Tag Archives: trauma

All the Small Things – A Short Thing on Big Trauma in Little People

May 19, 2018 careflightcollective 1 Comment

Somewhere around Sydney at the recent ANZCA Annual Scientific Meeting, Dr Andrew Weatherall had the chance to kick along a discussion about trauma in kids. This is the post version of things covered and things in the chat. This is also cross-posted over at the kids’ anaesthesia site.

Let’s start by keeping in mind a very, very important point: it’s probably not possible to find anyone near a conference meeting room in Sydney on a Thursday who is likely to be a true expert in paediatric trauma, particularly in anaesthesia. True paediatric trauma experts, the ones who know the literature backwards and have an amazing array of personal experiences that have refined their approach, are a rare, perhaps even non-existent, species.

That’s not a statement trying to offer up an excuse or throwing shade anywhere else. It’s just stats. If you look at the most recent Trauma Registry report out of NSW, our most populous state in Oz, you’ll get a chance to look at the 2015 collated serious trauma stats. For the whole of that year, across the whole of the state, there were 225 kids who got to hospital with serious injuries. 225 across the three kids’ trauma centres. Now spread that across all the people who work there and ponder how many people are likely to get the sort of exposure to get really good.

There just can’t be that much exposure. And if people tell you they see heaps, well, I reckon they probably don’t.

Which I guess means that everything that follows here should be held up to really serious scrutiny. Check the references. Size it up. See if it holds water. Add another cliché here.

The attendees at this session came from a variety of anaesthetic backgrounds from the level of student to very experienced. For most of them the main theme seemed to be ‘I don’t really feel comfortable with kids’ trauma [“Phew,” I thought, “me too”] and I don’t really get to see it much. But when I do it’s usually bad.’

This is common in lots of places. In NSW, prehospital organisations are directed to drive past hospitals and go on to a designated kids hospital with an injured child they’ve picked up unless they genuinely think that child is about to die. So if they pull up at your joint, it’s bad.

The aim here is to start with a story. In that story we’ll get to cover a range of things about kids’ trauma. It probably won’t be earth shattering. It should be practical.

So let’s get to it.

The Place

Let’s start with a standard day at your local anaesthetic joint. It’s your favourite hospital at Mt Anywhere. Like most Australian “mountains” it is, in fact, a very poor excuse for a mountain and actually “Anywhere” is really “somewhere”. I’m just being vague about the somewhere.

Let’s say it’s a solid-sized place on the edge of a metropolitan area. There is plenty of adult surgery, the occasional elective paediatric list of some sort. The place has a neurosurgeon but not necessarily continuous coverage and big kids’ stuff goes elsewhere.

You get a call from the ED because they have received a call just a few moments ago. A prehospital crew out there somewhere near Mt Anywhere have picked up a kid. This kid is 6 years old and thought to be about 26 kg. They have had an altercation with a dump truck. Ouch.

The initial assessment is that this kid is pretty unconscious with a GCS of 6, which seems not that surprising because there is a fair bit of swelling around the left eye like they took a hit. Their heart rate is 128/min, they have a blood pressure of 95 mmHg systolic. Happily when they checked peripheral saturations they were in the high 90s and they can’t find anything on the chest. They added oxygen anyway. They also placed an intraosseous needle. They are on their way. You have 10 minutes.

Big Question Number 1

So at this point the question I asked was “What are you worried about?”

I think the response was “It’s a kid. Everything.”

And then more seriously:

There were worries about the injuries themselves. Head injury was thought to be likely. The heart rate might point to bleeding somewhere and kids can compensate for a bit before they fall off a cliff.
There were some who were worried about their ability to do technical things in kids. Challenging at the best of times if you’re not doing it regularly, everyone was pretty unanimous that the situation was unlikely to elevate their performance.
What can we do here?

This last one was an excellent point. A kid with big injuries should ideally be going somewhere dealing with critically ill kids all the time. If you think there’s a good chance they’ll have to go elsewhere there should be absolutely no one in the system who would mind if you called retrieval before the patient even arrives so they can start thinking about plans. You might even find they have useful ways of supporting you and they can get things rolling if retrieval will be needed.

Arrivals

The patient turns up and they are basically as advertised. The obs are the same. The left upper arm looks wrong enough that you’re thinking “that’s a fracture”. The patient is a bit exposed and there’s some bruises down the left side of their abdomen.

Question 2 is pretty obvious; “what first?”

Or perhaps the better way to phrase it is “What next (and how is it different because it’s a kid)?”

The discussion pretty much came down to the following (there’s a bit of abridging here):

‘I’d use the team to assess and treat with an aim to get as much done at the same time as possible.’
‘I’d assess the airway and maintain C-spine precautions.’
‘I’d assess breathing and treat as I needed to.’
‘I’d get onto circulation, try to get access, and if I needed fluids try and make it blood products early rather than lots of crystalloids.’
‘I’d make sure we complete the primary survey and check all over…’

Now, you probably noticed that all of these things are just the same things as everyone would say for adults. Maybe it turns out they are just litt… wait, I’m not supposed to say that.

There’s a point worth noting though. If you are going to have to face up to kids’ trauma and there are things that worry you, it’s also worth noting the stuff that is close to what you are more comfortable with. There will always be basics you can return to.

Now the discussion did touch on things around the topic of how you’d go about induction of anaesthesia and intubation. There were no surprises there with a variety of descriptions of RSI with agents that people felt they were excellent at using. A whole thing on that seems like too much to go with here but you could have a read about RSI in kids at this previous post.

Likewise THRIVE (and other forms of high flow nasal prong work) was mentioned. That’s probably beyond the scope of this post too if it’s going to stay under a bazillion words but it’s worth pointing out a couple of things that are also in this thing here and here. One is that the research that has been done that’s kind of relevant to extending apnoeic oxygenation hasn’t been done in an RSI set up and the nasal prongs aren’t generally applied during the actual preoxygenation bit.

Where to from here?

Now it’s probably time to move this along so let’s say that heart rate has improved a little to 115/minute, the blood pressure is about the same and you’ve assessed all those injuries and think facial fractures are on the cards, plus a fractured left humerus.

Oh, I should have mentioned that left pupil. The one that’s big and not doing much. The one I deliberately didn’t mention until now because I didn’t want the thing to move too quickly.

This brings us to a crucial and very deliberately placed point – what sort of imaging are we going to do?

We’re going to bench FAST as a super useful option here because the negative predictive value is somewhere around 50-63% (from the Royal College of Radiologists document) and we’re moving to a cashless society so coin tosses seem old school.

Let’s assume we’re heading to the CT scanner because there is no neurosurgeon around who doesn’t want a scan to make a plan. So how much do we scan?

I threw this to the room and there was a variety of options offered. The classic Pan Scan was mentioned. Or just the head. Or maybe head and neck. Or head and neck and abdomen but maybe not chest.

Finally we get to something that really is different in kids then. In kids the threshold for exposing the patient to radiation is a bit higher than in adults. This is because the risks of dosing kids with radiation during scans are far more significant than for adults. The ALARA principle (“As Low As Reasonably Achievable”) comes very much into play here. You can find a bit more description about this here or you can look at the Royal College of Radiology guidelines.

The headline things to remember are that if you expose a kid to 2-3 head CTs before they hit the age of 15 it looks like it might almost triple the risk of brain tumours. Make it 5-10 and that’s triple the risk of leukaemia. Abdominal and pelvic CTs give you a higher dose of radiation.

So in this context in kids there is a real second thought about what scanning to do. On top of that for things like abdominal trauma it’s much more likely in kids that the surgeons will pursue non-operative management. And while there are probably better places to delve into the minds of surgeons it’s worth spending a moment with the flowchart from the ATOMAC guidelines to try and get a sense of their thinking. Or if you look at it long enough I think it works like one of those 3D eye pictures.

What is definitely the case is that treating abdominal injuries on the basis of the grade of injury as demonstrated on scanning (for spleen and liver injuries particularly) isn’t really a thing. Early decisions are based very much on haemodynamics and clinical assessment.

So in our patient where there isn’t current clinical evidence of intra-abdominal pathology (just trust me, there isn’t) and the haemodynamics aren’t suggesting hidden pathology, then the scanning is probably just going to be looking at the head and maybe cervical spine. Plus this patient is going to start with a chest X-ray (particularly after intubation).

Lo and behold, the CT head shows a left subdural haematoma with a bit of midline shift. Time to go here…

The Goalposts

Off to theatres then and I guess the next question is:

What are the priorities for the anaesthetist here?

Everyone pretty much jumped on two:

Get on with it – meaning the thing that needs to happen to protect brain tissue is the surgeons need to do a thing. There’s not much the anaesthetists can do that will help brain tissue as much as the drilling bit in this context. Delaying for things that’d be ideal (say, an arterial line) is not really what the patient would ask for. So ‘hop to it’ was a universal endorsement.
Make sure you are giving the brain the best odds of scoring blood supply.

There was passing discussion on agents, where to have the CO2 levels, hypertonic solutions and things like that but really most of those are as per adults so people zeroed in on perfusion targets.

In kids this is a bit of a problem because there is even less good evidence compared to the adult population. This is particularly the case for blood pressures before you have access to intracranial pressure monitoring and can therefore figure out the cerebral perfusion pressure (CPP). On top of that the Brain Trauma Foundation TBI guidelines have recently been updated, but not for kids. That document still lives on from 2012 (at least for now).

When I went to check on the targets listed at The Children’s Hospital at Westmead, their CPP targets went like this:

> 10 years old aim for 60 mmHg CPP or above.
In the 1-10 year old age range aim for CPP 50 mmHg or above.
In the under 1s aim for 45 mmHg or above.

The thing is, at least when you start you probably won’t have access to intracranial pressure (ICP) to do the CPP = MAP – ICP (or CVP if that’s higher) calculations. Hence this suggestion that you should treat for a bad case scenario where ICP is assumed to be 20 mmHg because that’s when you’d step in and do something about it.

In this case you need to add 20 to your mean arterial pressure (MAP) and aim for that target. What would be kind of nice of course is having a systolic BP target. Unfortunately we don’t get that until the age of 15, where the new TBI guidelines suggest you should keep SBP above 110 mmHg.

As an aside I have some reservations about the ‘let’s just assume ICP is bad’ because assumptions seem like not the best basis for manipulating physiology. They seem even worse when you’re making a lot of assumptions about how pathophysiology will play out.

Given that TBI is associated with disruptions to the blood brain barrier and a variety of other stresses, assuming that raising MAP won’t just result in swelling, bleeding into vulnerable areas or other causes of general badness seems … fraught.

For now it’s all we’ve got though so there it is.

The Red Stuff

The surgeons do their thing of course and that means (particularly when you have certain topics to cover in a conference session) lots of bleeding. There are bigger places to go into massive transfusions in kids here, but it’s worth noting a couple of key tips:

Massive Transfusion Protocols help and emphasise the need for not just the red stuff but good amounts of a fibrinogen source (locally that’s cryoprecipitate rather than fibrinogen complex concentrates, platelets and FFP. A quick Google search will find the guideline used at The Children’s Hospital at Westmead and the breakdown of what comes first…

Pack 1

and what comes next…

Pack 2.jpeg

The number for pretty much all of the units (at least to start with) is 10 mL/kg. Quickly figuring out how much 10 mL/kg is for the patient in advance makes the calculations a lot quicker.
Of course the one different one is cryoprecipitate which is around 1 unit per 5 kg (up to 10 units).
Calcium replacement shouldn’t be underestimated as an ally (or even necessity). Perhaps me ending up mostly looking after kids just coincided with everyone getting interested in calcium, but I lean on this way more than I used to, particularly as the things that are supposed to help you clot go in.

Of course you’re not allowed to talk about trauma without mentioning tranexamic acid (TXA) because we’d all like to make sure there’s at least a little less bleeding if there’s a way we can influence it. So we want to get it there and get it here quickly.

The main question then is how much should we be giving?

Getting Bitten

The one guideline out there is the one from the Royal College of Paediatrics and Child Health. Back around 2012 they came up with a “pragmatic dosage” of 15 mg/kg as a loading dose then 2 mg/kg/hour.

I can sort of see why because there’s not a huge amount of evidence out there for ideal dosing in kids, particularly in trauma. What we end up with is evidence from other settings where traumatic damage is inflicted on tissues (i.e. big surgery).

If you go to any of those settings, like craniosynostosis surgery or scoliosis surgery or cardiac surgery, you’ll see a dizzying array of dosing regimes too. Loading doses of 10, 20, 30, 50 and 100 mg/kg with infusions any of 2, 5, 10 and 20 mg/kg/hr. This only makes figuring out what to do an awful lot harder.

So when they came up with that “pragmatic dosing” they went for a pretty cautious option. That’s partly because they’re not super sure about risks of thrombosis and there’s lots of concern about seizures with TXA loading. The theory goes that with higher doses you get higher levels of TXA in the CSF and that leads to inhibition of inhibitory glycine and GABA receptors (because they have those crucial lysine binding sites). It’s not everything but there’s at least some cohort research suggesting there’s not much association. In a retrospective study looking at craniosynostosis surgery with 1638 records examined the rate of seizures was the same across groups at around 0.6%.

The problem with that dosing option is there’s enough evidence to suggest that 15/2 is just not going to cut it. You might as well get a mosquito that bit a person who once had TXA and get them to sneeze on your patient. Bigger doses seem likely to work better.

A relatively recent paper in scoliosis surgery patients compared higher dose TXA with a lower dose. In this case the higher dose meant loading at 50 mg/kg then an infusion of 5 mg/kg/hr while low dose meant loading at 10 mg/kg then infusion at 1 mg/kg/hr.

So was there a difference? Well the lower dose crew lost an average of 968 mL and needed 0.9 units of red cells on average. The higher dose crew ended up losing about 695 mL and receiving 0.3 units of red cells on average. Unfortunately there was only 72 patients in the lower dose group and 44 in the higher dose group. So we’re left with not much.

There’s enough to suggest though that higher doses are probably required to actually influence the fibrinolytic pathway. A dose of 20-30 mg/kg to start with is much more like what I’d do (without exceeding 1 g) followed by an infusion of 10 mg/kg/hour.

The Next Bit

Look, don’t you think this has gone on long enough? Everyone did great, the surgeons operated really well and everyone got through a tough day pretty well and gave our imaginary patient the best shot possible.

There were of course other things we chatted about. Things like tricks for getting that IV access (if you remember the name Seldinger and that a 0.018” wire will fit up a 24 gauge cannula you’re in good shape). Then the challenges of spine immobilization and the role of options other than a hard cervical collar. Then of course the importance of considering the impact on ourselves when we look after these kids.

None of those deserve short change though so that can wait for some other time. Or maybe there’s an expert out there for that.

Notes:

The things on radiation risks in kids to look at would be this one:

Pearce MS, Salotti JA, Little MP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. The Lancet. 2012;380:499-505.

and this one:

Mathews JD, Forsythe AV, Brady Z, et al. Cancer risk in 680 000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ. 2013;346:f2360.

Then of course there’s the bigger Royal College of Radiology Guidelines.

Oh, and the ATOMAC guidelines would be these ones:

Notrica DM, Eubanks III JW, Tuggle DW, et al. Nonoperative management of blunt liver and spleen injury in children: Evaluation of the ATOMAC guideline. using GRADE. J Trauma Acute Care Sure. 2015;79:683-93.

Here are those Brain Trauma Foundation TBI Guidelines.

The kids TBI guidelines are here.

I can save you the Google search when it comes to that Massive Transfusion Protocol.

That RCPCH document about TXA in trauma is this one.

The thing in craniosynostosis surgery that covers seizure risk is this one:

Goobie SM, Cladis FP, Huang H, et al. Safety of antifibrinolytics in cranial vault reconstructive surgery: a report from the pediatric craniofacial collaborative group. Pediatr Anesth. 2017;27:271-81.

The high-dose vs low-dose scoliosis study is this one:

Johnson DJ, Johnson CC, Goobie SM, et al. High-dose versus low-dose tranexamic acid to reduce transfusion requirements in pediatric scoliosis surgery. J Pediatr Orthop. 2017; 37:e552-e557.

Prehospital Trauma

The Deal with Seals

March 1, 2018 careflightcollective 3 Comments

Greg Brown returns to look at an important thing relevant to first responders (and lots of other people really) – the sucking chest wound.

We’ve all been there – sitting through some kind of “first aid” training and having some kind of “first aid trainer” speaking authoritatively on some kind of “first aid style” topic. If you are like me you’ve used your time productively over the years and perfected what my wife refers to as “screen-saver mode” – it’s that look on your face that tells the instructor that you are listening intently, often supplemented by the insertion of “knowing nods” or head-tilts, but in actual fact you are asking yourself “if I was able to collect all of my belly button lint over a 12 month period and spin it into yarn, I wonder if I could make enough to abseil off London Bridge?”

Don’t get me wrong – I reckon effective and accurate first aid training should be a mandatory part of having a car / bike / truck / bus licence. More appropriately trained people should mean faster recovery rates for most injured people (and less work for overstretched first responders).

It’s just that sometimes first aid trainers teach stuff based on ‘we reckon’ or ‘that’s how we’ve always done it’ rather than evidence or knowing it works in the real world. This post is about one of those things.

“What is a sucking chest wound?”

In the Army questions come in a few different shapes and sizes. A popular one is “there is only one obscure answer you should have guessed I wanted”. Trust me, the muzzle velocity of your primary weapon is 970 metres per second.

Another popular one is “the question that should be about one thing, but is actually to demonstrate a quite tangential point”. Like,

“What is a sucking chest wound?”

For an army instructor the answer is not what you are thinking right now. It is “Nature’s way of telling you that your field craft sucks and everyone can see you and now you got shot”.

Let’s Go With the Medical One

We’re going to go with the alternative, more medical one. A sucking chest wound is defined as air entering the thorax via a communicating wound that entrains air into the space between the lungs and ribs more readily than the lungs can expand via inspiration through the trachea.

This is about pressure differentials – in order to inhale, the lungs must generate a relative negative pressure such that air can be sucked into them via the trachea. But if you make a big communicating hole in the trachea, that might become a pretty big highway for air to enter the space with the negative pressure.

The communicating hole does need to be pretty big. Depending upon which textbook you read, this hole needs to be a minimum of a half to three quarters the diameter of the trachea. Also, the patient needs to be undergoing relative negative pressure ventilation (or, in simple terms, breathing spontaneously). If they are being artificially ventilated (which requires positive pressure) then the pressure inside the lungs will be higher than the pressure on the outside of the body; the result is that air will be forced out of the intra-pleural space (or thorax) by the expanding lung (as opposed to being entrained into the thorax via the hole in the chest).

Are sucking chest wounds really that bad?

Well, yes. They suck in fact.

A sucking chest wound creates what is known as an open pneumothorax. Let’s consider the option where that hole does not seal on expiration. We’ll get onto the also very annoying sealing with a flap version in a bit.

In this slightly not so annoying case, the patient will have a ‘tidalling’ of air in and out of this communicating hole. The effect? Respiratory compromise, increased cardiovascular effort and reduced oxygen saturations. Patient satisfaction? No, not really. Death? Maybe – depends on what other injuries exist and the ability of the individual to compensate. See Arnaud et al (2016) for more details.

But if this communicating hole were to seal itself on expiration then you now have an open tension pneumothorax. Sounds bad; IS bad.

In such a case, each time the patient breathes in they will entrain air through the communicating hole in the chest wall (that whole “negative pressure” thing in action). But when they breathe out, instead of having that additional intra-pleural air tidal outwards, the flap will seal it in place; each time they breathe in, the volume of trapped air will increase and you’ll end up with the tension bit.

How much air is required? Well a randomised, prospective, unblinded laboratory animal (porcine) trial conducted by Kotora et al (2013) found that as little as 17.5mL/kg of air injected into the intra pleural space resulted in a life-threatening tension effect.

Actually, that’s a fair bit of air…for those of you who are lazy and don’t want to do the math, that’s 1400mL for an 80kg person. But remember, any tension pneumothorax (open or closed) is progressive – each time you breathe, more air is trapped; therefore, it doesn’t take long to reach crisis levels.

“But are they common enough for us to be worried about?”, I hear you asking. The short answer is yes – in fact, the long answer is also yes.

Kotora et al (2013) reviewed the statistics from the Joint Theater Trauma Registry regarding contemporary combat casualties with tension pneumothorax and found that they accounted for 3 – 4% of all casualties, but 5 – 7% as the cause of lethal injury.

“Yes, but I don’t live in a combat zone…”, I hear you say. I have two responses:

Good for you; but also,
According to Littlejohn (2017), thoracic injury accounts for 25% of all trauma mortality. And sure that stat is for all forms of thoracic injury and a sucking chest wound is but one of those but there’s a neat article by Shahani which sums up the incidence nicely and it turns out you should give this some thought.

The Table — We even saved you some time by grabbing the relevant image.

So, your field craft sucks – now what?

Now that we know that sucking chest wounds are both possible and bad, we should probably discuss treatment.

Some History

Back in the mid 1990’s, Army instructors were very big on rigging up a three-sided dressing. Unwrap a shell dressing, turn the rubbery-plastic wrapper into a sheet and tape three sides down with the open bit facing the feet to allow blood drainage.

And, in an astonishing turn of events, everyone I’ve met who tried this confirmed it didn’t really work that well.

In that Littlejohn paper they make reference to the fact that by the 2004 ATLS guidelines (which are not usually that quick moving), it was being written unblock and white that there was no evidence for or against the three-sided dressing option. It was done because it sounded good in theory, but the evidence wasn’t there.

Now to the New

Actually, not that new. Chest seals already existed.

These chest seals (at that time the Bolin produced by H & H Medical, and the Asherman produced by Teleflex medical) included one-way valves to allow for the forced escape of trapped intrathoracic air and blood. basically they took the impromptu three-sided dressing and made it a ready-made device in the form of an occlusive dressing with an integral vent.

But did they work?

Yes and no.

On a perfectly healthy (albeit with a surgically created open pneumothorax) porcine model with cleaned, shaved, dry skin they sealed well and vented air adequately.

However, once the skin was contaminated (dry blood, dirt, hair etc) the Bolin sealed much better than the Asherman. And if there was active blood drainage too (such as in an open haemo-pneumothorax) then all bets were off. Both vents clogged with blood and ceased to work. Sure, you could manually peel the seal back and physically burp the chest but if you did so the Bolin became an un-vented seal and the Asherman was as good as finished (i.e. it wouldn’t reseal). But hey, at least you had sealed the communicating hole and in doing so stopped entraining air.

“Is this the best you can do?” you may be asking. Well to be honest, since the vents didn’t work for more than a breath or two most people decided that the vents were pointless. The outcome was that we all decided to forget about the vents and just seal the wound. That way, assuming that there was no perforation to the lung, this open tension pneumothorax (aka sucking chest wound) became a routine, run of the mill, plain old pneumothorax. And if there were signs of tensioning (e.g. increasing respiratory distress, hypotension, tachycardia….) one just needed to peel back the seal and manually burp the communicating hole thus relieving the pressure. Use a defib pad – those bad boys stick to anything! Problem solved….

Or how about a newer idea + research?

In 2012 the Committee on Tactical Combat Casualty Care (CoTCCC) started questioning the efficacy of contemporary practices regarding the placement of chest seals on sucking chest wounds. It had already been accepted that the current vented chest seals had ineffective vents, so practice had changed from using a chest seal with an ineffective vent to simple, “soldier proof” unvented seals and burping them as required. Surely there had to be a better way…?

Kotora et al (2013) decided to test three of the most readily available vented chest seals in their aforementioned randomised, prospective, un-blinded laboratory animal (porcine) trial: enter the Hyfin, Sentinal and SAM vented chest seals.

What they found was that all three were effective in sealing around the surgically inflicted wounds and in evacuating both air and blood. Thus, in 2013, CoTCCC changed their recommendations back to the use of vented chest seals.

But there were still some questions:

Once life gets in its messy way, do they seal (or at least stick to skin)?
Are all vent designs equal?

To answer question 1, Arnaud et al (2016) decided to evaluate the adhesiveness of the 5 most common chest seals used in the US military using porcine models. What they found was that the Russell, Fast Breathe, Hyfin and SAM all had similar adherence scores for peeling (> 90%) and detachment (< 25%) when tested at ambient temperatures and after storage in high temperature areas when compared to the Bolin. The researchers admitted, though, that further testing was required to assess the efficiency of the seals in the presence of an open tension haemo-pneumothorax.

In response to question 2, Kheirabadi et al (2017) tested the effectiveness of 5 common chest seals in the presence of an open tension haemo-pneumothorax (again, on porcine models). Essentially, there are two types of vent: (i) ones with one-way valves (like in the Bolin and Sam Chest Seals), and (ii) ones with laminar valves (like in the Russell and Hyfin Chest Seals). Their question was: do they both work the same?

What they found was that when the wound is oozing blood and air then seal design mattered. They found that the seals with one-way valves (specifically the SAM and Bolin) had unacceptably low success rates (25% and 0% respectively) because the build-up of blood either clogged the valve or detached the seal. By contrast, seals with laminar venting channels had much higher success rates – 100% for the Sentinel and Russell, and 67% for the Hyfin.

The Summary

So:

Sucking chest wounds are bad for your health.
Sealing the wound is good.
If the seal consistently allows for the outflow of accumulated air and blood, then that’s even better.

Therefore, now that we know all of this, one’s choice of chest seal is important. At CareFlight we use the Russell Chest Seal by Prometheus Medical (and no, we’re not paid to mention them we’re just sharing what we do). Why? Because it works – consistently. Both for us and in all the aforementioned trials.

Russell

The premise of this addition to the Collective is that you’re a first responder. That being the case, use an appropriate vented chest seal on a sucking chest wound.

However, you still need to recognise that the placement of the seal does not automatically qualify you for flowers and chocolates at each anniversary of the patient’s survival – you still need to monitor for and treat deterioration. Such deterioration is likely to include a tension pneumothorax for which the treatment is outside of the scope of most first responders (other than burping the wound).

If you are a more advanced provider then your treatments might include the performance of a needle thoracocentesis, or perhaps intubation with positive pressure ventilation and a thoracostomy (finger or tube).

In essence, know the signs and symptoms then master the treatments that are inside your scope of practice. (Or you could enrol in a course…such as CareFlight’s Pre-Hospital Trauma Course or even THREAT… OK that was pretty shameless.)

Meanwhile we’d love to hear:

What chest seal do you use?
Why?
How does it go?

Or you could just tell us what other things you think suck.

charles-deluvio-456804-unsplash — Could be the leafy green thing. Could be a person maybe.

Notes:

We’re not kidding about hearing back from you. Chip in. It only helps to hear other takes.

You could also consider sharing this around. Or even following along. The signup email thing is around here somewhere.

That image disparaging all things Kale (or kale) is off the Creative Commons-type site unsplash.com and comes via Charles Deluvio without any alterations.

Now, here are the articles for your own leisurely interrogation.

If you’re time poor and will only read one, make it this one by Littlejohn, L (2017). It’s “Treatment of Thoracic Trauma: Lessons from the Battlefield Adapted to all Austere Environments”.

Another great one (albeit somewhat longer) is by Kheirabadi, B; Terrazas, I; Miranda, N; Voelker, A; Arnaud, F; Klemcke, H; Butler, F; and Dubick, A (2017). It’s “Do vented chest seals differ in efficacy? An experimental evaluation using a swine hemopneumothorax model”.

An oldie but a goodie is this one by Kotora, J; Henao, J; Littlejohn, L; and Kircher, S (2013). It’s “Vented chest seals for prevention of tension pneumothorax in a communicating pneumothorax”.

To round it out, take a squiz at Arnaud, F; Maudlin-Jeronimo, E; Higgins, A; Kheirabadi, B; McCarron, R; Kennedy, D; and Housler, G (2016) titled “Adherence evaluation of vented chest seals in a swine skin model”.

Podcast

Podcast #4 – Another Side

November 1, 2017 careflightcollective 5 Comments

Straight back with another podcast and with the same guest, Dr Blair Munford.

This time Blair has a very different type of story to share.

Please have a listen and consider sharing. Or if you like the site consider signing up to get emails when posts hit.

Anyway, here’s the various ways to get the podcast.

Right click and choose save as to download the podcast. (That’s control-click if you’re on a trusty Mac.)

Of course you could just find the podcast over at iTunes here.

Or the rss feed is here.

justin-luebke-43531

There’s a chance that something about Blair’s story might make you want to help someone, somehow. If that’s the case either drop a message in the comments or email at careflightcollective@gmail.com and we’ll follow up.

In this episode all the music is by Broke for Free and available via Creative Commons at the Free Music Archive.

The image is by Justin Luebke and was uncovered at unsplash.com

Paediatrics

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

March 14, 2015 careflightcollective 6 Comments

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.

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.

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.

The Collective