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.
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 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].
Notes:
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:
We can debate the value of this advanced team model vs that advanced team model. We can debate videolaryngoscopy vs direct laryngoscopy for days. People do. Its all chump change compared to the real challenge. Getting that team where they need to be. Dr Alan Garner and Dr Andrew Weatherall have a bit reviewing a paper they’ve just had published trying to add to this discussion.
You may just have noticed that there are things happening in Brazil. They are called Olympics and they are a curious mix of inspiring feats of athleticism and cynical marketing exercise inflicted upon cities that can probably barely afford them and which will be scarred for a generation afterwards. I’d hashtag that but it turns out the IOC will take you on if you mess with their precious sponsor money.
Now, you might think the obvious segue from a mention of the Olympics at the start there would be to mention drugs. The sort of drugs that enhance performance. It’s just that this feels too obvious. We’d rather make a very tangential link to kids. In particular, let’s talk about kids who are very, very injured.
The Teams
One of the bits of the Olympics that is a bit fascinating is the logistics of getting highly specialised teams into the right place at the right time in the sorts of cities that don’t usually get anything to the right place at the right time.
Maybe this is unfair but I don’t immediately think “super efficient transport infrastructure” when I think of Rio de Janeiro. And when I’m on a commute in the early hours of a Sydney workday, the fact that anyone was able to get a rowing team out of the stacking rack and to a patch of water in the hillock-shaded nirvana of Penrith during our local Olympics is astounding.
That’s kind of central to the whole circus though. Everyone is getting their right team to the right start line at the right time. It would probably be more entertaining if you dropped the table tennis team at the volleyball court but that’s not how it works when you’re trying to get the best of the best doing what they are built for.
Which is the cue to make this lumbering patchwork monster lurch back to the segue.
Right Place, Right Time
Advanced EMS needs to achieve the same goals of right place and right time. (Never said it would be a pretty link, but there it is.) Whatever your model of staff might be for delivering advanced prehospital care (paramedic/physician, paramedics across the board, St Bernard with an alcohol supply) there would be no one who doubts that the key to the whole thing is to get them to the right jobs at a time when those advanced skills have a role in making a difference.
You might be able to put one of those snorkels in the airway hanging upside down while drilling an intraosseous with particularly agile toes but if you’re back at base that’s not going to help the patient out there who is injured.
For a while now we’ve been really exercised by that problem. How do we make the tasking process better? Because tasking is not about the team at base. It’s not about which location the vehicle comes from. Tasking is always about the patient waiting for the care they need. They’re just wishing you’d been waiting there already, not still somewhere else.
That paper suggested that when you had a team actually delivering HEMS involved in identifying and tasking of cases, they were far more likely to identify cases where their skills might help (meaning they were more likely to identify cases of severely injured kids from the initial emergency call information in the system) than a single non-HEMS tasker working away in the office.
The involvement of the HEMS team got removed though, so it seemed timely to revisit this area to look at the time before the changes where the two systems worked together and the subsequent time period where it was just left to that one paramedic in the office.
Kids and the NSW System
It is going to help you to know a bit of background here. For a while now in New South Wales, there has been a stated goal in the trauma system to get kids straight to a paediatric trauma centre (PTC). Interest in this first came about because of overseas evidence that maybe this was the best option for kids. This was later followed by local work. This established that kids who went to other centres before the PTC tended to wait a long time in the first place they went to. Like 5 hours in that initial hospital before there was any movement.
Another study also suggested that kids who went to an adult trauma centre first had 3 to 6 times the risk of a bad outcome. And by bad outcome I mean a dying sort of outcome. Now, there are issues with being too firm on those numbers, particularly as not many kids die from traumatic injuries over any measured time period in our system so one or two kids surviving in the adult centre would make a big difference to those stats. But these were the sort of figures that made people keen to get kids straight to the specialist kids centres.
So the system is supposed to be designed to get kids to the kids’ hospitals as a priority. Do not pass go, do pass the adult centre.
Around the same time as that was becoming a talking point, the Head Injury Retrieval Trial was getting moving. As part of that trial, there was an agreed setup for the HEMS crew (including the aviators) to have access to the emergency call info on the ambulance computer screens on about a 90 second delay from when it hit the ambulance system.
For the trial (only adults), you’d look at the highest urgency trauma cases and look for specific trigger mechanisms which would lead to a protocolised response – either an immediate decision to randomize or a callback and interrogation step.
For kids, a different request was made. The request was just to respond to severely injured kids (where it seemed like the severity matched the initial call info or the mechanism was a super bad one; something like “kid vs train” for example). No randomisation as they were not in the trial; we just went.
So the crew screened for paediatric cases too, as requested. And went to paediatric cases. There was some real learning in that too, as the HEMS crews started making it to a much higher proportion of severe paeds trauma (and drowning) than had historically been the case. This was partly due to the higher rate of recognition of cases, and partly due to the fact that the HEMS team was really fast getting to the patient, arriving before the road paramedics had already moved on. You can read more about the kind of time intervals the HEMS team achieved here. As far as we are aware from the published literature the whole end-to-end process was the fastest ever reported for a physician staffed HEMS system, while still offering the full range of interventions when indicated.
Mirror, Mirror
A third of the way through the HIRT thing happening, the ambulance service introduced a role within ambulance which hadn’t been there before. The Rapid Launch Trauma Coordinator. Their role? To look at the screens as jobs came in and try to identify cases where advanced EMS might help.
As it turned out they elected to include the trial area as well as other areas in the state in the roving brief for this paramedic sitting in at the control centre. While that was an issue for the trial, for kids it was just a bonus, right? Another set of eyes trying to find kids who might need help sounded perfect.
The bonus in kids was that there was no need to try and have the person doing the RLTC work blinded to whether the case had been randomised or not, so if the HIRT crew in their screening saw a case with a kid, they’d call quickly and see if the RLTC knew of a reason they shouldn’t go. It was a nice collegial cross-check.
This also ensured that only one advanced team went unless they thought there were multiple casualties (in the trial double tasking was common due to the blinding of the RLTC to the randomization allocation). So the cross-check avoided double ups and maximized use of resources too.
Well how close to being the same are they then?
It was in this context of the systems for screening cases operating alongside each other that the first bit of research was done [2]. Over a two year period cases with severely injured kids occurring while the HEMS was available were reviewed to see if either screening process picked them up.
There were 44 kids fitting that bill (again, the numbers are low in the Sydney metro area). 21 weren’t picked up by anyone. 20 were picked up by that HIRT crew and 3 were picked up by that person working on their lonesome in central control.
When you looked more broadly at times the HIRT system wasn’t available compared to those it was, the proportion of patients directly transferred to the PTC was much lower. This fits with other stuff showing that advanced EMS teams tend to be more comfortable bypassing other sites to make it to a PTC, while also performing more interventions.
Another thing this research threw up was to do with time of a different kind: when HIRT was available the median time to reach the PTC was 92 minutes, compared to 296 (nearly 5 hours again) when they weren’t available.
So on that first round of research the message seemed to be that there was something about that case screening process that picked the severely injured kids more often. Maybe it was the extra eyes and regular rotation. Maybe it was better familiarity with the nature of the operational work for advanced EMS on the ground. Either way that screening process seemed to support the goals of the trauma system pretty well.
Things You Take Away
Come March 2011, the screens were taken away from the HIRT set-up as the trial wrapped up. No more screening by the actual HEMS crew. Back to centralised control screening back in the office.
As the HIRT screening process seemed to have such a dramatic effect on the trauma system in Sydney we wanted to keep it going as did the trauma people in the Children’s Hospital at Westmead. They had particularly noted the change as by virtue of geography they are the closest kids centre to most of the Sydney basin. The increase in kids arriving straight to the ED even led them to revise their internal trauma systems. But away the screens went.
So the question for this subsequent bit of research was really pretty simple: did we lose anything going back to the centralised process alone? More crucially, do the patients lose anything?
Comparisons
This time the comparison wasn’t the two screening processes working alongside each other. It was before and after. What didn’t change was the sort of paeds patients being looked for. It was any kid with severe trauma. This might include head injury, trunk trauma, limb injuries, penetrating injuries, near drownings, burns and multi-casualty incidents with kids involved.
So in the ‘before’ epoch there were 71 cases of severely injured kids (covering 34 months) that fitted the bill. For the ‘after’ epoch there were 126 cases (over 54 months).
In the ‘before’ epoch with the systems working alongside each other, 62% of severely injured kids were picked up and had an advanced EMS team sent.
In the ‘after’ phase? It fell. To 31%.
And while the identification rate halved it also took kids longer to reach the PTC going from 69 to 97 mins. 28 minutes might seem small but then most of us have probably seen how much can change in a severely injured patient in less time than an episode of Playschool runs for.
Things that didn’t change? Well the overtriage rate for the CareFlight crew was pretty much the same. And whether advanced EMS teams or paramedic only teams reached the kids, their respective rates of transfer direct to PTC were pretty much the same as in the ‘before’ time. It seems that once crews get tasked they treat the patients much the same as their training sets them up to do.
It certainly seems that the right team in our system is a physician/paramedic crew (in NSW the doctor/paramedic mix is the advanced EMS set-up used across the board) as the kids get much more intensively treated at the scene and then get transported directly to a kids centre. In other words faster access to advanced interventions and much faster access to the specialist kids trauma people. Right team to the right patient at the right time.
The Washup
So we’re left with a few things to consider. There is an acceptance locally that severely injured kids are more likely to get time critical interventions if an advanced EMS team is sent (and advanced EMS teams could come from different backgrounds in different places, it just happens to be physician/paramedic here). There is a belief that those who’ve had that extra training and exposure will feel more comfortable with kids, who can be challenging.
The system has set a goal of getting those advanced teams to severely injured patients, and in this case we’re talking about kids. These two papers suggest that a model where those who are directly involved in advanced EMS are part of the screening process will identify more severely injured kids and get more of them straight to the PTC and definitive care.
Should this be a surprise? As the paper mentions this isn’t the only example of a model where clinicians who do advanced EMS work being part of the screening process seems to be a success above and beyond those who specialise in screening all calls. It may be that knowing the lay of the land when it comes to service capability counts for a whole lot. There is also work suggesting that telephone interrogation of the emergency caller by a flight paramedic is accurate when compared to assessment by on-ground ambulance crews when trying to figure out whether advanced care might help.
This was the experience with the HIRT screening process too, where structured callback was part of the game. The HIRT system also had some unique features. It is the only one we have heard of where the crew sitting next to the helicopter identified the cases they responded to. This seemed to create added benefits in shortening the time to getting airborne because parallel activities come to the fore (see the paper for more). A very consistent six minutes from the beginning of the triple zero call (emergency call from the public) to airborne is pretty quick.
Does this have any implications for adults too? Back in 2007 when the RLTC was introduced the local ambulance admin made the decision that sending advanced EMS teams to severely injured patients was the standard in Sydney and the RLTCs job was to make that happen. From the time the RLTC started till the screens were removed in March 2011 the HIRT system identified 499 severely injured adults. The RLTC also spotted 82 of these, or 16%. So the HIRT spotting system appears to be even more effective for adults than in kids.
Right now there are a bunch of different advanced EMS teams in Sydney, all wanting to get to that right patient and offer top notch care. Those patients would be very happy to have teams with the full range of skills coming. And all those teams have the skills to add the sort of screening that involves protocols that operated during HIRT. They’re sitting waiting for someone else to look their way.
So let’s work it through again.
Let’s say you were trying to meet that thorny challenge of right team, right place, right time. Let’s say you had ended up trying out a screening system similar to some others around the world but with some tweaks that made it even better, particularly for local conditions.
Let’s say that system hugely improved the way that severely injured kids were cared for. Let’s say that system was also even better at spotting severely injured adults too. Let’s say that system was part of the fastest end-to-end physician HEMS system yet described in the world literature.
Let’s say when you moved away from that screening system you didn’t pick up as many of the severely injured kids as you wanted to so they missed out on early advanced care, the kids didn’t get to your preferred destination first up as often and they took longer to get there.
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.
Notes:
The image of Charlie in his guises was on the Creative Commons area of flickr and posted by Kevin O’Mara. It’s unchanged here.
The Collective 