I'd like to thank everybody for allowing me to speak, and thank Dr. Neulicer for having me. So I'll go ahead and start off by saying I don't have any disclosures to make. I'm going to sort of talk about two and a half things, because there's some overlap with burns. So we'll go ahead and start while they're digging that out. So skin is important. I think we can all agree on that. It helps us get around, it allows us to look at each other, and does a lot of other things. And when they have a chemical injury, that injury is proportional to the concentration of the acid or the base or whatever's contacting it that's caustic, the amount of that, the depth of penetration. Alkali injuries tend to be some of the worst. They can continue to injure even 24 hours after the exposure. You get facet ponification, lots of hydroxide ions that cause protein damage, and examples of these are things like lime, bleach, even cement. Treatment for this is lots and lots of water, and then you can give them some more water. Acid injuries, injured by hydrolysis, and they generate heat, and the primary treatment for this initially is water. There are a few acids that have some other treatments that we can add on top of that. And acids are everywhere, then rust removers, car batteries, toilet and pool cleaning solvents, etching chemicals, our dentists use them on our teeth sometimes, and people who work with ceramics use them. Hydrofluoric acids are one of the acids that have their own special treatment, and these will chelate magnesium and calcium ions. You may not even notice the exposure if it's diluted first, but as you start to have intense pain, that's when you usually notice it, and the treatment for this is either topical or injectable calcium gluconate, and you continue to give it until the pain goes away. The pain may return in an hour or two, and that means you need to give some more. Phosphoric acid binds calcium ions, and the treatment for this is a half percent copper sulfate solution that you give topically, and you give this only topically because copper sulfate is toxic if you give it systemically. For anybody that's interested, if you have a clinical encounter, a chemical exposure that you're unsure what you should do with, like phenol, gasoline, or anything like that, you can go to burnsurgery.org and find rapidly good treatment recommendations. In terms of what's been on the exams, there haven't been a lot of questions on the exam about this, but in 2011 exam, there was this question, a worker in a chemical plant's involved in a hydrofluoric acid spill and presents to the ER with a burn to the dorsum of his hand despite copious water dilution. Management should consist of escharotomies and IV broad-spectrum antibiotics, neutralization wash with sodium hydroxide, phenol injection, polyethylene glycol injection, or calcium gluconate injection. And so, again, it's hydrofluoric acid, and that gets the calcium gluconate. So moving on to chemoinfiltration and extravasation injuries, when we're talking about these injuries, we have to break down the chemicals into whether they are just irritants or they're vesicants. Irritants are things that aren't inherently toxic, but they may promote inflammation. Vesicants are inherently toxic to tissue. They may form blistering, skin slough, tissue necrosis. There's two kinds of those, the kind that bind DNA, and those are really hard to get rid of, and the type that don't, and those are easier to metabolize and neutralize. So there are some inherent injury factors, the cytotoxicity of the chemical, the osmolarity of the chemical, the pressure of infusion, and the vasoconstrictive effects of the extravasation. So common injuries include vincristine and vinblastine. These are vinca alkaloids, and if you have an infusion center at your hospital, you may get called for these periodically, doxorubicin, which is an anthracycline, mitomycin C, cisplatinin, which is a platinum-heavy metal, fluorouracil, and meclorethamine, which are one of the nitrogen mustards and alkylating agents, and what's confusing about these sometimes is that they don't just say the name, they'll say, if you treat a vinca alkaloid, you know, and sort of have to know the class and the name of the most common ones. And then we all see pressor effects sometimes, especially if anybody works around an ICU. There's a nice article in the JHS in 2011 by Michael Hannon and Steve Lee talking about the treatment of extravasation injuries, and they give a chart of some injuries that some are common, some are not so common, and what treatment they recommend and the data to support that treatment. And there really isn't a lot of great data to support what we do, but this is still what we do. And so TPN frequently is seen, especially with kids, and what we normally see is just a lot of administration of hyaluronidase. Here they recommended a GALT flush-out technique, which the picture to the right is there. We'll discuss that in a second. Dilantin or phenytoin can be common, and this can actually be very serious if you can develop purple gloves syndrome, actually go on to need an amputation of the hand. Sometimes they're very benign, though, and hyaluronidase is the treatment of choice for this, and you can also try to do the GALT flush-out technique. And there are several others here, and we'll get to some of the common ones that have been The GALT technique was published with a retrospective review in 1993 in the British Journal of Plastic Surgery, and they basically looked at 96 cases over five years. Some got this technique, some didn't. This technique involves infiltrating the area in question with lidocaine, making four incisions, and then putting a needle in that's either a tumescent needle, a varus needle, or a liposuction cannula and flushing it with fluid and allowing that fluid to come out the other incisions. So you need to let that fluid escape so you don't increase the compartment pressure. That can even be added with liposuction of the subcutaneous fat there. So in the group that had this done, retrospectively looking back, there's about a 14% rate of tissue loss. In the group that didn't have this done, about 29% tissue loss. So about half the tissue loss for folks who got this technique. That being said, I myself have never performed it or seen it, but it may be something to have in your armamentarium. So when you're taking the exam, here are a few key things to remember. These are the things that have been tested year to year. So doxorubicin, which is an anthracycline. The treatment is dexrazoxine, or DMSO, plus cold. Vincristine, which is a plant alkaloid. The treatment has been warm compresses and hyaluronidase. Meclorethamine is treated with sodium thiosulfate and cold, and radiography contrasts. Modern radiography contrasts is a low osmolality, non-ionic, and so it doesn't cause near the problems that the old iodinated contrasts that had a lot higher osmolarity used to cause, and so this is pretty conservative. So there's this little chart that I stole from the University of Kansas Hospital that you can look up the chemical, look down, and see either a blue arrow or a red arrow. Red means heat it, cold means cool it, and then you can come down to see if there's sort of an antidote to give as well. And for this group up here, which includes the anthracyclines, you can see that down at the bosom, dexrazoxine can be used, or DMSO can be used. And these other things that you'll see there, like paclitaxel, TPN, flurieracil, they all get cold along with the anthracyclines. So if we put this into use and look at the 2011 exam, in the course of a CT scan, 100 cc's of non-ionic contrast dye extravagates into the antecubital fossa. The arm's neurovascularly intact when evaluated 30 minutes later. It's moderately swollen. The skin has normal capillary refill. What's the recommended course of action? And the options are discharge home with arm elevation, follow-up if symptoms arise, admission to the floor with hourly neurovascular exams with strict elevation, immediate surgical intervention with liposuction of the subcutaneous layer to remove edema and toxic chemicals, immediate surgical intervention to perform skin incisions to evacuate the edema and wash out toxic chemicals, or immediate surgical intervention to perform four fasciotomies. Again, it's non-ionic contrast, it's a low osmolality, and so we should be safe with just elevating their arm and allowing them to follow up as symptoms arise. A 39-year-old cancer patient sustains extravasation of concentrated doxorubicin, which should be administered. So again, it's doxorubicin. This is an anthracycline. On our chart, let me go back, that is in the column that has a blue arrow for cold, and then it gets dexrazoxine. If you look at these other answers, dexamethasone is a steroid. It's not used to treat any of these things. Methylsaline is just going to add fluid to the compartment. Calcium gluconate, we know, is for hydrofluoric acid. And fentolamine, we all know, is for pressers. So correct answer, D, dexrazoxine. Here's our chart again, doxorubicin up here, blue arrow gets cold, and down to the dexrazoxine. 2010 exam, which of the following agents is used at the site of meclorethamine chemotherapy extravasation? So we already know that this was used for the anthracyclines like doxorubicin, so that's not it. We know it's not DMSO because that's also used for anthracyclines like dexrazoxine. Polyuronidase injected through the existing IV or subcutaneously at the extravasation site, that's usually used for vinca-alkaloids like vinblastine, vincristine, sodium thiosulfate with sterile water, or glucocorticoids, again, we know that we don't use glucocorticoids for any of this, so the answer is going to be sodium thiosulfate. If we look at the chart again, meclorethamine, you follow it down, we're going to want to cool it and give sodium thiosulfate. 2009 exam, extravasation of vincristine treatment includes application of ice, injection of DMSO, hot compresses and injection of hyaluronidase, administration of sodium thiosulfate, or subcutaneous injection of sodium thiosulfate. So we know that these are for meclorethamine, that was a question we just saw. And if you look at the chart, vincristine is one of the vinc-alkaloids, these like warm compresses and hyaluronidase, and so the answer is warm compresses and hyaluronidase. 2008 exam, cold compresses as a part of supportive care is contraindicated in acute extravasation of which of the following chemotherapy agents? So vincristine, we know that that's a vinc-alkaloid that likes warm things, doxorubicin likes it cold, mitomycin C is in the column that likes things cold, cisplatin and fluorouracil are all in that right side column that like things cold, so vincristine is what likes warm compresses. So if you think about things in sort of those four categories, you should be able to get any question right, because they continue to recycle vincristine, vinclastine, doxorubicin, meclorethamine. So moving on to frostbite, cold exposure incorporates ambient temperature, wind chill, which is convection, humidity, moisture, metal contact, which are conduction, and the duration of those factors. People with increased susceptibility to frostbite are those who are acutely intoxicated, people with psychiatric illness, peripheral vascular disease, smoking, people with previous frostbite, people who've made the bad decision to stay out in the cold before, darker skin tones, and alcoholism. Systemic response to cold begins with cutaneous arteriovenous shunting, and then as we progress to mild hypothermia, it starts shivering and cold diuresis, so remember when people come in with hypothermia, they need fluid resuscitation because they've diuresed. Severe hypothermia has progressive metabolic slowing, and when you get to severe hypothermia, which is a core temperature below 84 degrees Fahrenheit or 28 degrees Celsius, you can get progressive unconsciousness and cardiac arrhythmias. So the pathology involves the development of extracellular ice, which then brings fluid out of the cells, so the cells become dehydrated, and you get protein denaturation, your DNA synthesis is off, your red cells start sludging in your capillaries as you get endothelial cell dysfunction, and you get skin injuries secondary to vascular injuries, so your skin has to start surviving as a skin graft. The severity is graded into four grades. The first degree is where you have just white, yellow, firm plaques. Second degree is where you have clear, milky blisters, erythema and edema. The third degree is hemorrhagic blisters. Fourth degree is a deep cyanosis. The first two are considered superficial injuries. The second two are considered deeper injuries. This is not to be confused with chill blains, which are chronic intermittent cold exposure and humidity problem, usually of the foot, and that's associated with connective tissue disorders, or trench foot, which doesn't actually require exposure to freezing temperatures, but persistent wetness. So the treatment of hyperthermia begins with establishing an accurate temperature. The patients need to be on telemetry in case they develop arrhythmias, central venous lines, and a Foley catheter for resuscitation. Rapid rewarming is the key treatment here, and so we'll put them in water that's 104 to 108 degrees Fahrenheit in what used to be described as the Hubbard tank, and they need fluid resuscitation. If you have a level one that can heat the fluids, that's great. And for people who are severely cold, who are having arrhythmias, they may even need to go on cardiopulmonary bypass, and that can have a heated circuit, which will help as well. The arrhythmias tend to be self-correcting as their temperature warms up. You may notice as you start to warm them that they have an afterdrop, where their core temperature begins to get colder, and that's just because they're finally circulating that cold blood out of their extremities back to their core. So they need to be admitted, they need rapid rewarming, and we need to avoid refreezing. So if you're going to rewarm somebody, but you're not at their ultimate destination of care, it's important that you think about whether they're going to be exposed to cold again when you evacuate them. If they are, do not rewarm them yet, because the frostbite injuries are additive. So it's better for them to have a longer frostbite injury than to have an injury get rewarmed and then have another injury. So the treatment of blisters, if these are the clear or milky blisters, is to aspirate or to breed them to get out the arachidonic acid metabolites, which continue to injure the skin. The wound care consists of aloe vera, which is a strong inhibitor of arachidonic acid metabolism, splinting, elevation, and hand therapy. We tell them no smoking. They get aspirin. They may get pentoxifeline. They get penicillin, 5,000 units every six hours for two to three days, and definitely a tetanus update. And there's some evidence that maybe dextran helps, maybe HBO helps. Reserpine has not been shown to help. The old mantra of frostbite in January, amputate in July, it was intended to help preserve tissue so we wouldn't debride tissue that may ultimately end up being viable. But it prolongs the morbidity. We can do earlier surgery if we have a way to help predict what's going to be viable. And for that, we use triple-phase bone scanning with Technician 99. Classically, this is done two days after the injury to predict the amputation level. And we look for the flow bone pool images to see what has perfusion and what doesn't. More recently, trials have started using immediate post-warming bone scans to try and evaluate if there are flow voids that can be treated with TPA. Triple-phase bone scanning has a strong correlation with final amputation level. MRI is less useful for this. In two trials that we'll talk about, in general trauma 2005, people with frostbite who came in who had no Doppler signals in their digits after re-warming either had angiography performed or triple-phase bone scanning, if there were vascular deficiencies there, they received either intra-arterial or intravenous TPA. Out of 174 digits at risk, only 33 ended up being amputated. The people who didn't respond were people with cold exposure for greater than 24 hours, warm ischemia times greater than six hours, or multiple freeze and thaw cycles. A second study out of Utah in 2007 treated seven patients within 24 hours of their injury. They treated those patients, or I should say followed them prospectively, but compared them to control data that was retrospective. And they found the digit amputation with TPA was 10% versus 41% without. They used intra-arterial TPA through either femoral or brachial sheath, and they had one complication during that series, which was a retroperitoneal hematoma. The 2010 exam, which of the following studies provides early indication of eventual demarcation and severe frostbite injuries. I think we may have beat this one to death a little bit, but it should be C, technetium bone scan, and we're seeing this performed earlier than later as we have new treatments available, i.e. TPA. After being outside for less than 24 hours, a 34-year-old mountaineer presents with severe frostbite involving both hands after a rapid re-warming, technetium 99 bone scan is obtained that demonstrates no blood flow to multiple digits bilaterally. When intervention should now be utilized, the whole point of getting the early technetium scan is to see if they are candidates for TPA therapy, and so intravenous tissue plasminogen activator therapy is the correct response. A 60-year-old homeless man is brought to the emergency room after spending the night outside in subzero weather. On exam, all of his fingers are white, cold, and without capillary refill. For treatment, you recommend immediate re-warming of his hands in water, 140 degrees Fahrenheit, pain medication, tetanus prophylaxis, antibiotics, and ibuprofen. The role of the ibuprofen is to supplement pain management, decrease red cell sludging, limit platelet adhesiveness, decrease sympathetically mediated vasospasm, or decrease the toxicity of arachidonic acid cascade, and we are all about decreasing the toxicity of the arachidonic acid cascade. A 38-year-old mountain climber has a frostbite injury involving both hands. He's evacuated to a mountain first aid station but cannot be transported by snowmobile to a permanent facility for 12 hours. What treatment should wait until he's at the permanent facility? Core body temperature re-warming, tetanus prophylaxis, cold water baths, rapid re-warming at 40 to 44 degrees Celsius, or oral antibiotic prevention. So we don't need to keep them cold. It's okay to let them into the warm room and try to warm them up, so A is not correct. If you have access to tetanus prophylaxis, then you should give it. Rapid cold water baths are not anything that we need to be concerned about. Rapid re-warming at 40 to 44 degrees Celsius is what we should avoid if we think that the patient's going to have a potential exposure that could refreeze and cause another frostbite injury. And that's it. Thank you very much. Thank you.

burns

chemical injuries

frostbite

skin importance

treatment recommendations