Ep 212 Burns Part 1: The first million or so years

Ardent spirits were first applied, then flaxied oil, and lastly a calcareous soap of the same oil and lime water laudanum, was administered freely, both externally and internally.

suffered much worse. The whole cuticle was separated and much of it was rolled up, especially that which covered the space between the wrist and hollow of the hand and extended up the inner side of the thumb as far as the middle of the second phalanx between these limits and the metacarpal bone of the little finger on one side and the corresponding bone of the thumb on the other. The true skin was killed and turned black. Immediately after

the accident. He immersed both hands in whiskey, then in a liniment of flaxeied oil and lime water, after which the affected parts were wrapped in rags dipped in a painter's mixture of the same kind of oil and white lead, ground together.

to direct the attention of the reader. Several causes seem to have conspired to depress the energy and disorder the sensibilities of his nervous system. Number one, the acute sensibility of the parts injured. The pain for several hours after the accident was excruciating, notwithstanding the liberal use of laudanum. Number two, the scene of concentrated horror under which the injury was inflicted contributed not a little to overthrow the

powers of the nervous system. Number three. The immersion of both hands extensively denuded of cuticle in a liniment of oil and white lead, seems to me to have contributed largely to the same effect. Number four.

or constitutional irritation which these causes generated. A great variety of applications were advised and employed for this formidable affection, but with little good time only has been efficacious. But even a period of nearly two years has not entirely overcome the effect.

So the author of that was a medical doctor named Daniel Drake, who was actually one of like a famous doctor at the time, and he wrote this about his own experience, and he was the editor of a journal, and he was like, I need to tell everyone about this, like all of these and I think the realization that he came to was, like all of these treatments. We have so many different treatments and none seem to have a positive effect.

is also unique. It's kind of interesting, huh. Okay, And what I really think and what I took away from digging really deep into this is that what burns really show us is just how incredible and how important of an organ our skin is, true, and how severe damage to that skin has life threatening consequences and long lasting consequences.

So I'm gonna walk us through the types of burns that we can see, burn severity and how we actually determine severe versus minor or major versus minor burns, and what is happening to our whole entire body as a result of a burn injury, and then save the like, what do we do about these burns for next week's episode?

structures with very minimal visible surface injury. But those are still going to be burn injuries, but deeper. A burn from a chemical, like say a strong acid, might cause coagulation necrosis, so your blood vessels are all clotting and all your blood is clotting, while a burn from an alkaline chemical might actually liquefy your tissues completely. WHOA, Yeah, So burns from chemicals are going to act a little bit differently, and they might differ in how we need

to treat them. You can think of frostbite as a type of cold burn, and those need to be rewarmed and watched. See our two episodes on cold and cold injuries. Hypotheth that what we call them, I think, So, yeah, I was like, what did we call this? Whereas a heat burn is going to be different, and so most of what I'm going to talk about, though it pro probaly applies to most all burns. They're really I'm talking mostly about thermal burns. So burns as a result of heat injury.

of burns worldwide. Once we know what caused the burn, then the next thing that we need to know is the severity of that burn. And the severity is a combination of the body surface area that's affected, so how much of your body got burned and the depth of that burn. And then of course we also need to look for whether there was any additional injury or traumas, especially in the case of something like a flame burn, you might have inhalational injuries or a chemical burn, you

might have other toxin exposures. You could even have like blunt trauma injuries, right, depending on how the burn was sustained. And then there's patient factors that might make someone more susceptible to severe outcomes from a less severe burn, like say a very young child or a very old person, et cetera.

still use for second, third degree. So we'll just go a little bit more detailed, Okay, And first I want to take us through our skin. And we've talked about our skin on a number of episodes before, including like our retinoid's episodes. Yes, but our skin is an incredibly important organ, and it's a layered organ, the largest organ in our whole entire body, and it's made up of several different layers. The top layer, the outside what you're

touching and what you see, is called the epidermis. And this is very very thin layer, and it differs in thickness depending on where on your body. So it's a lot thicker in places like the soles of our feet and our back, and it's a lot thinner in places like say, your eyes or you know, the backs of your hands or things like that. Underneath the epidermis is the dermis, and this is the layer that has a

lot of structure to it. It's a little bit thicker still, only on the order of millimeters, but the dermis is underneath that. And then underneath the dermis is a layer of subcutaneous tissue, so this is like fa and things like that. And then below that is when we get to muscles and bones. Okay, So the degree of a burn depends on how far through that skin layers. Through those layers of skin, we actually get. A superficial burn, or a first degree burn, is one that burns only

the uppermost layer, the epidermis. This you can think of as a bad sunburn, right, okay, blister, no, not a blister type of thing. Okay, So a bad sunburn. Your skin is red, angry, and it's painful, but beyond that, it's generally does not blister, okay, And it does not need any kind of specialized treatment, and you're not going to get a scar or any residual defects or anything. These type of superficial or first degree burns generally heal within a week or so, but no blistering. That is

when we get into second degree burns, okay. And what used to be just lumped as second degree burns is now into two different types. So the first is a superficial partial thickness burn. This is the one erin that will blister, okay. And so this is a burn that burns completely through the epidermis and then into the first part of the dermis, but does not go like deeply

into the dermis, okay. And so this is something that you might get if you burn yourself on a pan or the oven or like really hot you know, liquid that spills on you or something. These burns are very very painful. They might be red, they might be blistered, they might be very wet and kind of weep and you have to take care of these wounds. But you're

not going to need surgery to fix these wounds. Ye, because the layer of the dermis has not been completely burned through, and so your skin is going to be able to it's called re epithelialize. It's going to be able to make new skin to cover up this wound without a lot of additional help. Most of the time, you're not going to get a scar from these types of burns. If you do, it might just be pigmentation changes because of losses of like the melanocytes that are

in more of the epidermal layer. Okay, okay. Next is again within this considered second degree burn is called a deep partial thickness burn, and the deep partial thickness burns actually tend to hurt a little bit less than the first two, and that's because they burn deeply enough that

they're actually destroying our pain receptors in our skin. These burns tend to be a lot drier than a superficial partial thickness burn, so you don't necessarily have blisters, or if you do, they're just not quite as wet as a superficial burn. They often look either very dark pink or sometimes almost white, where they just look like it doesn't really look like there's anything there. It's just like

completely white, regardless of your skin color. And they're almost kind of pearly looking, rather like or like waxy looking a little bit. These generally do need surgery very often. These are deep enough that the skin is not going to be able to completely heal over this without some kind of surgical intervention, and that means that they're at

much higher risk of some kind of scar formation. There's not a huge leap then, from a deep partial thickness to a full thickness burn or a third degree burn, and this is one that extends completely through the dermis, so the epidermal layer and the dermis are completely burned

through all the way down into that subcutaneous tissue. In some cases it a burn can extend all the way down into our deeper tissues, which is sometimes called a fourth degree burn, or sometimes it's just lumped under this third degree, and that means that there's damage to the muscles or the bones, depending on how deep it goes. These full thickness burns are not painful because all of

our nerve endings have been destroyed. And I asked risk that erin, Yeah, because that just means that at the time of the injury, that specific area that sustained a full thickness burn, if you touch it, you will not feel that the way that if you touch a burn blister, it really hurts. But that doesn't mean that they're not painful in the long run, or.

all of this at the same time. If someone comes into a hospital with a burn, but total body surface area is how much of your body surface is covered by this burn, regardless of the degree, So you don't need to separate it by oh, you know this much surface area was a first degree versus second versus third. Here we're just looking at how much of your skin got burned. And this is actually the most important part

in looking at mortality is surface area. So how we classify something as a so called minor burn, This is actually a lot more. I won't even say contentious in the literature because I don't think anyone's fighting over it. But it really depends on the situation whether something is considered a severe or a minor burn. In general, most people don't require hospitalization for burns that cover less than

ten percent of their body surface. But that's a huge generalization because a burn on the face, a burn on the groin, a burn on the hands, even if it's significantly less than ten percent, might still require hospitalization as well as depending on the thickness or the degree of that burn.

to cause severe effects. But all of that is really like it so depends on the person, right, So there's not like a clear cut definition of like this is a major burn versus a minor burn, or a severe burn versus a non severe burn. But calculating that body surface area is a really important part of the care of a person and understanding how severe their outcomes are going to be. And the way that we do that

is there's a couple different ways. There's a fast and ready way kind of that is called the rule of nines, and that is that we just split up an adult body area into areas that are about nine percent. So our head is about nine percent of our body surface.

Our chest, the front side of our chest, and the front side of our abdomen are each nine percent, and same thing with the back, so that's like eighteen and eighteen, and then the front of our legs are nine percent, the back of our legs are nine percent, on our two arms put together are nine percent, and then an extra one percent for the genitals.

on our palm is about one percent. Okay, that's considered about one percent total, so you can use that to kind of estimate if it's less than nine percent or something. You're trying to get a rough estimate. So that's how we sort of calculate and estimate how severe a burn is.

And of course, like I said at the very top, our skin is the largest organ in our body, so damage even to a small portion of that organ has the potential to cause a whole body response, and the response that we see really depends on the depth of that burn, the surface area of that burn, and the person who sustained that burn and what their underlying conditions is.

But we can kind of understand how this process is going to go if we understand our basic inflammatory response and how our body responds to wounds in our skin, which we've talked about on previous episodes. I think on our Maggot's episode, we talked about this inflammatory response because anytime that our skin is wounded from a burn or a scrape or a scratch, our body follows a very predictable series of responses to try and repair that wound.

The very first thing is hemostasis right. We have to stop the bleeding because most of the time wounds bleed very often they don't in the case of burns, and we'll get to why that is. But the second thing that's going to happen is inflammation, and this is to bring helpers to the area in order to start the repair process. The third step is prolifer. We need to start making new cells to fill in the gaps that are left by this wound, and finally we have maturation

or remodeling. That's the finishing up that is really scar formation, because our skin pretty much always heals by scarring, so in the event of a burn, our body is going to attempt to heal by this similar process. However, because of some specific things that happen, especially in the case of a thermal burn, so a heat related burn, as well as the potential for a very large portion of our skin to be affected, the end result is often a pretty disregulated body response that can be really severe.

So unlike say a cut or a scrape that just has damage wherever that scrape actually happened, a burned wound actually has several different zones of injury. In the very center or like where the burn was actually sustained is

what's called a zone of coagulation. You can think of this as not necessarily the deepest part of the burn, but like the part that actually had contact with the hot liquid or the flame or whatever it was that caused the injury, and in that area the tissue is dead, the blood cells are coagulated, so there's no bleeding in that area because of the strong heat that was applied and that tissue in that area cannot be completely salvaged. Okay, Okay.

Immediately around this there is a zone of stasis, and in this area there is a lot of inflammation. So our body is trying to respond to that central area. It knows that there's something wrong here, but there's very

low levels of blood flow. There's a lot less profusion in this zone because of damage that was sustained and our body's response of kind of clamping down to try and protect that area, which has the effect that if that area is not addressed, then the damage from the burn can actually extend out over the next twenty four to forty eight hours.

So in the first forty eight hours, it's important to be able to find those areas and see how much tissue can be salvaged, especially and I'm talking really in the case of deep partial thickness, so like those more severe second degree burns or third degree or full thickness burns, right, Okay, this isn't necessarily happening in a superficial burn where it's just the epidermis.

risk of dying. And so that's where a lot of the inflammation comes into there. Yes, Yes, not necessarily the central point of the burn itself, because there's nothing left. There's no more tissue left to go to that is alive and receptive, right, right to do the remodeling first, exactly, So yes, in that tissue that is completely dead, our inflammatory response can't kick in there.

surrounding areas we have a lot of vasodilation. That means our blood vessels are getting larger, and that's to accommodate more flow. We see an increase in vascular permeability, so that means that our blood vessels are more leaky, and that is to allow all of the plasma that has our white blood cells and the inflammatory markers and the cytokines and all these things into the area to try and help. But unfortunate only what that ends up resulting

in is a lot of edema. So a lot of fluid in the area because the degree of inflammatory signals is so high, and this can be in and of itself very dangerous, especially in the event of like a circumferential burn. So think like a burn that goes around your entire arm, for example. Basically the fluid has nowhere to go and so that's going to increase pressure in that area. Does that make sense, yes?

And shock, as we learned in our sepsis episode, means a drop in your blood pressure enough so that all of your other organs are not getting enough blood. So this is incredibly dangerous. It can result in multi organ failure, kidney failure, liver failure. Your heart is not pumping out enough blood, and really it's because you're not losing blood, so you're not bleeding out, but you are losing so much fluid from this process that your blood pressure just

can't keep up. We can also see really bad fluid imbalances and electrolyte imbalances as well. So in this period what's really important is fluid resuscitation as well as management of these wounds to try and prevent all of this

stuff from getting worse. And in the case of those, if we have circumferential burns and things, there has to be like pressure relief, so you have to do some kind of surgical intervention, even if it's something small, to literally release that pressure so that you don't cause further damage to the tissue or the tissue downstream. That Okay, after that initial twenty four to seventy two hours after a burn, your body enters a new phase that's called

the hyper dynamic and hyper metabolic flow phase. And you can kind of think of this as your body like releasing all the stress hormones that it has so you're still alive. Your body has kept you alive for this first few days, and now it's recognizing that without a portion of your largest organ being able to thermoregulate, being able to regulate the water in your body, being able to protect you from infection. Your body is going to

have to compensate in a huge, huge way. So what we see our blood vessels actually clamping down, so a real decrease in vascular permeability. We see your heart rate going up. We see the small blood vessels or the microvascular of the area around that wound starting to heal and redistribute blood to these areas to actually promote healing rather than just like kind of freaking out like they

were at first. Right. And then we also see huge increases in our basal metabolic rate, so our body literally starts burning way more energy than it has in the past. And what is so wild about burns are that these changes in metabolism and total body functioning, like changes in cardiac output, changes in insulin and glucose regulation, changes in

heat production, last for years following a severe burn. Really, yes, So if we see body surface area burns of twenty percent or greater than these changes in metabolism can last for two or more years.

bad scab. So something that's completely black, completely necrotic, can be very thick, and it will take a very long time, if ever, for that wound to heal completely because again, if the burn extends all the way through the dermis, so a deep partial thickness burn, or a complete thickness burn so a late second degree to be or a third degree burn or greater, there aren't any like dermal cells left to re epithelialize, and so that wound has to heal like from the bottom up, and it's really

a slow process and in some cases it just never completely makes new skin again without some kind of wound management, So that wound might never heal and it might become a chronic wound, okay if you don't have any access to essentially surgical debreatment and then treatment for it. So that's mostly burns and kind of how severe they can be, what damage they can cause. There's obviously a lot of complications that can arise during the treatment of these burns.

You're at very high risk of infection because your skin is the main barrier from infection, and depending on what caused the burn, you might have additional like inhalational injuries, and smoke inhalation deserves its whole own episode because that can cause really severe injury. It deserves its whole, entire

own episode. But that's kind of like the main how we deal with burns in terms of how our body is responding to that burn, and the management is going to really vary depending on what you have access to and depending on how severe that burn is. But Erin, I have to assume that we've been subject to vulnerable to burns ever since I don't know forever, since we lost our fur, like furry animals can still burn, tell me.

organ failure. And then after that it's more likely to be infection or potentially other complications like if there was an inhalation injury or something like that. At the same time, gotcha o kyeah, Okay.

around the globe every year due to burn injuries. Burns are a routine feature of our lives as human beings, and that's been the case for a very long time. My story of picking up a white hot ember, not only is that a common story today, it's been a common story for hundreds of thousands of years.

Without fire, we would not have developed into the humans that we are today.

But our earliest confirmed insight into the treatment of burns comes from the medical texts from ancient civilizations that were used to encountering, you know, the Ebers Papyrus, the Hippocratic texts, medical treatises from China, writings by Shushruda, and so on.

The majority of these treatments for burns were centered on the application of like a goo or an ointment or a cream to the burn itself, to the actual location of the burn, with a little bit on pain relief and maybe early like debreedment type of approaches.

The Hippocratic texts recommend that for a burn, you should quote take melted fat of old pigs, mix it with resin and bitumen, spread it out over a cloth, warm it at the fire, and apply it as a plaster end quote.

the bark of a fig tree. To quote from a nineteen seventy seven paper by Thompson on the history of burn treatment, quote it would be tedious and not a little revolting to detail all the hundreds of variations on this theme and quote fair enough enough, But hopefully I've given you a small taste of the variations on the theme. And I think that there are two main takeaways with

this foray into ancient burned treatment. First, there are a lot of treatments, which suggests, of course, that this was a problem encountered frequently enough to keep trying new things.

barely a drop in the bucket. I mean, they were doing the best that they could with the knowledge that they had, and as that knowledge grew, so did their approaches, but not necessarily with success, just sort of there were

limitations for thousands of years. By the Middle Ages, the list of options for treating a burn had grown tremendously, so sure, still plenty of people were opting for raw onion slices, which remained popular for long, like a really long time actually, with Ambrose Paree employing onions and salt allegedly effectively in the sixteenth century. But there was one sizeable shift in focus over that time, and that was

sort of towards temperature. Physicians found that topical treatments that invoked a cooling sensation or were themselves cooling like melted snow, provided relief to those with burns, especially with superficial burns. Others suggested that treating like with like, so applying heat to the burn would yield more positive results, especially for those with deep wounds.

When it came to burns, what was needed to make any type of progress was consensus, first and foremost on how to measure the severity of burns and the rate of healing, because only then could you compare treatments or approaches. Only then could you pick lead ointment versus whiskey, ice water versus warming cloths. Only then could you have a hope of saving someone's life. How do you get consensus,

You gather data. In the early nineteenth century, Guillam Duputrin reviewed fifty cases of burn patients and followed their treatments and outcomes, and with this information he put together a classification system for burns organized by depth, similar to the degree system that many people are familiar with today that we just went through. His was not the first burn grading system overall, but it was the first to relate

burned severity, depth, and total area with mortality. With this system, doctors were not just treating burns, they were measuring them. Establishing this baseline was super important to compare different approaches. You know, again, turpentine versus lindseed oil might look the same in a severely burned individual, but if you tried them out on a more moderate or minor burn, you

might see a difference in healing, right. And it also opened the door to other kinds of treatments entirely, not just those based on topical ointments, such as surgical approaches you know, skin debreaedment and skin grafts, supportive therapies in the form of fluid replenishment pain relief. By the end of the nineteenth century, many, though not all, of the pieces were there to revolutionize burn care. They were just sort of scattered all over the place waiting for someone

to put them together. Up to this point, so around I'm going to say early nineteen hundreds, much all of human history, burns had remained out of reach for physicians, who could at most hope for the body's innate wound healing methods to kick in as they the doctors provided some modicum of pain relief. Frankly speaking, medicine had made no progress in increasing survival or healing in brace.

what funding for research has helped us to achieve, and how working across disciplines can make a huge difference, so that when we get there we get to go, oh my god, Oh my gosh.

but you know that there's also more. So if you want way more in depth information about the response and the path of physiology and all of this biology, don't you worry because we have the list of all of our sources on our website this podcast will kill You dot com under the episode STAB.