BTK Burn Resuscitation-gettings things started

Welcome to another episode of Behind the Knife podcast, clinical challenges and burn surgery. My name is Jamie O and I'm a current burn trauma and critical care fellow at Harborview Medical Center in Seattle. And I'm Alex. I'm the other burn and critical care fellow here at Harborview Medical Center.

My name is Tom Tam. I work at Harborview Medical Center. And I'm Rob Cartato. I'm a burn surgeon in Toronto, Canada at the Ross Tilley Burn Center. Julie Rizzo, Lieutenant Colonel, United States Army, burn and trauma surgeon at Brook Army Medical Center. Julie, it looks like you might be driving. Oh, absolutely.

I'm multitasking, Tam. Okay, so today we'll be discussing burn resuscitation and really focusing on some of the challenges in our burn centers. Okay. We'll start off with a case. So a 45 year old male sustains a 60 percent TBSA burn while incinerating garbage with gasoline. He's brought to a peripheral hospital staffed by a single emergency medicine physician 850 miles from

the nearest burn center.

His burn is of mixed depth, but clearly full thickness to both legs and arms. After speaking to the ER physician, the patient will be transferred to your burn facility by fixed wing. So we're going to unravel this case with some panel questions and discuss some of the nuances of the care of the patient.

Alex, do you want to start with a first question? Yeah, I think through the big topic that comes up here when you have a patient who's far from your burn center and something that here in Seattle we face. So just to start us off, Dr. Pham, I wonder if you can just touch on some of the challenges you face when accepting a patient in transport.

Yeah, happy to answer that. You guys. This is a common situation for us as we transfer patients in from a long distance sometimes. So from our own state, from adjoining states, and sometimes even from Alaska where we fly over Canada to get to us in Seattle. The first issue is the invention of hypothermia.

I would advise this physician who's calling us. To quickly estimate the injury total body surface area or

TBSA by adding up the second and third degree areas and not the first degree, which is a mistake that people make sometimes in adding up TBSA. Then they should quickly cover the patient with a warm blanket or other insulating device, typically used during transfer.

Remember that small helicopters and some fixed wing planes ambient temperatures. In other words, the patient is essentially traveling in a cargo bay. On arrival, external warming devices work really well, and a warm blanket can be a good, productive device, meaning that contact with the patient will help warm them up.

A forced air blanket, such as a bear hugger, will warm the patient by convection. We also use radiant heat warmers when they are up in the unit, known as heat shields. And finally, intravascular heating catheters can help in more severe cases. Hypothermic patients are at greater risk for both infectious and non infectious complications.

And for every degree below 30, 60 degrees Celsius, mortality goes up by at least 5%. So I think that's the first thing that I want to make sure that outside

physician understand. Dr. Cortado, is there any unique challenges you face in Canada from that perspective? Yeah, we have sometimes very similar long transport times from northern Ontario.

You know, looking at, you know, the things that really give me the most trouble and which give patients the most trouble is how do you sedate and keep these patients comfortable? And I find that certain anxiolytics and analgesic medications, many of them do have hemodynamic effects, and that really can complicate the whole fluid resuscitation approach.

And agents like Propofol, for example frequently get started out in the periphery, and before you know it, the patients are hypotensive. And if they're a little behind in fluid, the next thing you know, they're on vasopressors. We get these patients from long distances where this has happened and so to answer your question about the big challenges that I face with these long transports, that's a big one.

Are there specific fluid volumes you recommend that emergency medicine

facilities run based on their estimate of TBSA? My own approach is I use that rule of tens. So 100 mils per 10 percent of the body burned. And then if they're over 80 kilos, another a hundred mils per hour for every 10 kilos over 80, but I'd be interested to hear what the other panelists do.

Yeah. What's the adoption 10 in Canada. That's like a really interesting news for me. Yeah, I wouldn't say it's widespread. It's something that I do personally when I get a referral, if I'm on call. I'm not sure all practitioners do that. They may just make a calculation based on modified Brooke or Parkland, depending on personal preference.

I really find that my biggest worry second to maybe the sedation effects and the hemodynamics is excessive fluid. And I find that that rule of tens works really well in sort of limiting the egregious volumes that the patients sometimes arrive with. Well, so as per usual, Dr. Cortado steals my thunder.

Since the rule of ten came

from the Army, I'm still claiming that. Obviously, I'm a big proponent of the rule of ten. And one of the biggest reasons that we've remained a strong proponent of the rule of ten, especially for the civilian burn transfers that we get, And the military casualties when the war was at its peak is the gross overestimation that burns are commonly diagnosed by outside providers.

We used to always joke at the burn center, it was the Rizzo rule of threes. And if they reported that the patient was anywhere between 20 and 80 percent burned, they were probably off by a factor of three. So if they said 30%, the patient showed up at 10%. And so by erring on the side of the rule of tens, it's just a little bit over 2 mL per kg per TBSA, which is on the lower end of a starting resuscitation volume.

But it makes up for the fact that if their burns are overestimated, because, Tam, like you said, they commonly will include first degree burns when they're not supposed to, this results in avoidance of excess fluid

in the early pre burn center phase. Yeah, you guys, that was a really important point. You can't really fill up the tank the first day.

You may try, but you may over resuscitate the patient in the process. Don't try to fill up the tank, otherwise you will get too much into the interstitial space. At our hospital, we use the ABLS formula of the time before you know your TBSA. So we use that 500 mL per hour blockaded ringless in adults. If it looks like a big bird, it's simple, it avoids over resuscitation, and for common birds we see, it's not far from a reasonable place to start.

But once you need ED, and if an injury TBSA is calculated, Then we would use something like three mils per kilogram per TBSA, estimate over 24 hours. Somewhere between Brooke and Parkland, because in between two centers in Texas, we didn't want to make anybody upset. So in Seattle, we kind of like to be in between like that.

It's very Canadian of you, Dr. Pham. That just means you're always making one center

upset while pleasing the other. Do you recommend that medics are titrating fluid volumes to urine output, or are they left at a steady state? That's Yeah, for sure. And a long transport. So anytime we get a call from a place that we anticipate the transport to be an hour plus, often you have to go up in case the UN app is not adequate.

Rob brought a new point about the tendency to use pressers. Can you elaborate for us? We did a study looking at vasopressor use in acute burn resuscitation. We were interested in patients who required vasopressors in the first 24 hours. And it surprised us because the variables we thought would contribute things like having a really big burn or being on very large amounts of opioid infusions or other anxiolytics.

had no relationship, and the only factor that seemed to predict the need for vasopressors was advanced age. And that may just reflect an elderly

person's cardiovascular responsiveness and ability to vasoconstrict and maintain cardiac output. So that was an interesting finding. That may just be sort of a relative vasoplegia that we see in older patients and also diminished cardiac function in older patients.

That's the group that just can't respond. You're giving fluid, you're trying to expand the intravascular space, and it's not working. I found another one from Iowa as well. So between the two papers, the incidence of using vasopressors while in the burn unit is somewhere between 20 and 30 percent, which is not insignificant.

Another place where we found a recommendation for pressures is in the joint trauma system practice guideline for burn. I think it's just a lot safer to do it in the burn unit when we know that volume support is a priority and we have a well monitored environment as opposed to be on pre hospital transport.

Dr. Rizzo, I was wondering if you could comment from a military perspective, any unique challenges that you face for long distance transport of patients?

Yes, absolutely. To speak to Dr. Pham's point from the JTS guideline, an updated version will be coming out, but it does still contain vasopressors as adjuncts for blood pressure maintenance in patients who are felt to be adequately resuscitated and not bleeding.

In terms of being able to stop the amount of fluids a patient with a large burn may need over an extended period of time. And if you did run the risk of running out of fluid, then what were you going to do? And the answer was vasopressors. We're big fans of vasopressin first line. I think in burn resuscitation, it largely functions as a hormone replacement, acutely.

It is just done very well for even our young burn patients with big burns. For transport for the military, very similar to a lot of the civilian challenges, hypothermia. We have a big warming blanket that is made for all military casualties. I tell every burn flight team and every combat flight paramedic that's actually good enough for your hemorrhaging trauma

patient with an open belly.

It's not going to even come close to keeping a burn patient warm. And so you just have to get creative. I always say burn patients are like babies, they lose heat out the top of their head, whether it's burned or not. So one of the earliest interventions is a nice warm blanket or a forced air device around their head, and that seems to actually warm their core pretty fast.

We always have to think about because military planes are never that nice about hearing protection and about eye protection for these patients. And so that's something often overlooked as you're worrying about all of the other things that scare you on a long transport. Do I have enough oxygen if this patient requires 100 percent FiO2 for a prolonged period of time at altitude?

Having enough fluid and so little things like Eye and Ear Pro. You got to have it for yourself. Mine will make sure you bring an extra sip or two for the patient. Dr. Rizzo, I have a question. When you're at altitude in a pressurized cabin, what happens in the intra

abdominal compartment? Like, any gas there should expand and raise pressures, and does that interfere with a burn resuscitation where you might be worried about rising intra abdominal pressures?

Yes, sir. Absolutely. We actually had a burn that we transported from Korea, and we'd gotten to it delayed. And he was already having mildly elevated intra abdominal pressures. And when we got to altitude, not only did he become profoundly hypoxic, but we did have increasing peak pressures on the vent. And we were forced to aggressively diurese him, and then try to maintain him as best we could with vasoactive medication to get as much fluid off of him.

Because there was other than paralytics, which are almost universally used on some of these long transports over bumpy air. You always want to fly over the Atlantic. You never want to fly over the Pacific when you want to talk about rough air. Not like anybody's looking at me to do a laparotomy on a KC 135 refueling jet.

It's really all we could

offer for him. And so we have experienced that in some of our thinner patients. Thin, muscular marines where they just don't have that give, trying to expand against their six pack abs. That's something that we have seen at altitude. So, in this specific patient, we just talked about the nuances of transport.

Once they've arrived at your center and just to review 60 percent TBSA and let's say 70 kilogram male, what guidance do you have or what are your practices at starting resuscitation once they've arrived at your center? So as I mentioned, for transport, I recommend rule of tens, but once they arrive.

Alex referred to this being a good Canadian. I make a compromise between Modified Brook at 2 and Parkland at 4 mils per kilo per percent, and I kind of ballpark it around 3 mil per kilo per percent burn as my starting number. Although I will say, after we did our practice guidelines, I've tended to move a little bit closer

to 2.

That's how I would start it. And then, well, we'll talk about albumin shortly. There's a role I think for albumin in this case, just depends on how soon you get the patient. Can you explain why you guys landed at closer to two rather than three or four? Well, that came from the practice guideline and there was moderate level evidence that starting at two ends up leading to less fluid overall.

And that one of those studies came out of the military. We felt that it's a safe recommendation. It's also what's recommended in ABLS now. Yeah, at our hospital, we would start at three. And that's just because we still want to be middle of the road kind of people, I suppose. Sometimes when the patient gets to us, Yeah.

They have either got a lot of fluid or very little. There is a natural desire to fix what was done before. Remember, I think you pick a place to start and you try to stick with it for an hour. See what the results are. Adjust the fluid rate based on the patient's condition.

The common thing I've seen, especially after you've had a long distance transport, is that a patient's physiology switched to the maintenance of intravascular volume at the expense of the periphery.

And then they meet a bone surgeon who really cares about their skin, who disrupt the patient, do an hour of wound care, maybe improve on central access, do some escharotomies. All that takes a while. You also give them some vasodilating meds, such as pain meds and sedation for your procedures. That's And then you redistribute the blood flow to the periphery when you do that.

And I've seen so many times that the patient's urine output and sometimes even blood pressure crashes on you. And so you've reversed their physiology because you care about the skin, about warming up the patients. And so don't expect the first few hours are going to be smooth. Even if you get a really good sign out and great pre hospital care.

Do you guys do anything differently, Dr. Russo? We hold fast with the rule of tens. We're usually able to get the patient up into the burn center. Fully disrobe with bedside wound

assessment to get our initial TVSA. We're utilizers of the burn navigator clinical decision support tool. And then that helps us guide our hourly resuscitation volume.

I wonder if you could each comment on axis type and whether everybody needs a central line. Something that often comes up, whether we can resuscitate patients with peripheral axis and whether they need central venous axis. I think it depends obviously on the extent of the burn. More often than not, patients are on multiple medications and infusions and you just need that additional access that a triple lumen central catheter provides.

So almost always we end up putting one in. And typically also with an arterial line for monitoring, I would say for a 60 percent burn, meaning that you don't have as many sites as you used to. It's fine for the pre hospital providers to get an IBN or an IO, wherever they can. But once you're in the unit and you want something secure at last that has good high function, including

meds, as Rob mentioned, a central line for 60 percent burn, which is what this case is about is more often necessary.

Up to like 30 40%, I will try to do peripheral IVs often, but once you get above that 50 percent threshold, it's probably not worth it to do that. You know, in the general literature, we talk a lot about the differences between a femoral, subclavian, and IJ. Can you explain what else goes into the nuances of placement and site location for your central line and burn patients?

For me, it is always dictated by where the burns are located. So my go to sites are typically the femoral and then the IJ second. Subclavians probably are the safest from an infection standpoint, but my worry is that if we drop a lung and we've got burn over the area and have to put a chest tube through a burn, that can be a real problem.

So we typically, at our center, avoid a subclavian early on, and we'll go femoral route almost always or sometimes

an IJ, but that's just our local practice pattern. So we get our lines in wherever we can. We prefer non burn areas. Because they can last a little bit longer, but we don't have a true preference as to which site on the first day.

Usually we try to get our lines to come out and find an alternative site within a week. I'll add too that, you know, one of the other unique challenges is that a lot of our burn topical agents make it difficult for dressings to stay on. So making sure that your suture is well placed. In addition, sometimes the nurses will use a piece of Meplex AG instead of a typical central line dressing.

That seems to work well. So some of the things you don't think about until you're in the situation yourself. Dr. Rizzo, do you have anything else to add? Largely agree with Dr. Pham and Dr. Cartado. Femorals are usual go to. If the subclavian isn't burned, I'm a big fan of it more for maximal resident benefit in that I have so many anesthesia residents that rotate with us that never get to do

subclavians.

And We fortunately don't drop that many lungs, but it's really just the complexity of the resuscitation that necessitates it. You know, even with good IV access, you know, big 16, 14 gauges, there's just so much going on in a 60 percenter. It just facilitates the care. And then an A line is invaluable to me.

I always have a hard time when you have someone with a non invasive blood pressure cuff and an invasive arterial line. And they want to believe the non invasive because they like the number better. And I'm like, but this one's in the vessel. Why don't we believe the pressure in the vessel? And so that's something that I advocate strongly for as well.

Our practice is to change out our central lines every five days. That was based on work done by Kevin Chung and our burn unit as the optimal time to change. And our arterial lines, we used to also change at five days. But we have now demonstrated such a low, almost nil infection rate that they're now kept until they are no longer

functioning.

Along those same lines, when we're resuscitating a patient, what are your end points and targets? Wondering if each of you could comment on, are there any adjuncts to urine output that you think are of benefit? I know there's been a long discussion and review of the literature regarding PA catheters and burn resuscitation.

Looks like the data does not support their use, but I'm just wondering, is there anything else that you guys use? We rely, obviously, as you've just said, heavily on the urinary output, but also trends in the lactate and the base deficit, so we like to see those improving. I think of the other modalities, though, like pulse pressure variation.

If you look through all the literature, that is probably one of the best ones to identify the patient that is on that low end of the curve that might be volume responsive. But again, you have to do that carefully under controlled conditions, ideally with a calibrated monitor. And where you're using slightly larger tidal volumes, well relaxed, sedated.

If you don't do it really accurately, you

get misinformation. And then the other one that I think is helpful is a quick ultrasound, just looking for IVC filling. That's kind of my personal take on it. Yeah, back to what we were talking about before, the tank cannot be filled, the vessels are so leaky that you can't really expect to fill it, have enough volume so blood flow can go to an end organ like a kidney, and then this will produce the minimum desired urine output.

In Alzheimer's and many others, we would accept a urine output of 30 to 50 mL an hour for an adult. And beyond that, the tools that we talked about, some of them can help a little bit, but they haven't been validated. And if you find that a patient has a low volume and needs to be resuscitated more, I would urge people to avoid the temptation to fill the tank.

And prior research has indicated that when you try to fill the tank in a bone patient, you just over resuscitate them. So I'm going to be the young kid on the block and say I love technology. One of the first instruments that I bought for the burn flight team was the butterfly

ultrasound. I loved using it as just an adjunct guide in burn recess, IVC diameter, quick echo to see hearts filling.

My gold standard as everyone's is, is to have urine output goals. I try to teach to be very strict on a goal. I don't like to shoot for 30 to 50. I like to say, pick a number and be committed to it. If it's 30, it's 30. If it's 50, it's 50. Especially the residents because they'll talk themselves in and out of, oh, well, this 50 was good enough last hour, but 50 is not good enough this hour.

And I just want them to remain consistent about the elderly patients. I do like to use a Vigileo or an EV1000 on their arterial line. I think that identifies some elderly patients that may have that vasoplegia and that poor cardiovascular physiologic reserve. And if they're already on pressers, it may guide my presser choice.

So if it's someone with cardiac index of 1. 5,

now I know why I'm struggling so much. It's because I'm filling his pump, but his pump don't work so good. Almost universally with patients that can keep a heart rate lower than 140 and in a regular rhythm, I find the stroke volume variation to strongly correlate with urine output and responsiveness to fluid and correction of abnormalities and lactate and base deficit and resolution of hemo concentration.

And so if you give me the toys, I know the literature doesn't support it. And we, when we wrote our CPG and. I begrudgingly agreed to it because the literature didn't support it, but I will tell you that if you give it to me, I will use it in my practice. That's why we have podcasts. You know, people can listen to the variation in practice and preferences and it's not like reviewing a bunch of articles and then having to stick to a middle of the road answer.

Yeah, this is way more fun. Do you mind explaining to our listeners what FlowTrack is and what measurements you get, just in case they're not familiar? Yeah,

so the FlowTrack, known as the EV1000 or the Vigileo, depending on what brand you buy, gives measurements from cardiac index and output. Obviously, it's an indirect measurement, just like the SWAN is an indirect thermodilution measurement.

You can also get your vascular resistances in both your pulmonary and your systemic circulation. I will tell you that unless you have someone with like profound right heart strain, usually from a pre existing disease or a massive PE, the PVR has not really proven as helpful. The SVR will kind of give you an idea of the patient who really is peripherally vasoconstricted because, as we said earlier, you know, we're aiming to restore the intravascular volume at the compromise of the periphery and then you get to a burn surgeon and we're like, hey, we care about the skin.

I have seen changes in real time in the SVR when we've done these escharotomies and given a bunch of peripherally vasodilating meds and you've watched the SVR plummet, either in real time or just prior to watching the actual systemic blood pressure

plummet. And so I've always found that to be helpful.

You also get stroke volume variation, which you can correlate with your heart rate variation or your pulse pressure variation by looking at your routine monitor. So the, those are the main parameters that we have up on the screen during a recess. Do you use that for all of your patients when available?

There's definitely limitations. If the patient is persistently tachycardic, usually 140s or greater, the numbers are very shoddy. It's gotta be an ALINE with a good wave form that's gonna give you good data. So if you have a very positional ALINE or a very wiggly patient, it can be not as helpful, but they do have to be in a regular rhythm.

So if you got someone sitting there and could be 70, it could be 110, but they're in AFib, you're not gonna get reliable measurements. I like to reserve it for a recess that I'm finding to be difficult. We say they're not following the book. I also just like to use it when I have the opportunity to show the residents and how they can use it in their practice because outside of the cardiac ICU at my

hospital, the EV1000 is not widely used.

If nothing else, when the resident has to sit there and think through, well, what does stroke volume variation mean? Like physiologically, like make them understand that. And then they see the number and they say, okay, Dr. Rizzo said, make it go from double digits to single digits. And that means they're responding to volume.

Well, why would that be? Why do I want less variation? And so I find it as a good teaching tool to kind of like bring back the physiological principles of how this heart and blood system works. I have a question for Dr. Rizzo then, so let's say you see somebody with a stroke volume variation, double digits as you say, what do you do?

Do you turn up the rate? Do you give a bolus? How do you manage that? So, I have been trained in the military that boluses are bad, and so we don't give boluses. As you do know, Dr. Cartato, I am a big albumin fan. And so if I haven't had the excuse to start albumin yet at the 6, 8, 12 hour point, I do like to start that.

And

then again, it's patience is key. So I will go up on the rate. I'll look for other things that I can potentially correct to make sure that they're utilizing the fluid, you know, appropriately. Over the span of hours, you want to see that number getting better. You don't want to get better immediately because you probably just gave them too much fluid too fast.

Yeah, I think you hit a really important point there, Julie, about not bolusing. That's the tendency I'm afraid of. There's too much tendency to bolus. And I think even the trauma community is trying to come around to some of that more easy does it titration compared to just trying to fix everything all at once.

And I think the only other point I would bring up that I feel like the EV1000 or the FlowTrack has offered the opportunity is to make people more comfortable with down titrating. Like everyone's ready to go up on the rate. They're burned. They're really burned. You know, they need fluids that's driven into everybody's head.

But to say, Hey, look, they're getting better. In the last four hours, their SVV is gone from 15 to 10. We're making strides. And they're

consistently making 50 cc's a year in an hour and I only wanted 30. Let's make us be more willing to say, Hey, maybe we can back off a little. And I think anything that encourages the inexperienced provider caring for a burn patient to be comfortable with down titrating is a bonus.

I think that's the biggest hesitancy in non experienced providers is I'll go up, up, up, up, up, but I'm starting to be afraid to come back down. You're almost afraid you're doing too well. That concludes part one of our burn resuscitation episode. In this episode, we reviewed the challenges that come up when patients are transferred, particularly from long distances to a burn center.

Remember to focus on keeping the patient warm by removing any wet clothing, using warm blankets or forced air devices. Start resuscitation fluids at an appropriate rate using the rule of tens. the modified brook or parkin formula, or the ABLS formula. Adjust these

fluids once they arrive at your center based on the patient's condition and urine output.

Consider other endpoints for resuscitation, including pulse pressure variation, an ultrasound for IVC filling, and the flow track to help give more information if available. In the upcoming part two episode for burn resuscitation, we'll discuss rescue techniques for the patient who is failing at resuscitation, the utility of the burn navigator, and special populations.

Who pose unique challenges.