital and those who might have an extended length of stay as a result of being taken to a distant hospital; for example, because their care package would be hard to restart.

Intelligent conveyancing involves an agreed maximum number of ambulances per hour arriving at each emergency department with any beyond this diverted to other local emergency departments that have not met their maximum and therefore have “spare” capacity.

Unique perspective

The London Ambulance Service was in a unique position to identify where the pressures were in the system and take action. It has experience of controlling large ambulance flow from the Olympic Games and events such as Notting Hill Carnival and the London Marathon.

The scheme was launched in November 2013 and is used from 8am to midnight seven days a week.

‘A “deep dive” was carried out to look at the effects on particular emergency departments’

Working with NHS England’s London region, providers and commissioners, the ambulance service gathered data to analyse what has happened at a London-wide level and at individual trusts.

This has involved comparing data from the same periods in 2012-13 before the scheme launched and 2013-14. A “deep dive” was carried out to look at the effects on particular emergency departments.

Changing one element in a complex system can make it hard to attribute cause and effect, so we are treating the outcomes from this trial period with caution.

Promising signs

However there are encouraging signs: from mid January to mid February 2014 there was a 27 second increase in the average time taken to get patients to A&E.

But the average waiting time for handover from ambulance to hospital staff reduced by 180 seconds. Overall, this meant patients were in the hands of hospital staff 2.5 minutes faster than under the old system.

This may seem a small improvement, but across a whole system this could be significant.

‘A saving of 2.5 minutes per hospital journey is considerable as it frees staff to reach other patients more quickly’

The London Ambulance Service made 840,000 emergency journeys in 2013. While not all of those will result in patients being taken to hospital, a saving of 2.5 minutes per hospital journey is considerable as it frees London Ambulance Service staff to reach other patients more quickly.

A key performance indicator of ambulances being cleared to leave within 15 minutes of arrival at hospital is also more likely to be met if A&E departments are not swamped by too many vehicles arriving at once.   

There was also evidence that emergency departments were coping better with the pressures they face.

Further research

While there were an increasing number of ambulances being redirected from pressurised emergency departments for most of 2013, the period between November 2013 and February 2014 – when intelligent conveyancing was in operation – saw a significant reduction.

But an increase in resuscitation related redirections in January and February requires further research to establish the reasons behind it.  

There was a drop in the number of waits of more than 60 minutes for ambulance handovers compared with the previous winter; however the figures were not comparable and it is difficult to attribute this directly to intelligent conveyance.

‘One trust saw 119 ambulances directed away from it during a four week period, but 15 directed towards it’

At an individual trust level, emergency departments could have ambulances diverted away from them at busy times and towards them when they were less busy.

For example, one trust in south London saw 119 ambulances directed away from it during a four week period, but 15 directed towards it.

One north London hospital had 13 ambulances directed to it against 135 away. This reduced its “take” by 122 over four weeks: around 4 per cent. Those directed away during this period went to nine different A&Es. 

Intelligent conveyancing is likely to be most effective when it has overview of all the ambulances arriving at an emergency department: this means it may work best in central London rather than on the outskirts where other ambulance services may be delivering patients in addition to London Ambulance Service.

Fine tuning

If intelligent conveyancing is commissioned for next winter we will have an opportunity to fine tune its operation in the light of our experience since last November.

More work is needed to establish if it has any impact on the length of stay of patients taken to more distant emergency departments and to look at the impact on emergency departments on the outskirts of the capital.

‘We would want to devise a more scientific way of calculating ‘maximum’ ambulance flow and ideally linking this to bed capacity’

There could be opportunities to improve how it operates; for example, how to handle “displaced” crews who are out of their normal areas.

We were keen not to undermine the autonomous judgement of our experienced paramedics in the way the scheme was set up. Thankfully they have seen the benefits to patient care of not being taken to very busy emergency departments if an alternative can be found.

We would want to devise a more scientific way of calculating “maximum” ambulance flow and ideally link this to bed capacity. We found variations in how hospital capacity data is currently recorded and shared, which makes it difficult to use it to guide real time decisions.

We would need to look at how we respond to seasonal activity. Although this winter was busy there were not the extreme demands of a flu epidemic, extreme bad weather or severe outbreaks of norovirus affecting capacity. We may need to consider how intelligent commissioning can respond to abnormal pressure.

Spreading the word

The principles of intelligent conveyancing could be coordinated with other parts of the urgent and emergency care system such as NHS 111. Using a similar approach with urgent care centres could smooth pressures and improve patient experience there.

‘In rural areas, a modified form could help balance demand across acute and community hospitals’

These could drive changes to intelligent conveyancing, which could then be put in place for the start of winter 2014-15.

On the basis of our experience so far, intelligent conveyancing could have a part to play in reducing peak pressure on A&E departments in urban areas where distance and travel time between emergency departments are relatively short.

Increased coordination with other ambulance services across boundaries may further enhance this and is something we are keen to explore.

In rural areas, a modified form could help balance demand across acute and community hospitals, with some cases potentially being managed at home or in an intermediate care bed rather than being taken to a hospital that is struggling to cope.  

Fenella Wrigley is deputy medical director and Mark Doherty is director of commissioning at London Ambulance Service Trust, and Richard McEwan is surge capacity manager, emergency preparedness, resilience and response team (London region) at NHS England