Category Archives: Practical Things

The Red Line – Getting That Arterial Line

There are plenty of times in the land of retrieval (and in some prehospital settings) where you need a little bit more than the simple squeezy cuff gives you. An arterial line. Maybe we could share some tips that work for at least one person with the hope of encouraging people to share theirs. This post is from Dr Andrew Weatherall.

There are things in medicine that are more than a bit disconcerting. Clinical practice pretty regularly asks us to skate back and forth between degrees of uncertainty and deal with it. So you take your reassurance where you can and sometimes that is in the form of a red wiggly line – the arterial pressure waveform. Yes, I’m that sad.

XoMEoX
Look, here is the very evocative image that flickr threw my way when I searched for “red line” under Creative Commons. Think about it.

Given the problems associated with other monitoring methodologies in retrieval medicine having a more accurate option for providing haemodynamic information is invaluable. Add in the option for easy blood sampling and moving a critically ill patient is clearly made a lot more appealing with an arterial cannula in place than without it.

They can be a bit of a bugger to get in sometimes though. Particularly in the area I spend most of my time which is paediatric anaesthesia. Now I don’t have a bazillion answers as to how to make it sure it always hits the spot but there are a bunch of things I always do to try and increase my chances of success. Now these might be things for deploying in little people but lets face it, adults are just big kids. Pathetic, large, disintegrating kids. Anyway, in no particular order here’s a few:

1. Check them all

It’s pretty rare that you need to specifically place an arterial line in one chosen artery for prehospital or retrieval work. Not all pulses were created equal though so it’s worth taking a moment to feel all the candidates to measure them up. Choose the best one for that first shot.

2. Get the position right

Whichever one you choose, it’s worth getting the position at its best for that particular artery. At the wrist I think a lot of us have been shown the wrist extended position, and that is usually pretty useful. It’s worth exploring how extended you need that position though. Sometimes when you go to extreme you can distinctly feel the pulse get a little harder to feel. And while a roll under the hips can make a femoral line just that bit easier, it’s worth doing a before and after check. . The bigger point is that you don’t want to just choose the best pulse, choose the best position for that pulse.

3. Know your kit

This is sort of a good rule for lots of prehospital and retrieval work. You need to know your kit and choose it well. Or if you’re utilising something at the place you’re picking up the patient, make sure you understand it. Different cannulae meet up to to the needle component differently. If you’re planning to have a wire as a back-up to get in (assuming it’s not an inbuilt option) you might want to double check the wire will get through the cannula. Know what you’re wielding. Plus at the same time it’s worth remembering that a smaller cannula in the artery is a lot better than a bigger one you can’t feed in. Choose the cannula you’re sure will get in.

Red dots
This also came up when I searched for “red line”. Bit of a fail there. That’s not a red line, it’s a line of red dots. It’s even called “Red Dots”. What gives flickr?

4. The Wire Bit

While I’m there, a wire can obviously be a pretty good friend. I know plenty of people who prefer the technique where you transfix the artery, come back and feed the wire up once the blood is flowing back freely. Plus get a smaller cannula in (see above) and that wire becomes the tool to dilate up to a larger bore cannula.

5. Sit Down

I know this seems really minor and maybe you feel strongly that you’re only doing it right if you’re in a moving vehicle and the family cat you brought with you to comfort the owner is sinking its claws into the back of your neck or up your nostril or something. The thing is trying to not let the environment control you is part of the gig. When you sit down you can set up your ergonomics a whole lot better and position yourself to take away muscular strain and fatigue while you’re doing it. So if the space allows it, sit down and get comfortable.

6. Side to Side and Up and Down

Now that you’ve hopefully found a comfortable position, it’s worth really mapping out that artery. Maybe other people have more sensitive fingers than me but I generally find that placing a single finger on the pulse and trying to centre it in the middle of the pad of my fingertip helps me get a sense of where it is. I then use that same finger to feel up and down the artery and figure out its course so I can mark it on the skin. It actually doesn’t matter a huge amount if the mark is perfect as long as I can go back, feel and understand where I’m feeling the artery in relation to the obvious mark I’ve made. I do this every time to help construct a picture in my head of how it all lies, even before I get onto ….

7. Use an ultrasound

If it’s available, then probably just use it. The evidence says that you’re more likely to get it in without incident and it’s unlikely to be a slower endeavour. Using the ultrasound well still demands good patient and clinician positioning as well as a scout scan up and down the artery to understand its course and any surrounding stuff. Small ultrasounds are now good enough that you should be able to pick up the tip of the cannula all the way into the middle of the vessel (and spot when you’ve still got a little bit of tissue indenting at the wall). Just use it.

8. Short, sharp, flat

It makes pretty obvious sense to approach without too steep an angle (though sometimes you can pop through the skin better with that sort of angle). A flatter approach maximises your path in the vessel which maximises your chances of staying in there. When it comes to movements I find an approach with short, sharp advances more successful than a slow steady push. At least in kids sometimes the latter seems to allow that artery to squeeze out of the way (but I’m happy to be pulled up on that one).

9. Also use local

If the patient is awake of course. Why?  I think that’s actually an obvious one.

Marco Galasso
This one, also came up on the “red line” search but really it’s about the dog. So maybe if you want to get arterial lines in, think more about puppies?

10. Be ready for success

You’re probably going to be brilliant so be ready for that not surprised. Having those tapes and connections ready so you can focus on the bit after the cannula (particularly trying to maintain a clean and dry field so everything sticks and you don’t have a bunch of stuff to clean up) lets you get on with actually using the monitor.

 

So there is my meagre collection of practical bits and pieces. In the prehospital and retrieval space I can’t always guarantee that I can set myself up like I can in an operating theatre. When I make the effort though it turns out I usually don’t have to compromise that much. And that effort usually makes the whole thing go a little bit smoother.

It’s also not an exhaustive list. So if you’ve got a top tip then hit up that comments section. I could use a tip to be better next time I’ve got to step up to the red line.

 

Notes: 

The main reference to read for this one would be this Cochrane review looking at success rates for arterial cannulation in kids using ultrasound. The short version is yes, do that.

All the images here were from Creative Commons posts on flickr.com. The first is from XoMEoX, the second is from Håkan Dahlström and the third is from Marco Galasso.

 

 

 

 

I Wish I Knew Then What I Know Now: Simple Airway Management

This is a popular series and it’s not hard to see why. Greg Brown drops back in to talk about the airway device that is now his go to item. 

I clearly remember a time when the escalation of airway management in prehospital care resembled the fabled Underpants Gnomes from South Park and their three step plan to making a profit.

Back then, airway management looked something like this (and yes there were four steps, not three like in South Park):

  1. Patient’s own airway – bummer; that’s no fun for anyone.
  2. Oropharyngeal airway (aka the Guedel) – fun but not that inspiring.
  3. Endotracheal tube – break out the high fives, it’s a good day to be a medic.
  4. Needle cricothyroidotomy – if an ETT doesn’t do it, a 14 gauge cannula in the throat ought to fix it. Then there are the mutual backslaps.

Back in the day when I was new to military prehospital care (and at a time where not much was happening in the world) the focus seemed to be on big ticket items and not the purpose of the interventions. Indeed, it seemed to me that the drug of choice for any airway problem was plastic; and the bigger the problem, the smaller the dose.

What I know now is that the one’s choice of procedure must consider a whole lot more than just self-gratification. Airway problems are generally either an oxygenation or a ventilation issue, and the choice of procedure must take at least this into account. However, the purpose of this post on the Collective is not to discuss the differences between CICV and CICO (nor the relative advantages of DL vs VL) but simply to discuss basic airways.

Simple Is As Simple Does

There is no doubt that a patent airway that was issued to the patient at birth is best for the patient. Therefore, it goes without saying that anything that can be done by the treating professional to maintain a patent natural airway should be at least considered. I am not going to go into how best to clear an airway and position a patient as there are a myriad of reputable sources out there for you to conduct your own research but I will make two important points:

  1. In a perfect world the “ideal” position will align (and therefore open) the upper airway; seemingly minor changes in positioning can have significant detrimental impacts on airway potency (and vice versa); and,
  2. If you don’t know how to position a patient or provide manoeuvres then you might want to consider taking a step back and booking into a first aid course. Quite quickly. Like right this second. Just do it ….

Still here? Good then, on with the show.

Which means it’s time to introduce one of the heroes: a simple artificial airway. To Guedel or not to Guedel? For many years that has been the question, and the oropharyngeal airway (OPA) was definitely my plastic of choice. Simple to insert and effective – two of my favourite things in a medical device. But are they deserving of their historical gold medal for simple airway adjuncts? Well, maybe yes and maybe no.

You see when it comes to simple adjuncts I have become, over the years, a massive fan of the nasopharyngeal airway (NPA). I would argue that they are just as simple to use as their orally inserted cousins – the operator just needs to be trained in their use. And whilst there are pros and cons to all medical interventions in my mind the NPA has one big benefit over the OPA – when (if) the patient starts to rouse the NPA can stay in, a handy thing for those pesky patients whose level of consciousness ebbs and flows.

Over the last ten years the NPA has gained popularity amongst first responders with thanks to support from some international heavy hitters, and not before time. You see, the NPA was actually invented before the OPA – 38 years earlier, in fact, by Joseph Clover of the Royal College of Surgeons (he later became a founding member of the Royal College of Anaesthetists) in 1870. The first OPA was designed by…. wait for it… Frederic Hewitt in 1908. The first “Guedel” was not even invented by Arthur Guedel whose name is now synonymous with the device. He didn’t enter the scene until the 1930’s (but I will grant that he made huge improvements to Hewitt’s rudimentary designs).

However, it was not until 2002 and the widespread introduction of Tactical Combat Casualty Care (TCCC) in militaries worldwide that the NPA started gaining favour once more. With thanks to a push from the United States Department of Defense’s Special Operations Command, NPA’s started making their way into the individual first aid kits of soldiers, sailors and airmen employed in combat operations. Indeed, by 2008 every Australian serviceperson employed in combat roles carried an NPA in a pouch alongside appropriate haemorrhage control devices. NPA’s are now taught as part of C-TECC guidelines (the civilian version of TCCC) and are now commonly the first artificial airway device reached for by those employed in first responder roles worldwide.

Table

Are there risks associated with the of an NPA? Well, this is medicine, isn’t it? Of course there are risks. The big one that everybody immediately jumps to is in the patient with suspected basal skull fracture (or a fracture of the cranial vault). The risk in inserting an NPA here is that the tube may indeed enter the cranial cavity instead of heading into the nasopharynx. But a review of the literature reveals only two cases where this occurred thus making it a rather extreme reason to be afraid of using an NPA. (Note: that same review of the literature also revealed an article advocating the use of nasopharyngeal airways in the treatment of watery diarrhoea…. Four words: single use only please!)

Putting It To Work

So how do you utilise an NPA (and I’m talking about as an airway device, not in treating diarrhoea of any consistency)? Well firstly, size matters. I am sure that at some point you, like me, have taught various methods. The first common method is to look at the diameter of the patient’s pinky finger – in theory, this is the same diameter of the nares (nasal openings). Therefore the NPA of choice should be the diameter of the patient’s pinky. Yes?

Alternately, the second common method of sizing pertains to length – in theory the distance from the nostril of choice to the tragus (that flap at the front of the ear where it meets the cheek) is the same as from the tip of the nose to the upper pharynx. Yes?

Well, research by Roberts et al in the EMJ found that a combination of the two methods is required to get reach NPA nirvana and that in fact the patient’s height was a better determinant of requisite NPA size. They used data from MRI scans to determine that, all things considered, the law averages reigned supreme. Average height male? Size 7.0mm Portex NPA. Average sized female? Size 6.0mm NPA. Or, you could await the rollout of the MRI App on your smartphone of choice…

Once you have selected the correct size NPA you simply pick the largest nostril, lubricate the outside of the NPA (the patient’s saliva is usually sufficient) and insert whilst aiming for the patient’s ear (the same side as the nostril you are using). By aiming for the ear you are pushing backwards, not upwards, thus reducing the risk of the NPA entering the cranial vault in that patient with a suspected basal skill fracture. For this reason the presence of a suspected basal skull fracture has relegated to the status of relative contraindication (no longer an absolute contraindication). If any significant resistance to insertion is felt then the attempt should be aborted and the other nostril attempted.

Be sure to consider how you will secure the NPA. Certain members of society have naturally wider nares and I’ve seen them inhale their NPA. Placing a large safety pin through the shaft of NPA just below the flange decreases the chances of this happening, but in most patients I’ve treated the safety pin has not been necessary.

 

So there you have it – another thing that I know now that I wish I knew then is that the NPA is not an evil device guaranteed to lead any patient who has ever experienced a blow to the head on a one way trip to the morgue. Rather, the NPA is now my simple airway of choice, an intervention that I have used countless times both on battlefields and in emergency departments, and is the only airway device that I carry on every single job. Oh, and it also has some purpose in treating patients with watery diarrhoea…apparently.

 

Notes:

Remember if you like things on this site there’s a box somewhere where you can throw your email address so you get a regular email when a new post hits.

Want to know about how your choices of airway adjuncts can affect ventilation? Then go here.

Interested in reading more about the facts and myths of NPA’s? Try this.

Here’s a cool little video about airway manoeuvres and simple adjuncts from that good crew at Life in the Fast Lane.

And a previous post that included the use of NPA’s in the tactical environment can be found here.

 

I Wish I Knew Then What I Know Now (Edition 2 – Packs)

Continuing a theme started with a practical post on direct and indirect pressure for haemorrhage control, Greg Brown (Education Manager amongst other things) discusses the things he’s learned about how to figure out what you need in a kit. 

I remember the first time as a young Nursing Officer in the Australian Army I went on exercise (that’d be “manoeuvres” for you Americans, and “war games” for those that watch too many movies) and had to pack a medical kit. Not knowing what was required for the job (and not asking either) I had earlier visited the field pharmacy with a request that was essentially “one of everything you have, please Ma’am”.

The result? I spent three days being cold, wet, hungry and slow – the sheer size and weight of my medical kit meant that I had not enough room for “luxuries” such as a sleeping bag, raincoat or enough food.

Now what?

So, what has changed over the years? Well, I’d like to think that a lot has changed. Firstly, I now have the experience to know that if I cannot do my job (because of issues pertaining to cold / heat / hunger / thirst / ability to keep up etc) then I am a liability and not an asset. I have also learned that the greatest skill ANY prehospital care provider can possess is the ability to improvise. And finally, I’ve learned that big ticket “Hollywood” style medicine does not keep people alive but that, as a popular Australian breakfast cereal advertisement from the late 1980’s stated so eloquently, “the simple things in life are often the best”.

It is important to realise from the outset that there are arguably more variables in life when it comes to medical kits than there are medical conditions that need treating. Okay, that is a bit of an exaggeration, but hear me out. When creating a medical kit the individual must ask themselves a series of five questions that will guide the size, contents and capability of their kit.

Question 1: Who will be using the kit?

If the answer is simply yourself, then you can afford to consider taking items that are your favourite but not necessarily everybody else’s preferred option (caveat: they still need to be evidence based and supported by your clinical practice guidelines / protocols). An example is in regards to airways: you might be an avid supporter of the iGel whereas I sit firmly in the LMA Supreme camp whilst there also exist individuals who like the King-LT. One could argue that they all do similar things and possess commonalities (e.g. blind insertion, semi-secure airway etc) yet they each require necessary knowledge, skill and attitudes in order to make them work. The solution, in this case, is standardisation – not three separate but similar airway devices.

Question 2: What is the kit expected to be capable of doing?

Within CareFlight we have many different lines of operation; for ease lets call them Sydney, Darwin, International and Off-Shore. So, take our Sydney operation – CareFlight Rapid Response Helicopter (CRRH). CRRH works as part of a wider retrieval network to service the Sydney basin. The majority of its taskings are to traumas and near drownings, so its kit reflects this. CRRH is unlikely to be tasked to a ketoacidotic haemophiliac with sepsis on a background of COPD. Why? It services the Sydney basin where there are also around 50 ambulance stations, each staffed with well trained, well equipped and well-motivated paramedics who are standing by to deliver the patient to one of a dozen equally well staffed / trained / equipped / motivated hospitals, that are available 24/7. If CRRH is treating and transporting this patient then it is because they’ve been ejected off of their motorbike whilst completing stunts at the local motocross track (again, perhaps a slight exaggeration for this particular patient), so the activation is to a trauma. CRRH’s kit must reflect this, just as the Darwin, International and Off-Shore kits must (and do) reflect their demographics.

The same goes for medical kits of a more “tactical” nature. If your tactical kit (the one you wear on your rig when conducting a deliberate action / breach / clearance etc, or every day because you are clever and “that’s how you roll”) contains a laryngoscope then I’d respectfully suggest that you’ve got it all wrong. Interventions in this environment need to be high yield and rapidly applied whilst allowing for the maintenance of situational awareness. If you are head down / bum up intubating, you are not accounting for your own safety. Besides, is the expectation now that this patient will self-ventilate? Or does your tactical kit also contain a self-inflating bag or mechanical ventilator?

Question 3: How long does this kit need to last? 

This is a question of stock holdings. When I think back to that first Army exercise in a medical role of mine I now ask myself “it was only three days long, so why did I need seven days’ supply of three different oral antibiotics – especially when we were within two hours walk of a field hospital?” My stock holdings were all wrong. Chatting with many others over the years (both military and civilian) I have found that this can be a common theme amongst pre-hospital care providers.

If some is good, more must be better, right? Wrong – more just means bigger, heavier and slower. Besides, if you brought it – you’re carrying it.

But what if one fails, won’t I need a second / third / fourth? To this I offer that if your plans are built around multiple failures in equipment then it is time to revisit your equipment list and look for alternatives that are more robust and reliable.

An important consideration when assessing how long your kit needs to last is: what is your mission? If your mission is to conduct humanitarian assistance in the wake of a natural disaster for a period of seven days then you are going to need a LOT of stuff – trust me, having deployed to a few natural disasters in my time you will require a very robust supply chain. But if your mission is to treat and transport one victim of that natural disaster at a time with a resupply between each mission then you don’t need that much gear. Besides, generally speaking the less you carry the faster (and further) you can travel.

Stock holdings are a balancing act. It is reasonable to build some redundancy into your medical kits (ever had that one vial of morphine in your kit smash when someone decided to use your kit as a stepladder?) but it must be balanced with the knowledge that if you brought it, you’re carrying it.

Question 4: Is the kit a “stand alone” or designed to be augmented?

Capability should be viewed in terms of three things:

  1. people;
  2. equipment; and
  3. the ability to effectively combine the first two points.

I learned a long time ago that I was never going to be the only person in a group with medical training. Every “operator” (e.g. police officer, fire fighter, soldier, aircrew member, emergency service volunteer etc) has basic first aid training (and sometimes much more) and many will carry their own supply of essential items (i.e. arterial tourniquets, bandages, gloves etc). In situations where medical attention is required, medical personnel need to utilise the capabilities provided by others.

It is always worth considering this concept of capability when forming your plan; planning to combine medical kits in order to create improved capability is a useful concept. Most military and paramilitary units do just this; as an example, the Australian Army’s Parachute Surgical Team (PST; now superseded) built its equipment plans around the “what ifs” of war and how to ensure enough capability without carrying a whole hospital worth of equipment.

What do I mean by the “what ifs”? Well, I’m glad I asked myself this question.

What if the plane carrying the equipment got shot down before we could drop the stores? Well, each member of the PST parachuted with a medical kit that, when combined with those that others carried, formed an interim resuscitation and surgical suite. What if a paratrooper and his / her kit went missing? Well, there were just enough team members to space out on separate aircraft to create two identical suites. What if a paratrooper required more than first aid on the drop zone or during the advance? Well, each kit also contained the stores statistically required to treat a battle casualty.

Each kit creates a capability; but when combined they can provide so much more. This is an important concept to keep in mind when designing your medical kit.

power-rangers
It’s a bit like the Mighty Morphin Power Rangers. Individually they don’t necessarily get the job done but when combined they offer … Spandex. And also getting things done.

Question 5: Can you actually carry it? 

Size matters. I’ve said it a few times already, but size really does matter – if you brought it, you’re carrying it.

For a medical kit to be effective it needs to be capable of getting to and travelling with the patient. Therefore, if it is so big and cumbersome (because you packed one of everything…and some redundancy) that you cannot get to the patient then you need to ask yourself “what is the point?”.

Now, I will freely acknowledge that different sizes are required for different tasks – in fact, I have four different kits in my personal armoury for four different purposes. Similarly, CareFlight has different sized kits for different tasks within its separate lines of operation.

So some things to consider include:

  1. Is this kit staying in a vehicle (if so, what type of vehicle?) or does it need to be portable by an individual?
  2. If it is portable, what else is that person carrying (e.g. a tactical kit will likely sit between other pouches / holsters on a belt or chest rig whereas a bigger kit may come with shoulder straps or need to fit inside another pack)?
  3. When packing it, how many pouches will you need to open in order to perform one intervention? (Note: the answer should be one; if your IV cannula, sterile wipe, venous tourniquet, securing tapes, bung, giving set and fluids are not together then you’ve got it wrong.)
kits
OK I may have a bit of a kit fetish but each one has a specific purpose in life. Beyond just making me happy even.

Summary

So there you have it. Added to the list of “things I know now that I wish I knew then” is medical kits. I now start with an analysis of the mission, draw out the likely tasks, consider the need for redundancy, look at what else I need to carry and consider the overall capability. What I don’t do is request “one of everything please, Ma’am”.

 

Notes:

This one is much more of a recount of personal experience so there aren’t a heap of links to send you to. It would be great if people could give examples of how they think about their kits and what they carry though. It’s a good bet there are clever people out there who would point out things that haven’t come up here.

Oh, and don’t forget if you like the stuff on here there should be a spot somewhere on the page that lets you follow along so you’ll get an email when a post goes up.