Having advanced teams is no damn good if you’re not doing your best to get them to the patient where they might add value. Dr Alan Garner returns with reflections on recent publications on this coming out of Europe. It’s a bit of a passion of his.
Advanced capability prehospital medical teams may well be great, but they are an expensive resource that needs to be matched to the patients that are most likely to benefit. But these patients represent a very small percentage of the total numbers of calls to ambulance services so a way of accurately filtering the calls is critical to optimising the utilisation of such teams.
This of course means an accurate case identification system is required to dispatch these teams to the right patients, and preferably only the right patients. This is a kind of ‘Where’s (severely injured) Wally?’, all day, every day. It is really hard to pick which of the red striped shirts is blood and the signal to noise ratio about the same as a Where’s Wally picture. In NSW only about one in every 250 calls to Ambulance is a severely injured patient.
When it comes to dispatch of advanced capability medical teams (rather than which patient should go direct to a trauma centre – the two things are not necessarily the same) there is not a huge amount of literature out there yet. This has been identified as a priority research area for HEMS.
Hence I was really interested in a new paper just published by the people from EMRS Scotland on case identification in severe trauma. Those who follow The Collective will be aware of my interest in this area from the work we have done in dispatch in NSW that arose as a spin off from the Head Injury Retrieval Trial, particularly in children. You can find an earlier post on this here.
What the Scots did was move one of their clinicians who work on the service, either a paramedic or retrieval practitioner, into the control centre to look for cases that might benefit from an advance medical team response. Prior to this move the case identification was done by non-clinical dispatchers with some oversight from paramedics and nurses who were not involved in provision of the Scottish retrieval service. They used a simple before and after methodology to see how many of the severe trauma cases that occurred in Scotland were identified by the new system including the EMRS clinician versus the old system with the control room staff only.
The result was an improvement in sensitivity for major trauma that increased from 11.3% to 25.9%. Although 25.9% does not sound great it is possible that the new system identified almost all the severe trauma that was in the areas that the EMRS responds to. EMRS are not dispatched to urban areas in close proximity to major hospitals but injuries occurring in these areas were not excluded from the analysis. Since Scotland has a predominantly urban population it is very likely that most trauma occurs in urban areas (like it does in NSW) so if they are identifying a quarter of all the severe trauma cases this may represent almost all the severe trauma that is in their response area. Unfortunately this is not examined in the paper (I mean you can’t always cover everything) and more studies will be needed to clarify this.
Regardless of this methodological issue they more than doubled their case identification rate by putting a member of the EMRS team in control of identifying the cases. Such systems are common in the UK. As far as I am aware the first to publish this were London HEMS in early 90s where they were able to demonstrate a really dramatic improvement in sensitivity when they put one of the flight paramedics into the central control room. So this is not a new bit of learning. It’s reinforcing what we should know.
Stories we have heard before…
When we started the Head Injury Retrieval trial 13 years ago we had something like the London system in mind. By accident we stumbled upon an improvement though. Between 1989 when London HEMS set up their system and 2004 when we were planning the trial the internet had arrived. We were able to build a system where the crew at the helicopter base was able to screen the calls and identify the cases directly from the Ambulance computer system rather than putting a flight paramedic into the control centre.
This contributed to the trial HEMS system being the fastest reported to date in the world medical literature. We could get airborne about 3 minutes faster than the reports out of London and we’re pretty confident this was related to the ability to do multiple things simultaneously because it was all happening on base. At the same time as a clinically involved crew member was looking at the details of the case, aviators could start identifying potential landing sites and making plans. The pilot could head to the helo and start the checks even as that was happening. An experienced crew of 4 looking at cases also allows plenty of bouncing things off each other. There’s just a bunch of seemingly little stuff you can start working on that adds up to a significant bit of time-saving.
The trial system was however shut down at the end of the trial in 2011, and dispatch in NSW is now done by control room staff who are not involved in service provision.
It is worth noting that the system used to identify severely injured children when HIRT was recruiting was associated with zero safety incidents of even a minor nature, no unintended dual responses by physician teams and zero cost. But it doubled the rate of identification of severely injured children for physician team response and decreased time to a paediatric trauma centre by half an hour.
It is now seven years since this case identification system was discontinued by the powers that be and there is still no suggestion that it will be recommenced. This is despite the mounting evidence of system deterioration and concerns about inevitable missed cases and delayed responses resulting in poor clinical outcomes.
It is notable that other services are now commencing the direct screening by HEMS crew case identification system. Have a look at this article on the Great North Air Ambulance in the north of England. It sounds like exactly the process we used during the Head Injury Trial to identify severely injured children in Sydney more than a decade ago.
This comment from Andy Mawson, Operations Manager for Great North Air Ambulance is central to the whole thing:
“It’s an extra set of eyes to make sure we are getting to the right patients in the fastest possible time. Essentially we’re working in support of the teams within the NWAS control centre, it’s a great example of collaborative working.”
The system used to identify severely injured children during the head injury trial in Sydney was collaborative too, not competitive. There were extra eyes looking for the same cases rather than one set of eyes looking at the whole state of NSW trying to find severely injured Wally across four different control centres. How can this not be better?
But this is a refinement of the system the Scots studied; putting case identification into the hands of clinicians that provide the services is the core of the system. Why does this work? I think the clinicians directly involved in provision of advanced prehospital teams just understand the services they are dispatching better. They understand the actual logistics of response and the capability that can be delivered on scene. It seems that you need more than a set of guidelines to do this sorting quickly and effectively. The “gestalt” that comes from actual provision of these services is required to lift the dispatch system to the next level.
Sydney previously had a case identification system that was world leading and is now being replicated in other places like the north of England. Sydney also had the fastest physician staffed HEMS yet reported in the world literature to go with it.
But the case identification system was switched off and the effective service area of the HEMS halved. Missed cases and delayed activations occur frequently.
So after all this, the same questions from my last post on this topic in August 2016 still apply:
“You might ask why such a hugely effective system was discontinued in the first place.
You might ask why it has not been reinstated given the subsequent evidence.
And they would be very good questions.”
[Sound of silence].
We are always interested in people’s clever thoughts on tricky topics. So hit those comments if you have things to say.
Now, the first of those papers on the paediatric tasking happening with the crew watching the screens is this one:
Garner A, Lee A, Weatherall A. Physician staffed helicopter emergency medical service dispatch via centralised control or by crew – case identification rates and effect on the Sydney paediatric trauma system. Scand J Trauma Resusc Emerg Med. 2012;20:82.
The follow-up which looked at the before and after state of play was this one:
Garner AA, Lee A, Weatherall A, Langcake M, Balogh ZJ. Physician staffed helicopter emergency medical service case identification – a before and after study in children. Scand J Trauma Resusc Emerg Med. 2016;24:92.
That paper on priority areas for HEMS research is this one:
Fevang E, Lockey D, Thompson J et al. The top five research priorities in physician pre-hosopital critical care: a consensus report from a European research collaboration. Scand J Trauma Resusc Emerg Med. 2011;19:57.
The Scottish paper (which is not at all like the Scottish play) is this one:
Sinclair N, Swinton PA, Donald M, et al. Clinician tasking in ambulance control improves the identification of major trauma patients and pre-hospital critical care team tasking. Injury. 2018. doi: https://doi.org/10.1016/j.injury.2018.03.034
That original London was this one:
Coats TJ, Newton A. Call selection for the Helicopter Emergency Medical Service: implications for ambulance control. J R Soc Med. 1994;87:208-10.
And that letter was by me and here is the reference:
Garner A. Pre-hospital and retrieval medicine clinical governance in Sydney and the inconvenient truth. Emerg. Med. Australasia. 2017;29:604-5.