Examining the Hairs on the Yak – A Good Chance for More Chat

One of the good things about research that has its own issues, is that there is lots of scope to learn from the things about it that are good, as well as those that aren’t so great. The nice thing about ongoing comment is it gives even more chances to explain why a researcher might make certain choices along the way. Every question in research has more than one way of approaching some answers. Dr Alan Garner returns to provide even more background on this particular study, which has already generated some interesting conversation and a follow-up post

It’s an excellent thing to be able to keep having discussion around the challenges related to both conducting and interpreting a trial.  These things always bring up so many valuable questions, which deserve a response. So this is not going to be quick, but I hope you’ll have a read.

Lots of things changed between the time this trial was designed and now. Standards of care change. Systems, processes and governance models change. Indeed, in this trial standard care changed underneath us. We completed the protocol and gained ethical and scientific committee approval for this study during 2003.

The world was a different place then – at the start of 2003 George W Bush was US President and Saddam Hussein was still running Iraq. There is no keener instrument in medicine than the retrospectoscope particularly when focused 12 years back. Would I have done things differently if I knew then what I knew now – absolutely. Does the trial have hairs? Looks like a yak to me and I don’t think we are pretending otherwise.

Asking Questions

Did we ask the right question? The question was pragmatic. Add a doctor and with them comes a package of critical care interventions that were not routinely otherwise available in our standard EMS system. A number of cohort studies had previously looked at exactly this question and more studies have asked it since. Even papers published this month  have examined this question although the issue often overlaps with HEMS as that is how the doctors are frequently deployed.

I might segue slightly to address dp’s question as well which overlaps here. Is it the procedures that the team performs or the person performing the procedures that matter? Dp suggests that a better study design would be to have them all use the same protocols then we compare doctors with non-doctors. Such a randomised trial has actually been done although it is a long time ago now – 1987. It is one of the classic Baxt and Moody papers and was published in JAMA.

Patients were randomly assigned to a helicopter staffed by a flight nurse/paramedic or a flight nurse/emergency physician. The flight nurse and emergency physicians could perform the same procedures under the same protocols including intubation, chest tubes, surgical airways and pericardiocentesis. By TRISS methodology there was lower mortality in the group that included the doctor and the suggestion was this might be related to how they judged the necessity for intervention, rather than technical skill. This study is well worth a read. They note that the outcome difference might have been removed if the nurse/paramedic team was more highly trained but where does this end? We then move into the question of how much training is enough training and this is an area that I think is still in its infancy. Each time you do some research your prompt a whole lot of extra, usually interesting questions.

All That Methods Stuff

Anyway, back to this paper. All analyses presented in this paper were pre-specified in the statistical analysis plan. Although the protocol paper was not published till 2013, the statistical analysis plan (SAP) was finalised by the NHMRC Clinical Trials Centre in August 2010, more than a year prior to follow up of the last recruited patients. Copies of the SAP were then provided to the trial funders and NSW Ambulance at the time it was finalised in 2010. Along the way we have presented data in other settings, mostly at the request of interested parties (such as the Motor Accidents Authority who specifically requested analyses of road trauma cases) and in retrieval reviews. This is why there has been the opportunity for extra public scrutiny by experts like Belinda Gabbe. And public scrutiny is a good thing.

And Standard Treatments?

I’m very happy to provide some reassurance that this study did not rely on junior doctors being put through EMST/ATLS and then sent out to manage severe prehospital trauma patients. Rather the trial protocol states that treatment was according to ATLS principles. In 2003 there was no other external standard of care that we could cite for trauma patient management that was widely and internationally recognised.

The specialists had of course all completed EMST/ATLS but they were also all critical care specialists in active practice in major trauma centres in Sydney with ongoing exposure to severe trauma patients. The average years of prehospital trauma management experience held by this group of doctors at the beginning of the trial was more than 12 years each. They operated to those high level of treatment standards, with regular reviews of management to make sure this was current best practice over the life of a trial that ended up being longer than we hoped.

Other Dimensions of Time

And time wasn’t a friend. Recruitment was indeed slower than planned. This is a common problem in prospective trials. Our estimates of how long it would take to recruit the required sample size were based on a written survey of the major trauma centres in Sydney in 2003 to determine how many unconscious adult blunt trauma patients they were seeing each year. This was reduced to 60% to reflect the fact the trial would recruit for only 12 hours each day (although during the busiest part of the day) and the time needed to recruit was then estimated at 3 years. We in fact planned for 4 years to allow for the fact that patients usually disappear when you go looking for them prospectively. This of course is exactly what happened but to a greater degree than we planned.

I agree it would have been nice to have the results formally published earlier. We did present some results at the ICEM in Dublin in June 2012. It is interesting to note that Lars Wik spoke immediately before me at this conference presenting the results of the CIRC trial on the Autopulse device. This study was finally published online in Resuscitation in March 2014, more than three years from recruitment of their last patient and this trial did not include a six month neurological assessment as HIRT did.   Getting RCTs published takes time. Given we did have to perform six month outcome assessments I don’t think we were too far out of the ball park.

Quokka copy 2
To keep you going, here’s a quokka who looks like he’d be up for a chat too. [Via Craig Siczak and unchanged under Creative Commons.]

Randomising in Time Critical Systems

Just to be sure that I really have the right end of the stick on the question of excluding patients after randomisation I ascended the methodology mountain to consult the guru. For those that don’t know Val Gebski he is Professor and Director, Biostatistics and Research Methodology at the NH&MRC Clinical Trials Centre in Sydney. He was our methodology expert from the beginning of planning for the trial.

When I reached the mountain top I had to leave a voice message but Val did eventually get back to me. He tells me excluding patients post randomisation is completely legit as long as they are not excluded on the basis of either treatment received or their outcome. This is why he put it in the study design.

These are essentially patients that you would have excluded prior to randomisation had you been able to assess them properly and of course in our study context that was not possible. The CIRC study that I have already discussed also adopted this approach and excluded patients that did not meet inclusion criteria after enrolment.

Prehospital studies where you have to allocate patients before you have been able to properly assess them are always going to have these kind of difficulties. The alternative for a prehospital RCT would be to wait until you know every element of history that might make you exclude a patient. How many of us have that sort of detail even when we arrive at the hospital?

Extra Details to Help Along the Discussion

The newly met reader might also like to know that the call off rate was about 45% during the trial, not 75%. This is not different to many European systems. If you don’t have a reasonably high call off rate then you will arrive late for many severely injured patients.

And of course the HIRT study didn’t involve “self-tasking”. The system randomised cases on a strict set of dispatch guidelines, not on the feelings of the team on the day. This process was followed for nearly 6 years. There was not a single safety report of even a minor nature during that time. Compliance with the tasking guidelines was audited and found to be very high. Such protocolised tasking isn’t inherently dangerous and I’m not aware of any evidence suggesting it is.

It’s reassuring to know that other systems essentially do the same thing though perhaps with different logistics. For example in London HEMS a member of the clinical crew rotates into the central control room and tasks the helicopter using an agreed set of dispatch criteria. This started in 1990 when it was found that the central control room was so poor at selecting cases, and it resulted in the call off rate falling from 80% to 50%. The tasking is still by a member of the HEMS team, they just happen to be in the central control room for the day rather than sitting by the helicopter.

A more recent study from last year of the London system found that a flight paramedic from the HEMS service interrogating the emergency call was as accurate as a road crew assessing the patient on scene. This mirrors our experience of incorporating callbacks for HIRT.

The great advantage of visualising the ambulance Computer Assisted Dispatch system from the HIRT operations base by weblink was the duty crew could work in parallel in real time to discuss additional safety checks and advise immediately on potential aviation risks that might be a factor.

To consider it another way, why is the model safe if the flight paramedic is sitting at one location screening the calls but dangerous if he is sitting at another? What is the real difference between these models and why is one presumably a safe mature system and the other inherently dangerous?

More Mirrors

I agree that the introduction of the RLTC to mirror the HIRT approach of monitoring screens and activating advanced care resources (with extension to a broader range) was a good thing for rural NSW. However they did activate medical teams into what are very urban areas of Sydney who were neither a long way from a trauma centre nor was there any suggestion they were trapped. Prior to the RLTC the Ambulance dispatch policy for medical teams was specifically circumstances where it would take the patient more than 30 mins to reach a trauma centre due to geography or entrapment. Crossover cases obviously didn’t explain the whole of our frustrating experience of recruitment, but it was one extra hurdle that finally led us to wrap recruitment up.

You can’t bite it all off at once

In a study where you collect lots of data, there’s no publication that will let you cram it all into a single paper. So there are definitely more issues to cover from the data we have. This includes other aspects of patient treatment. So I will be working with the other authors to get it out there. It might just require a little bit of time while we get more bits ready to contribute to the whole picture.

Of course, if you made it to the end of this post, I’m hoping you might just have the patience for that.

Here’s those reference links again: 

That Swiss paper (best appreciated with a German speaker). 

The Baxt and Moody paper.


The earlier London HEMS tasking paper.

The latter London HEMS tasking paper. 

Same, same? Actually different

More of the operational data from the Head Injury Retrieval Trial has just been published. By luck more than anything else this has occurred within 24 hours of the publication of the main trial results which you can find here.

Some operational data about systems used in the trial has already been published. A key part of HIRT was a dispatch system where the operational crew were able to view screens with case information as they were logged to spot patients who may have severe enough injuries to warrant advanced care. They could then use the available information or call the initiating number for further details. If the available information matched the criteria for consideration of an advanced care team, the randomisation process then swung into action. The whole idea was to streamline the process of activation of an advanced care team to severely injured patients.

A study looking at this dispatch system in the context of identifying severely injured children has already been published here. This study compared the trial case identification system with the Rapid Launch Trauma Coordinator (RLTC) system in NSW. When the trial dispatch system was operating the paediatric trauma system in Sydney performed significantly better than when the trial system was not available. This was a combination of the dispatch system and the rapid response capability of the trial HEMS. The speed and accuracy of dispatch was a key component however.

So what’s this new paper about?

In this new paper we had the opportunity to explore the HIRT data set to look at the times it took various team models to treat patients and get them to the hospital, and then through the ED to CT. The data is unique as far as I know as we had the unusual situation of two physician staffed services operating in parallel sometimes being dispatched to the same patients.

You can find the paper here.

Getting to a CT scanner in a more timely fashion than this was a way of tracking patient progress through their care. [via telegraph.co.uk]
Getting to a CT scanner in a more timely fashion than this was a way of tracking patient progress through their care. [via telegraph.co.uk]
First comment is that this appears to confirm some European data that physician teams do not significantly affect prehospital times when compared with paramedics although the intubation rate is much greater. Papers such as that by Franschman from the Netherlands make interesting comparisons with this paper. The Dutch Physician staffed HEMS system closely mirrors the HIRT rapid response system in time intervals (and many other factors too). The fact that we have such similar results half a world apart suggests some generalisability of the data.

So are there some differences?

This study did show some differences between the physician teams in those time markers through the patient pathway. It’s worth making a couple of comments that might help to interpret that data.

This is not about individual performance but about systems. There were doctors and paramedics who worked across both systems. Their times followed the pattern of the system they were operating in on any given day.

If you look in the study discussion, the two physician HEMS systems are quite different. The Greater Sydney Area (GSA) HEMS forms part of the State ambulance helicopter system. It has to be all things to all people all the time. They have a wide range of tasks including interfacility transports, hoisting operations, ECMO and IABP transfers etc and they may potentially be tasked anywhere in NSW and perhaps up to 100nm off the coast. By necessity they are multirole and they have to be able to respond to any of these mission types when the phone rings without any notice.

The rapid response HEMS system that was set up for the trial is not constrained in the same way. It is a specialist service where every mission follows the same basic pattern. This data indicates that it is very, very good at doing one thing. Indeed as far as I am aware the scene times for intubated patients are the fastest achieved for a physician staffed HEMS anywhere in the world, even slightly faster than the published data from the Netherlands. The price of specialisation however is that this service cannot perform the range of tasks that the multirole GSA HEMS undertake.

Put simply the services are not interchangeable. The data indicates that the specialist rapid response model will arrive at patients first compared with the multirole GSA HEMS model anywhere in the greater Sydney area, except at the extreme edges of their operating range where rural bases may be faster, or within a couple of km of the GSA HEMS Sydney base.

The differences also apply to scene times where the HIRT rapid response system had scene times of half that or less observed in the GSA HEMS teams, even when confounders such as entrapment and requirement for intubation were considered. We speculate on some reasons for this such as the relative team sizes for the two operations. There may well be advantages in highly familiar teams. There is certainly some evidence for this in other areas of medicine.

What do we make of this?

Overall however I think specialisation is the key. If we again compare the HIRT rapid response model to the Dutch physician staffed HEMS system the similarities are striking. Like the HIRT system, the Dutch only perform prehospital cases, they only operate within a limited radius of their operating base (including urban areas) and they do not have hoists. Like most European HEMS they have small team sizes. And their times are remarkably similar to that achieved by the HIRT HEMS system in our study. It is all about how the services are structured and their role definition which makes them good at what they do.

There are clear implications for the task allocation system in Sydney from this data.

The current pattern of tasking appears to allocate physician teams primarily on who is closest. This allocation only makes sense if the two teams are interchangeable in capability. This is very clearly not the case. The two systems are quite different. The relative strengths of each service should be taken into account in the dispatch policy so that patients will get the most rapid and most appropriate response possible given their location and clinical condition.

The patient doesn’t care who started out closer. They want the service they need for their situation. The different strengths of the two services should form a complimentary system that ensures the fastest and highest quality care to patients, whether they are on the roadside, already in a smaller hospital, at the base of a cliff or on a ship off the coast.

What about dispatch?

The evidence from this study combined with the previous study on the Sydney paediatric trauma system also indicates that the HIRT case identification system significantly outperformed the RLTC in both speed and accuracy.

The trial case identification system operated for nearly 6 years without a single report of any type of safety incident, even of a minor nature. Once the RLTC came into being in 2007 the RLTC and HIRT systems operated collaboratively to identify severely injured children and ensure a speedy response. When HIRT identified a paediatric case, they checked with RLTC who retained tasking control to ensure that there was no additional information or competing tasks that might affect the dispatch decision. In this way Ambulance retained central control and oversight of the system and a double up of tasking to paediatric patients was averted. This would seem to be the ideal system with patients benefiting from the increased speed and accuracy of the parallel case identification process when the HIRT and RLTC systems were operating together, but Ambulance retaining central control so that competing tasks could be balanced. The HIRT dispatch system was however discontinued in 2011 when the last patient was recruited into the trial.

The practical difficulties of applying this level of sophistication to resource allocation, given the sheer volume and variety of demands on the centralised despatch system, need to be acknowledged. Nevertheless it might be time for a rethink.

Here’s those references again:


The comparison of dispatch systems in paeds patients.

The times paper.

The Dutch study.



HIRT – Studying a Non-Standard System that Ended up as Standard

There’s always a bit of extra reflection you can’t include in the discussion of a research paper. Dr Alan Garner reflects more on some of the challenges of doing research in prehospital medicine. 

The main results of the Head Injury Retrieval Trial have now been published on-line in Emergency Medicine Journal. We have paid the open access fees so that the results are freely available to everyone in the spirit of FOAM. This was an important study that was eagerly awaited by many clinicians around the world.

The summary from my point of view as the chief investigator: an enormous opportunity wasted.

It is now nearly ten years since we commenced recruiting for the trial in May 2005. Significant achievements include obtaining funding for a trial that was ultimately to cost 20 million Australian Dollars to run. I am not aware of another prehospital trial that has come anywhere close to this. Hopefully this is a sign that prehospital care is now seen as worthy of the big research bucks.

In the subsequent ten years world events have helped to drive increasing investment in prehospital trauma research, particularly conflicts in Iraq and Afghanistan and the perception that there were many preventable deaths.   The US government has become a big investor in prehospital research that might lower battlefield mortality. The Brits on the other hand typically made some assumptions based on the evidence they had and got on with it. Higher levels of advanced interventions during evacuation as exemplified by the British MERT system in Afghanistan seem to be associated with better outcomes but the evidence is not high quality.

I am the first to acknowledge that randomised trials are inherently difficult when people are shooting at you. Most prehospital care is not quite that stressful but there remain significant barriers to conducting really high quality prehospital research. Taking the evidence you have and getting on with it is a practical approach but it is not a substitute for meticulously designed and executed high quality studies. Such studies often disprove the evidence from lower level studies. We all bemoan the lack of good data in prehospital care and recognise the requirement for better research.

When you’re only left with signals

The Head Injury Retrieval Trial taken in this context really is an opportunity wasted. There is a strong signal in the as-treated analysis of unconscious trauma patients that there is a significant difference in mortality associated with physician prehospital care. The Intention to treat (ITT) analyses was not significant however.

The potential reasons for the lack of difference in the Intention to Treat group is really best appreciated by looking at the difference in intervention rates in Table 2. Both treatment teams (additional physician or paramedic only) could intubate cold so we only report the rate of drug assisted intubation. This was by far the most common physician only intervention, and the one we have been suspecting to make the most difference to head injured patients. When you look at the rates receiving this intervention it was 10-14% in the paramedic only group due to the local ambulance service sending their own physician teams in a good percentage of patients, compared with 49-58% in the treatment group. If this really is the intervention that is going to make the difference, our chances of demonstrating that difference are not great unless the treatment effect is absolutely massive.

When the system you study changes

The Ambulance Service in NSW decided two and half years into the trial that they considered physician treatment to already have sufficient evidence to make it the standard of care. They partially replicated the trial case identification system to enhance identification of patients that they believed would benefit from dispatch of a physician (there’s more detail in the HIRT protocol paper).

This is not the first time that such a thing has happened. In the OPALS study of prehospital advanced life support in Canada in 2004 the original study design was a randomised trial (Callaham). It was however done as a cohort study owing to the belief of paramedics that it was unethical to withhold ALS despite absence of proof of its efficacy. We bemoan the lack of evidence but belief in the efficacy of established models of care make gathering high quality evidence impossible in many EMS systems. NSW has proved to be no exception.

Sydney remains a good place to do this work of course.
Sydney remains a good place to do this work of course.

Where are we then?

So where does this leave Sydney? I think a quote from Prof Belinda Gabbe best sums up the situation. Prof Gabbe is a trauma researcher from Monash who has published much on the Victorian trauma system and was brought in as an external expert to review the HIRT outcome data during a recent review of the EMS helicopter system in New South Wales. Her comment was:

“As shown by the HIRT study, physician staffed retrieval teams are now an established component of standard care in the Sydney prehospital system. The opportunity to answer the key hypothesis posed by the study in this setting has therefore been lost and recommendation of another trial is not justified. Future trials of HIRT type schemes will therefore need to focus on other settings such as other Australian jurisdictions, where physician staffed retrieval teams are currently not a component of standard care”.

The only jurisdiction in Australia with enough patients to make such a study viable that does not already use physicians routinely is Victoria. Such a study would be particularly interesting as the recent randomised trial of paramedic RSI from that state found absolutely no difference in mortality, the area where the HIRT trial indicates there well may be a difference. Any potential trial funder would want some certainty that history would not repeat itself in the standard care arm however.

In NSW though, the question of whether physician care makes a difference to patient outcome is now a moot point. It is now the standard of care – HIRT has definitively demonstrated this if nothing else.   All we can do now is determine the best way of providing that care. We have more to publish from the data set that provides significant insights into this question so watch this space.


In case you missed them above:


The HIRT Protocol Paper

Callaham M.   Evidence in Support of a Back-to-Basics Approach in Out-of-Hospital Cardiopulmonary Resuscitation vs “Advanced” Treatment. JAMA Intern Med. 2015;175(2):205-206. doi:10.1001/jamainternmed.2014.6590. [that one isn’t open access]

A Bit About Paeds Trauma for Those Who Do A Bit of Trauma

This is a post put together by Dr Andrew Weatherall as background preparation for a talk at the SPANZA Paeds Update from March 14, 2015. This is an update for the occasional paeds anaesthetist. It’s not about covering it all but hopefully there’s a few useful points in there to prompt a little thought and discussion.

For lots of people who do a bit of paediatric care, there’s a bit of nervousness around little people. It’s a bit disproportionate to the numbers of actual cases of course because paeds trauma is not common. In fact, rates are slowly going down.

There is also a common paediatric conundrum to deal with – what do you do with adult evidence? This is because overwhelmingly trauma literature deals in the bigger, smellier version of Homo sapiens.

So the challenge is to provide a refresher on something that is getting less common for most of us, using evidence for other patients.

This might be easier with a story, weaved from a bit of experience and not that much imagination.

Crash copy

The Call Comes In

You get a call from the emergency department that they are expecting a paediatric patient from a crash, not too far from your hospital out on the far edges of the city. The road speed limit is around 80 km/hr and they have a 6 year old child who was sitting in the rear right passenger seat, in a booster seat. He’s probably too small for this booster seat. It doesn’t look like he was well secured.

The child was initially GCS 12/15, with a heart rate of 145/min, BP 85/58, a sore right upper quadrant, and a deformed right upper leg. Initially SpO2 was 96% but is now 100% on oxygen.

Where Should They Go?

Of the schools of thought (big kids’ centre vs place where they do lots of trauma but not lots of kids), NSW has gone for the hospitals with the pretty waiting rooms.

Probably the most relevant local research on the topic is from Mitchell et al. who looked at trends in kids going to paeds trauma centres or elsewhere. They found kids getting definitive care at a paeds trauma centre had a survival advantage 3-6 times higher those treated at an adult trauma centre.

There are issues with this. Mortality as a sole marker when you’re only discussing about 80 kids across 6 years may not be the most reliable marker of quality care. You only need one or two cases to shift from one column to the other to significantly skew the picture.

Possibly the more significant finding was the delay created by making that one stop. Stopping at another hospital (even within the metropolitan area) delayed arrival at the paediatric trauma centre by 4.4-6.3 hours. Early discussions to transfer obviously need to become a priority.

In NSW, the policy is now for ambulance officers to go directly to the paeds trauma centre if it’s possible within 60 minutes. Unless they don’t think they’ll get there.

The impact on the doctor working outside the kids trauma centres is two-fold:

  • There’s less paeds trauma to see.
  • The paeds trauma you do see will be the bad stuff.

Great mix.

The room with the international colour coding of "kids bay"
The room with the international colour coding of “kids bay”

At Emergency

So the patient, let’s call him  Joe, arrives. For the sake of discussion I’m going to assume he did come to the paeds trauma centre, but there’s a whole separate (possibly more interesting) scenario you could think through where he goes to a smaller metropolitan hospital.

Joe arrives with an IV cannula in place and Hartmann’s running. He has a hard cervical collar in place. His GCS has improved to 14/15 (he’s closing his eyes but he seems a little scared) but his heart rate is now 155/min and his BP is 78/50. Peripheral oxygen saturations are still 100% on oxygen (they were 96% off oxygen). He is sore and tender in his right upper quadrant just like they promised. That right femur does look broken. There’s also a lump on the right side of his head, towards the front just on the edge of the hairline.

The New Alphabet

We all remember the alphabet, whether  first drummed in by the fluffy denizens of Sesame Street, or mostly embedded by a trauma course. A then B then C.

Anyone working in trauma knows this is only the older version. So 1900s. The trauma alphabet now has a bunch of variations (C-A-B-C,  MH-A-B-C, choose your edit) to highlight the need to think about arresting blood loss early.

A lot of this shift in thinking is surely related to the vast amount of knowledge gained in managing trauma from military conflict where stopping haemorrhage is one of the most effective things you can do to save lives.

The causes may be different (especially in kids), but some of the thinking can be transferred.

This makes sense not just because bleeding is not great for patients. It’s also because many of the measures required to stop it take more than a couple of minutes. Not so much in the case of tourniquets or fancy dressings that make you clot. Things like surgery, or interventional radiology, or blood product management.

If you’re an occasional paediatric trauma practitioner, there’s a few points worth remembering if you’re going to elevate the importance of haemorrhage control, even while getting the other stuff done:

  • Find the blood early – better rapid diagnostic options, particularly ultrasound, need to be deployed early to figure out where blood loss might be happening.
  • Decisions need to support stopping bleeding – if the patient is bleeding, it is more than a bit important to progress continually towards making them not bleed. This is particularly relevant to arranging radiology and surgery as quickly as possible where indicated.
  • Transfusion – bleeding patients don’t need salty fluids. They need blood. And given what we know about acute traumatic coagulopathy, they probably need it in a ratio approaching 1:1:1 (red stuff: plasma:platelets).
  • Give TXA – after CRASH-2 and MATTERs, tranexamic acid has also made it to kids. A fuller discussion is over here (and there’s also the Royal College of Paediatrics and Child Health thing here though as I mention in that other post, I think they’ve got the doses not quite right).
Set 1 from The Children's Hospital at Westmead Massive Transfusion protocol (obviously, check local policies).
Set 1 from The Children’s Hospital at Westmead Massive Transfusion protocol (obviously, check local policies).


And here's the next delivery pack. (And check it out in full context, don't just rely on this screengrab.)
And here’s the next delivery pack. (And check it out in full context, don’t just rely on this screengrab.)

Joe is Getting Better

Ultrasound confirms some free fluid in the abdomen. The fractured femur is reasonably well aligned but you’ve started warmed blood products early. Joe is responding to his first 10 mL/kg of products with his heart rate already down to 135/min and a BP of 88/50. Respiratory status is stable. GCS is 15/15 and you’ve supplemented his prehospital intranasal fentanyl with IV morphine. 

You decide to go to the CT scanner to figure out exactly what is going on with the abdominal injury. Once around there Joe vomits and starts to get agitated. CT confirms a right front-temporal extradural haematoma. As he’s deteriorating you head up to theatres. 

photo 2

Now I’m going to assume anyone reading this is pretty happy with an approach to rapid sequence induction with in-line stabilisation to manage spinal precautions (not that we’d have a hard collar anyway, because those are on the way out in the draft ILCOR guidelines). We’d all agree on the need for ongoing resuscitation. I’ll also assume no one is going to stop the surgeons from fixing the actual problem while you mess about getting invasive arterial blood pressure measurement and a central line sorted.

What would be nice is some better evidence on what are the right blood pressure targets.

What BP target for traumatic brain injury?

Still, the best the literature can offer is a bit of a ¯\_(ツ)_/¯

If you look at this review from 2012 the suggestions amount to:

  • Don’t let systemic mean arterial pressure go below normal for age.
  • It might be even better to aim for a systolic blood pressure above the 75th percentile.
  • If you do have intracranial pressure monitoring and can therefore calculate cerebral perfusion pressure, then aim for > 50 mmHg in 6-17 year olds and > 40 mmHg in kids younger than that.

Hard to escape the thought we need more research on this.

The Rest of Joe’s Story

Everyone performs magnificently. Joe’s extradural is drained. His femur is later fixed and his intra-abdominal injuries are managed conservatively. The next most important thing might just be that you remembered to give him good analgesia.

Not Forgetting the Good Stuff

I might have some professional bias here, but I think remembering analgesia is just as important as the rest of it. Studies like this one suggest surprisingly high rates of PTSD symptoms even 18 months after relatively minor injury (38% though it was a small study). Although the contributors to PTSD are complex there is some evidence (certainly in burns patients)  that early use of opioid analgesia is associated with lower rates of PTSD symptoms.

This stuff matters. A kid with PTSD symptoms is more than just an anxious kid. They are the kid who is struggling with school, struggling with social skills and generally struggling with the rest of the life they were supposed to be getting on with. Pain relief matters.

So it is worth prioritising good analgesia:

  • Record pain scores as a vital part of the record.
  • Block everything that is relevant (no child with a femur fracture should have an opportunity for a femoral block of some description missed).
  • Remember treatment as analgesia (don’t just leave the fracture like you found it, for example).
  • Give rapidly acting,titratable drugs as a priority with regular checks of efficacy.
    • For example, fentanyl 5 mcg/kg in a 10 mL syringe gives you 0.5 mcg/kg/dose if you give 1 mL at a time. Do this and reassess every 3 minutes.
    • Likewise, ketamine 1 mg/kg in 10 mL provides a dose of 0.1 mg/kg each time you give 1 mL (though some would say you should use midazolam to offset dysphoria too).
    • Don’t forget novel options – methoxyflurane anyone?

The Wrap

Paeds trauma may not be as common, but it needs to be done to the same high standards we expect of trauma care anywhere. Most of the stories in resuscitation are well worn tales. But there are a few things to really take away:

* Think about doing everything to stop bleeding early.

* More blood for resuscitation, but more sensibly too.

* Never forget pain relief.


And with any luck, most of this is already old news.


Postscript: Just after I put this together, the always excellent St Emlyn’s blog put up something covering the latest changes to APLS teaching. To my immense relief a lot of it is the same. It’s worth checking out.

After the postscript: This isn’t designed to be too prescriptive and everything should be figured out in local context. Obviously any thoughts anyone has to share would be very welcome. 

A Bit of New Evidence on Drowning

An opportunity for a quick post to point to a new publication with something useful on drowning. From Dr Alan Garner.

Unfortunately we attend a number of paediatric drownings in the Sydney area every year. Many recover well. Some do not. Some do unexpectedly well. We have had a patient who was GCS 3 at our arrival and asystolic on the monitor make a full recovery. Most children in this situation however either die or are severely impaired.

This brings us to a vital question – when is it reasonable to stop resuscitation? Well, here’s some evidence to help inform the chat.

The Dutch Study

Over at the BMJ a new paper has just hit the screen:

Outcome after resuscitation beyond 30 minutes in drowned children with cardiac arrest and hypothermia: Dutch nationwide retrospective cohort study. 

This study is a nationwide observational study in the Netherlands of children with cardiac arrest due to drowning. The authors have put together ten years of data collected in a country with more than 30 million people. It seems unlikely we’ll see a bigger study.

The study indicates that no child resuscitated for more than 30 minutes had a good outcome. There were good outcomes in those resuscitated for less than 30 minutes.

This matches our experience. Our patient with the GCS 3/asystole combination and a subsequent good outcome had a return to spontaneous circulation while still on scene.

The other point of interest is that it is from an environment where water temperature is presumably a fair bit colder than the coastal fringes of Australia, but the results would appear to be similar.

It would appear that discontinuing resuscitation after 30 minutes in those with no neurological improvement or stuck in asystole is a reasonable practice.

It still comes down to time.