The Hot Zone – Starter Points for Burns Anaesthesia

A recent review in the BJA on fluid management in burns patients is a trigger to consider some tips for managing the patient having burns debridement. By Dr Andrew Weatherall

Why would you do it? Why would you vary your usual practice with a pleasant surgeon(*), predictable procedures and a pleasant theatre environment just built for the pyjamas you change into each day when you pitch up?

Because anaesthesia for burns patients almost guarantees all of those usual conditions will be violated. Well, the surgeon will probably be fine but predictability predictably flies out the poky theatre window and the theatre environment is likely to reach “public transport in summer when the trains are all replaced by buses” level.

You do it partly because the patients turn up. Burns continue to happen and that isn’t going to change for as long as people like hot drinks, kids like helping in the kitchen and flames just look so cool. (Yes, let’s be honest. Fire looks amazing.) Even moving fitness indoors has created an entirely new and pretty terrible class of burn injuries thanks to the rotating belts of treadmills meeting curious little hands.

Management of burns patients can be extremely challenging and you can dig a very big pit in the middle of the operating room floor almost before you realise. And the surgical team may attempt to bury you alive in that pit with the dressings they are throwing everywhere which only makes things even less great.

I started thinking about this partly because it was prompted by work and also after reading a recent review in the BJA with some useful reminders of important things in fluid management and monitoring options. It covers a whole lot about required volumes but just as importantly the pros and cons of different choices. In particular it mounts a comprehensive case that colloids, particularly albumin, aren’t such a bad thing after all. At least in these patients.

The Main Game

Fluid choice is just a very small part of dealing with burns patients though. Most times you’re looking after a patient with burns the procedure will be small. That would be easy to get ready for. It’s the big debridement/grafting-type operations that can be particularly challenging when they get going a few days down the track after the burn. Set up for this and you’ll cope with those lower level cases easily.

So what’s the set-up? Well I’m glad you asked. Here are just a few thoughts about getting ready for that burns debridement.

1. Get the Story from the Surgical Team

It’s imperative to know what the surgeons are planning. Is today just dressings? Is it time for debridement? How much grafting and from where and to where? The surgeons will be happy to share this info, but like every other setting you might need to prompt the discussion to get the full story.

2. Acknowledge that Whatever the Surgical Team Says is Wrong

Not “Jar Jar Binks is the greatest character in the Star Wars Universe” wrong. More like their estimate is rarely on the mark. A variety of factors might play into this. In the early stages the assessment by people other than burns specialists can be not quite on the money. Then they start getting their treatment and days pass between occasions when the surgeons actually get to see how things are progressing. Burns are dynamic and what they anticipate when the dressings come off might be way off the mark. And once they do see it, it’s pretty rare for them to say “we should just do less and see how that turns out”.

So absolutely get the story. Ask how much they plan to debride. Get a percentage. Then double it.

owl-copy

Sometimes you have to assume the story from the surgeon matches the accuracy of the words on the page and legs on the owl seen here. Look at those legs. Just look at them.

3. There Will Be Blood

Burns surgery of this type is traditionally not that delicate. In preparing the burnt area for grafting they will cause more than a bit of bleeding in that hyperaemic patch. A burns surgeon once described to me the aim of traditional blade debridement as being to get down to the point where you see punctate bleeding.

Locally our surgeons now have access to a device called the VersaJet which effectively uses a repeated jet of water to act as a delicate scalpel blade. This allows them to go just a little less deep and hopefully produce less of the red stuff. Either way, little punctate bleeding is the most they’d aim for.  How bad could that be?

Well for each % total body surface area debrided (forget the donor bits), you need to think that the patient will lose around 4 mL/kg of their blood volume. Or perhaps it’s easier to think that if the patient has 20% of the burn debrided they will lose one blood volume. (I know at least one colleague who just uses the figure of 5% blood volume per % TBSA debrided which is probably a bit more direct for calculations. One of the reviews referenced below suggests 2.6-3.4% in adults per % TBSA debrided but I’d say allowing a little more is prudent).

However you calculate it, you need to have a plan for a transfusion which could become massive pretty quickly. This means more than just having the red stuff available and knowing you have other factors to manage any coagulopathy. It influences your choices around venous access, the fluid lines or devices you have ready to give the blood and some of the decisions around monitoring. Speaking of which …

4. Keeping in Touch With Things

Even if you sit down and think “which monitors could be hard to keep on” you can’t quite appreciate how difficult this can be. Things you can measure via the breathing circuit are fine. Pulse oximetry is a constant battle. ECG may be impossible to get happening with dots. In my joint we have an oesophageal ECG set-up which can at least provide a rhythm. Most of the time. Blood pressure? Well non-invasive can be hard if limbs are involved in the debridement or grafting and a low threshold for using invasive measurements makes sense anyway. But there’s a good chance that you’ll be having regular chats with the surgeon to re-establish a bit more monitoring to help you out.

5. Get Ready to Move

There’s another element of these anaesthetics which I find pretty unique. Movement. It is not just a case of repositioning for phases of the anaesthetic. Some of the dressings require the patient to be lifted, or held sitting upright to allow wrapping of the torso, or movement around the head and neck while wrapping is done there. A bit of anticipation is important here. How will you secure items like endotracheal tubes (wires, anyone)? How will you work around each other? How will you coordinate the necessary people to both do the lift and be free to provide the anaesthetic?

6. Heating Things Up

Did you see how many things we ticked off before we even got to thermal issues? Actually that’s arbitrary as the order could have been placed any which way and you’d still need to start temperature management early. Exposed patients having large parts of their surface area debrided plus cleaning that requires fluid and large infusions of volume can turn out to get cold.

So warm the room to just that little bit tropical and accept you might want to change later. Use an overhead heater and remember that it works better if the patient is close to it. Raise that bed when you can. Try and get a forced air warmer over a non-wet area whenever you can (you can turn a forced air warmer into an effective cooling device if you end up using it to help evaporate fluids pooling next to the patient). If you have a solid warming mattress get that out too. Warm those fluids. And perhaps most importantly agree on some limits. It’s worth reminding the surgeons that if the patient gets too cold you might have to just ask them to step away for a bit while you catch up. An agreed target beforehand can help. I get a little nervous at 34 degrees depending on where things are up to in the operation. We’ll at least have a chat at that point.

7. Aim for Pain Free

This is a massive topic all of its own. But it is worth noting the obvious. Analgesia for these patients is complex and needs to be comprehensive. Poor analgesia can really impact on the patient’s long-term psychological recovery. The initial injuries are painful. Some of the dressings are painful when they go on. The operations are painful and the nociceptive mix is broad. Super-imposed itch can really complicate the issue. The patients are also in for a long time and that creates all the issues that long-term complex analgesia is associated with.

So beyond using appropriately generous doses, straight opioids don’t seem a good answer for these bigger cases. Think multimodal and utilise agents with NMDA actions (methadone or ketamine being good examples). Add imple things like paracetamol. Consider non-steroidal agents. Consider other options such as α2 agonists, or agents that help with neuropathic elements. And importantly make some plans beyond now that will allow flexibility for later. If you’re not quite there, where will it escalate to next and who is keeping an eye on it? Getting the analgesia right is rewarding for you and makes such a big difference for the patient.

 

So that’s the broad look. Anaesthetising for big burns surgery is a heavy day at the office. It demands a bit of planning, a lot of attention and a heap of flexibility. But the toughest anaesthetics can provide the biggest rewards and when you get through the heat of the operating theatre with that safe, comfortable patient, there’s really nothing better you can do.

Except maybe go and change those scrubs. I’m not even joking. Did you forget how sweaty you were? You smell. Change right now. Go.

Please.

 

Notes:

(*) If you are an anaesthetist who does not work with pleasant surgeons then I am sorry if this was triggering for you. Also I really hope you stop that and go and find surgeons who are not shaved down bridge trolls with a tertiary education. Really, good luck.

That image comes from a book in the library and every time I read it to the kids I have to hold them a little closer, fearing that such a distortion of the natural order as that owl may actually exist.

This post doesn’t come close to covering the world of burns anaesthesia of course. There are all sorts of fascinating pathophysiological changes after the burn I haven’t even touched on. I highly recommend having a look at some of the following reviews to get a bit more insight or brush up on stuff you already know.

Here’s the BJA review:

Guilabert P, Usúa G, Martín N, et al. Fluid resuscitation management in patients with burns: an update. BJA. 2016;117:284-96. 

Here’s a pretty good review from 2009 specific to paediatric patients:

Fuzylov G, Fidkowski C. Anesthetic considerations for major burn injury in pediatric patients. Pediatr Anesth. 2009;19:202-11. 

This one is perhaps a little more designed around adults, but is very comprehensive:

Bittner EA, Shank E, Woodson L, et al. Acute and Perioperative Care of the Burn-Injured Patient. Anesthesiol. 2015;122:448-64.

Then there’s this one:

Bishop S, Maguire S. Anaesthesia and intensive care for major burns. Cont Ed Anaes Crit Care Pain. 2012;12:118-22.

 

Did you make it this far? Good on you for scrolling down. Why don’t you reward yourself by looking at this amazing demonstration of how silent an owl can be in flight? See, it’s not that I don’t like owls. Just that unnatural and freakish picture.

 

 

 

 

3 responses to “The Hot Zone – Starter Points for Burns Anaesthesia

  1. Pingback: The Hot Zone – Starter Points for Burns Anaesthesia — Songs or Stories | Prehospital and Retrieval Medicine - THE PHARM dedicated to the memory of Dr John Hinds·

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