Hello, I'm Dr. Heather Lee Bailey, an emergency medicine intensivist and a past president of the Society. This talk will be on when the environment causes trouble. You can see we have a lot of subjects to cover. Several of these are specialties in and of themselves, so we will just focus on some key features of each of these entities to help you care for these individuals. You may be thinking, what's the relevance of this topic and these topics, because I don't care for burn patients, I don't see drowning victims, well, these are some of those orphan topics that each exam has somewhere between 5 to 15% of their exam questions are on these orphan topics, and if you're not a good test taker or perhaps you're having a bad day or you've been up all night caring for a critically ill patient, this may just give you enough points to bring you over into that passing line. And the others, these are the topics and the situations that you will face in your everyday life outside of the ICU, perhaps at your child's soccer game, at an outdoor concert, or in your neighbor's backyard pool. We're going to start with the extremes of temperature first. There are two types of heat stroke, there is exertional, which is typically young, healthy individuals, military recruits, athletes, you know, we're in the heat of the summer, football practice is starting up, and every year it seems there is a tragedy during some of these athletic practices. If these individuals are identified early and treated rapidly, there's almost 100% survival. This is the classic heat stroke. This is during times of sustained heat duration, such as what's going on in the Northwest right now where there's days and days and days of temperature in the upper 90s, especially if the individuals do not have access to air conditioning or cooling. People who have comorbidities are at higher risk and the extremes of age. Mortality can be as high as 50%, and I think there's a typo on the original slide, so it is up to 50% and is usually from multisystem organ failure. Three main risk factors for heat illness, one, your body has increased heat production due to an intrinsic problem that you have, medications that you're on, or underlying substance abuse. Also can have trouble with decreased heat loss. This is where those environmental factors come in, the extremes of age, and you see there are multiple medications, and this is only a handful of those that can contribute to the inability to lose heat from your body. Then there's impaired mobility, extremes of age, those that have physical and mental impairment put them at risk for not being able to take themselves out of a hot or a cold environment, and we'll get to that next. The classic findings of heat stroke, typically the core temperature is greater than 40 degrees centigrade, and there must be CNS dysfunction, that is the hallmark of heat stroke. There's a whole range of heat illness that approaches that, but once you have CNS dysfunction, that is heat stroke. These patients can be anywhere from altered to seizing to francoma. Not sweating, coming in with that dry skin, anhydrosis is only present in about 50% of the classic heat strokes, so don't be fooled if the patient is very sweaty. You have cardiac instability, and both the liver and the kidneys can have direct thermal injury. Kidneys are also susceptible to volume loss, leading to acute kidney injury, and of course rhabdo for muscle breakdown from direct heat injury as well. The intestines get heat stress. What happens is the body tries to cool itself, the blood shunts to the periphery to try and offload heat, leading to decreased blood flow to the intestines. Decreased blood flow, decreased oxygenation leads to cell ischemia, and that increases your wall permeability and endotoxin translation. There is suggestion that using propofol may be helpful in these individuals to help protect the gut with propofol inhibiting the nitric oxide and decreasing the pro-inflammatory cytokines. Somatostatin is also thought to be helpful to protect the intestines after heat injury because heat injury promotes trypsin release, and somatostatin inhibits the trypsin secretion. Now for prevention that we have on the right-hand side, typically not going to be helpful in the emergency, in the ICU, but you may have individuals who are low on these levels if you check them, and supplementation may be helpful, but what it is truly aimed at is in the military and the athletes, making sure that their levels are appropriate, and if you're in the situation such as what's going on in the Northwest right now with that prolonged heat, having, making sure people are up with their levels of zinc and selenium because having low levels of this does put them at risk. Rapid cooling is the mainstay of treatment. There's several different ways to do that. You can use both evaporation with cool mist and fans for convection. You can submerge individuals in ice baths and recommended using, at least in the emergency department, a lot of times we actually use a body bag and fill it with ice water to cool the individuals rapidly for, by conduction. The ice water immersion typically works better in the young individuals. One of the problems with putting people in the ice water is that it's very difficult to keep their IVs in place, very difficult to keep their leads on, and the elderly and those with more comorbid diseases may do better with evaporation and convection because of those reasons. Use IV benzos to prevent shivering. You don't want to have the patient shiver and increase their heat. And when they're not responding, you're still very, very hot. They have CNS instability, autonomic instability. You may need to use core cooling. There's no role for antipyretics. They do not help. And if you do need pressers, norepinephrine is not ideal because it decreases your cutaneous heat exchange. Not surprising if your patient has any of these poor prognostic factors. The one thing that we can do is make sure that there is no delay in cooling. As soon as you've identified these patients that are at risk for heat stroke and you're concerned about heat stroke, you need to start cooling them immediately. Ideally, even before they've come into the hospital. Going to the other extreme, focusing on the cold. Normally, we lose heat by radiation and then a little bit by evaporation. But as you can see with conduction and convection, a dramatic increase in conduction with heat loss if your clothes are wet or you're in cold water. And we all know what the difference in that windshield temperature where it's supposed to be 40 degrees, but the windshield takes it down to 25. Risk factors, not surprising. If you do not have a place to live and you're out in the elements, anyone who has problems with peripheral circulation and smokers because of that problem with peripheral circulation are at also increased risk for cold injury. Do you need to know a bit about frostbite? Because unlike heat injury, typically only those who have heat stroke are coming to the ICU. Your patient who has had hypothermic exposure and is core body temperature cold may also have frostbite at varying parts of their body. Superficial, the skin underneath, the tissue underneath is not, is going to be soft versus when you have deep tissue loss when the underlying tissue feels like rock or hardwood. The treatment for this, the best is to rapidly rewarm them in immersion, warm water circulating bath. You do not want to rub the skin because that will add to tissue breakdown and damage. You don't want to debride intact blisters. Leave those blisters intact because it's been found that they do better healing down the road. So your goal, if your patient is also suffering with frostbite, is you want to prevent further tissue loss. Extremities can be splinted and wrapped and elevated. Non-steroidals, if your patient does not have a kidney injury as well, they inhibit the arachidonic acid cascade and slow down with the frostbite. Topical aloe vera, not a wives tale, actually helps frostbite patients and improves the healing because it inhibits the thromboxane. Do not debride the blisters, but some individuals recommend if there's a tense blister or a large clear blister that you can aspirate those, but try to do your best to leave the skin intact. And debriding is delayed. You want to wait 60 to 90 days for the wound to demarcate. The saying is frostbite in January, amputate in July. Know that there's three ranges of hypothermia, mild, moderate, and severe. Accidental hypothermia is any temperature is less than 35 degrees centigrade. In mild hypothermia, your patients can still shiver. They vasoconstrict to try and generate heat and maintain their core temperature. Once you hit that moderate temperature, your patients lose the ability to vasoconstrict, your metabolism is slowing, they are unable to shiver, so they rapidly are going to progress into the severe. There's two levels of severe hypothermia. Both of which patients will be unconscious in the mild or less severe, severe hypothermia will still be able to obtain vital signs. And then in the most severe, when your core temperature gets about that 25 degrees or less, patients are going to appear dead. So first question, all of the following are correct about hypothermia, except one, central venous pacing should be avoided because of heart irritability. Two, hematocrit increases as core temperature decreases. Three, a rectal probe is indicated for temperature monitoring in moderate to severe hypothermia. Or four, the presence of an Osborne wave is indicative of hypothermia. You can think about what your answer is for a moment. Hypothermia makes the heart irritable, even transferring a patient from a stretcher onto a bed or moving them in the bed can induce B-fib at very cold temperatures. There needs to be core temperature monitoring. Esophageal temperature probe is what is most recommended, preferably in the lower third for the most accurate reading. Rectal probes, especially in the moderate to severe hypothermic patients, probably going to be in frozen stool, and so you won't have an accurate temperature. The Osborne wave, and hopefully you should be able to see it at least in your packet, even if my picture is blocking it, the height of the Osborne wave is proportional to the degree of hypothermia. So even before you're able to measure what their core is, the higher that Osborne wave is, the more cold that they're going, the patient is. Being cold shifts your oxygen, your oxyhemoglobin dissociation curve to the left, and so you have decreased oxygen to the tissues, so even though their PaO2 on their, from their blood may be okay, the tissues may actually be severely hypoxic. And your hematocrit increase is about 2% for every degree drop in sonic rate of temperature. Need to rewarm these patients. There's both external and core rewarming, passive and active for, passive for external and then active for the others, and the colder your patient is, obviously the more invasive that you need to, and aggressive that you need to be. And here you can see a guideline of what you can expect. Warming up the environment, temperature is going to go up maybe two degrees an hour, versus if you're using VA or VV ECMO or bypass, the temperature is going to dramatically increase, and that's if you have a very cold patient, it's the best way to warm them up if you have that ability. If your patient has cardiac arrest, obviously you want to initiate CPR. This is the time if you don't routinely use a compression device that you dig it out from the corner or the back closet or wherever you have it, because this resuscitation is going to go for hours. If you have the ability to use extracorporeal support, you want to initiate that as soon as possible. You can try initially if you, looks like your patient's in fine B-fib, an initial defibrillation and one round of meds. Typically, that doesn't really do much, you can do another round when you hit 86 degrees, and then you hold off until you get to about 32 unless your patient's rhythm changes. No one is dead until they're warm and dead, so you do not pronounce anybody until they're at least 32 degrees sonograde and have no vital signs. Exception to the rule, and you'll hear a lot of exceptions to the rule in these environmental cases, is there is data out of avalanche victims in patients whose potassium is greater than 10, obviously not hemolyzed, but a potassium greater than 10, that none of those individuals have survived, and so you could potentially use potassium greater than 10 as another stopping point. A few complications, a physiologic one, you get core after drop, if you're warming just using external warming devices, the periphery warms first, the cold blood goes back to the core, and the core temperature drops even further. So if your patient is anything more than just mild hypothermia, you really need to do both external and core rewarming. Coagulopathy is common. Our enzymes are temperature related, so you have problems with coagulopathy. Rabdo is common. And there's also the problem with hypotension, because you develop severe dehydration from cold diuresis, so these patients do need fluid resuscitation. Moving on to burns, we're going to talk a bit about fire and electricity. It's actually the fourth most common trauma worldwide. More than 11 million people is probably an underestimate, because the majority do occur in the lower middle income countries. In the United States, in a normal year, about a half a million people seek care to the hospital, of which about 40,000 are hospitalized, three quarters of which end up in burn centers. And the percentage of individuals who die, a lot of those do involve smoke inhalation. It is not surprising. They're at increased risk of death. The bigger the burn size, the deeper the burn size, older population, and if you suffer, smoke inhalation. The nomenclature has changed. There's no longer a first, second, third, or fourth degree. It's been changed to the level and depth of injury, so superficial, partial thickness, full thickness, or subdermal. You need to estimate the size of the burn. This is important for both care and prognostication of these individuals. There's several different ways to do it. There's a London Brouwer chart. There's the rule of nines. I'll show you charts in just one moment. Or the quick and dirty way is patient's palm and fingers is about 1% of their total body surface area, so you can estimate using that. There's something called a revised bowel score, which is the age plus total body surface area, and if that number approaches 140, there's really little hope for survival, so it can help guide therapy and inform patients' families. Here on the left-hand side, you see the London Brouwer chart. It's much more broken down. The numbers are going to be much more accurate as best as you can versus the rule of nines. It's more of a guesstimate of the amount of burn, but that's okay to start with. Burns obviously need to be cleaned and debrided. If you're going to be using the topical ointments for moisture, they recommend using them for no longer than a week. There are several different entities that you can use to put on the burns. The silver sulfadiazine should only be used on the body, not the face. If it's used on the face, it actually can uptake that silver tone that is permanent, so you turn your patient into a tin man, and you should not be using silvadine on just the superficial wounds, that old first degree, because it does impair re-epithelialization. You can also use medigrade honey. That's also acceptable. One of the recommendations for the topical agent on your face is using vasotracin. If you have biologic dressings, you can use those as well. Any circumferential burn needs an early escharotomy to help salvage the underlying tissue. And in patients, you're not at a burn center and you still have open significant wounds at two weeks, you need to have the patient evaluated by a burn expert or potentially transfer them. Patients have a lot of volume loss. There are several different formulas that can be used. The two common ones are the Parkland and the Modified-Brook formula. They're in MD-Calc. I think that you would not be asked to calculate this on an exam, because this is not a burn focused exam. But it's important to note that the Parkland formula tends to overestimate the amount of fluid that is needed, especially if you're using a less definitive measure such as the rule of nine. So you have the potential to overestimate the amount of fluid. But both of these, you give the first half of the fluid in the first eight hours and then the rest of the fluid over the next 16. Patients with burns are especially prone to developing a hypermetabolic response and a catabolic response in patients who just have more than 20% total body surface area. That is not a significant amount. You have the anterior part of your chest is almost 20%. One leg, both arms, adds up to 20% very quickly. Leads to muscle wasting. And if this progression is not stopped, they develop multi-system organ failure and death. One of the things you can do for your patients is make sure that the room is cooler. The burn tissue, as we already discussed, needs to be removed. And then the open areas should be covered with some type of barrier. Pain control is key in these individuals. Not only are they probably in severe pain if they're not having total third degree or deep burns, but pain also is a driver of their metabolism. Oxandrolone has been recommended to be used. It's been tested. It's a testosterone analog. It promotes anabolism in older patients. But you don't see the effect for a couple weeks. It does help restore lean body mass and has been showed at least in the elderly burn population that it decreases the length of stay. Nutrition is very important. You want to use nutrition with a low respiratory quotient. These patients are also prone to insulin resistance. Again, common in the geriatric population. Propranolol has been shown to be useful in pediatrics. There is no good literature at the moment on the use in adults. But it may be something to consider. Recent information out looks at the importance of feeding. We talked about the importance of nutrition. We all know the importance of nutrition for the body to help heal itself. But this is focusing at feeding the gut early within four to six hours. Not four to six hours to the ICU. Four to six hours from time of initial injury. They found that that improves outcome in these individuals. Your amount given is based on your body surface area. More or less than 20%. And they recommend about two grams per kilo of protein in these individuals. You need to consider transferring to a burn center if you are not a burn center. And here's the criteria to review. Partial thickness burn of greater than 10%. That's not a lot of burn area. Burns to sensitive areas, face, feet, genitalia, perineum, major joints. If they suffer burn from either electric injury, including lightning, chemical burns, inhalation burns, anyone who looks like they're going to need long-term burn rehab. These are all considerations for going to a burn center if you have that ability. Now, we were supposed to be in downtown Chicago. And in downtown Chicago, you're familiar with the great fire of Chicago of 1871 that displaced 100,000 people, lost their homes. And Mrs. O'Leary's cow has been immortalized in song and poem. And about 25 years ago, you'll be happy to know that the town council decided that the cow was not to blame. It was actually a human error. So, when burns from a fire, everyone initially needs 100% humidified oxygen. You need to intubate early in patients who've got inhalation injury. They've got evidence of burn around their mouth. They have circumferential neck burns or any evidence of respiratory compromise. You must consider carbon monoxide and cyanide. Carbon monoxide level is easy to obtain. It's going to come back on your blood gas. But cyanide is usually a send-out level. So, you need to just treat the patient. One of the suggestions is if you have a very high lactate or a rising lactate, you should consider cyanide. For the carbon monoxide, it's hyperbaric therapy. For cyanide, depending on your institution, you may have a thiosyanate, what used to be the old Lilly kit, or hydroxycobalamin. So, discuss that with your pharmacist. Next question. Next question. 44-year-old man is found collapsed in a house fire, he's placed on 100% non-rebreather, he's currently sleepy but answering questions, he has no obvious airway compromise, his minor burns on his extremities, he complains of a headache and vomiting. Which of the following is an indication for needing hyperbaric therapy for carbon monoxide poisoning? One, a carbon monoxide level of 20, headache, loss of consciousness, or vomiting. So think about that for a moment. And the main indication in this gentleman is any history of loss of consciousness, he was found unresponsive. Some will suggest taking them to the dive chamber at a carboxyhemoglobin level of 20. Everyone is in agreement once the level is over 25, obviously coma, and these seem self-explanatory. And pregnancy, if your patient is pregnant and there's evidence of fetal distress, some individuals will take a pregnant individual to the dive chamber regardless because there's a much higher fetal affinity of fetal hemoglobin to carbon monoxide than in the maternal. Inhalation injury is an independent predictor of mortality if the individual has burn to their lungs, that is a much higher rate of mortality. Get direct toxic effect. The smoke has a smaller, lower molecular weight, so it actually can travel deep into the airways down into the alveoli, causing thermal burns, edema, inflammation, can damage your ciliary function. So you get heavy secretions, atelectasis, and impaired gas exchange. The heat can also cause steam burns, and there are sometimes chemicals in the smoke which can lead to bronchoconstriction. Again, that increased permeability and vasodilation, get these thick exudates and cast formation. And all of this leads to impaired oxygenation. Some recommend getting a CAT scan for injury prediction. I think if it will benefit your patient, it's something to consider. If you bronch the patients, there is an injury score that you can use to grade their injury. Bronchodilators are useful, and both albuterol and nebulized epinephrine may be helpful in these patients. Eucalyptic agents will typically be necessary for those thick casts. Using the N-acetylcysteine breaks up your disulfide bonds in the mucus to help thin it out. And you can give the NAC nebulized with heparin, and that's been shown to improve mortality, have better lung compliance, less edema, decrease your time on intubated, and decrease your ventilator days. Electricity. A little bit of high school physics here. You have Ohm's law, which is current is voltage over resistance. Voltage is the difference in electron potential, and high voltage is considered anything over 1,000 volts. Current is the number of electrons moving or amps. And just like many things in life, electricity prefers to go by the path of least resistance. So, and that decreases with increasing fluid content. So, nerves, blood vessels, and wet skin are very good conductors of electricity. There's the two types of electricity. There's AC, which is your household current. It's actually more dangerous at a much lower amperage. When you get that little shock, it's just one to four milliamps. There's the let-go threshold, where if you get a hold of something that's, has electric current in it, and you've got both hands on it, you get sustained tetany, and you actually cannot let go. So, that's why if you're unsure about something being, having electricity, A, have an expert evaluate it, or only touch it with one hand so you don't get stuck. And once you get about 70 milliamps, you have cardiac depolarization and V-fib arrest. Direct current is completely different. Your victim tends to be thrown, so you're going to have blunt trauma as well as electric burn. It's common with high-voltage electronics. Lightning, we'll talk about lightning in just a minute. And the strange, interesting thing of this DC injury is there really is minimal external damage. And you may not know what happened to the patient. You may just find them down at a worksite. You should always consider that they've had a DC injury. Cardiac arrest is very common in these severe injuries. One of the things that you should look for in the ICU is the delayed problem. Obviously, you'll have rhabdo from muscle injury, but the eyes and the ears, these individuals are prone to corneal burns, retinal detachment, and late-finding cataracts. If you have an individual who's having an electric injury, you want to make sure they are a notabee of that looked later on for cataracts. Ruptured TMs are common, and sometimes in someone who's been thrown after DC shock, the only thing you may find externally is a ruptured TM. One other thing is on your trauma, your tertiary scan that you're doing in the ICU, you want to evaluate for posterior shoulder dislocation. This is a very common injury in the individuals who are thrown and very easily missed. So if your patient wakes up and says, oh, my shoulder hurts, I can't really move my arm, you need to evaluate for that. All these patients need to be monitored cardiac. You need to monitor their urine output. Don't forget about tetanus. Usually the emergency department is quite good with this, but don't forget to give tetanus in these individuals. And they are at high risk for both arterial and venous thromboembolus formation. Again, downtown Chicago, the Sears, the Trump, and the Hancock building all being hit at once by lightning. Lightning injury is a DC flashover. Causes both direct thermal injury, and then you can have steam burns or clothes actually just evaporate off the individual. I had a colleague had a case back in Philadelphia years ago where they were brought in by the police because they were running naked through the streets, screaming and acting strange. When they got them in to evaluate them, they actually had the burns, the classic like kind of fabrication of feathering pattern of lightning. And it turned out the individual had a flashover from a lightning and had a burn where his belt buckle had been and where he'd had a chain on his neck. There's another exception to the rule. If you are at a mass casualty scene or giving command for a mass casualty scene from a lightning strike, we've heard cases throughout the year, sometimes outdoor concerts or Boy Scout camps where multiple victims at the same time, normally in mass casualty, anybody who is not breathing or doesn't have a pulse, you go on to the next victim. Here's an exception to the rule. Lightning injury can cause a systolic arrest, but for some reason, cardiac activity can just spontaneously start back up again. So if you're at a mass casualty scene or giving direction for it, they need to resuscitate those who appear dead. You're going to be unable to evaluate what's going on. You can have anisocoric pupils or dilated pupils, and these can persist for hours to days. There's also a phenomenon known as coronal paralysis where you get mottled extremities, loss or decrease in pulses, and it's from sympathetic activation and extreme vasoconstriction. This typically resolves over the first 24 hours. Now we're going to focus for the last bit on water-related injury. Drowning, the official definition that's been about for about the last 25 years or so, is the process of experiencing respiratory impairment from submersion or immersion in a liquid. All victims who have a drowning event are drowning victims. It's either fatal or non-fatal. This near drowning and other terms still sometimes is used in literature, but that is not correct. There's at least half a million deaths worldwide. It's probably a gross underestimate, about 4,000 deaths in the U.S. One of the reasons accounting drowning deaths is difficult is individuals who drown during an environmental disaster such as Hurricane Katrina or Harvey or other disasters around the world are not counted as drowning deaths. They're listed with the hurricane. Also boating accidents that have drowning deaths, those are not counted in the drowning deaths either. It's the number one cause of death of boys worldwide in that 5 to 14 age group, top five cause of death in children in about half of the countries in the world that give data. And for every one death from drowning, there are another four individuals evaluated in the emergency departments. This is a significant problem. The risk factors are not surprising, but the one I want to point out to you is the hyperventilation. And guaranteed either yourself or your friends or your kids have done this. If you swim as a pool as a kid, you stand there and you think, oh, I'm going to swim underwater. I'm going to race. Let me take a couple of deep breaths because I want more oxygen. Well, we all know there's only 21% of best oxygen in the atmosphere. So what the child ends up doing is hyperventilating, blowing down their PCO2, but their oxygen stays the same. So they go and they swim under the water as their oxygen level falls, their PCO2 starts to rise, but it does not trigger the need to take a breath because it has not reached the threshold. So oxygen falls faster than the PCO2 rises. And then the individual goes hypoxic, loses consciousness and drowns typically when they could have just stood up in the pool. So if you see this activity occurring, please educate the kids who may or may not listen, but keep a close eye on them because this is a tragedy waiting to happen that is easily preventable. So in individuals who either are not hyperventilating or have not had some type of cardiac arrhythmia or medical emergency in the water, they start to panic. They start gasping for air. And then as they start going underwater a couple of times, they hold their breath, they become air hungry, they struggle to stay above water. And then you've got that reflex inspiratory mechanism that leads to hypoxia. So either they're under the water and the body overrides the fact that they're underwater and they take a breath. So you either aspirate or you get reflex springer spasm, they lose consciousness, they become apneic, and then if not pulled out and resuscitated, then they die. The cold diuresis we talked a little bit about in the hypothermic patient. These individuals have early vasoconstriction, shifting the blood to the central core. Your body senses that you're actually have volume overload, even though it's false, leads to decrease in your antidiuretic hormone, which leads to hypovolemia and hypotension. This is important because if the patient is in the water for a period of time and has this, how you rescue them is important. You do not want to take them out vertically because then have all their blood up in their chest. And as they're removed from the water, the pressure from the water is gone and they remove vertically and essentially their blood volume drops down to their feet because of gravity. And they can have sudden cardiovascular collapse. These individuals should be raised horizontally out of the water to prevent that until you can start their volume resuscitation. Fresh versus salt. Used to think that was very important. In reality, it probably doesn't matter very much unless you happen to drown in the Dead Sea, which has the highest mineral content and those individuals can develop electrolyte abnormalities. But typically that doesn't occur. They've studied and that to aspirate and change your blood volume, you need about 11 milliliters per kilo to change your electrolytes is double that 22 milliliters per kilo. And in those individuals who don't die in the non-fatal drowning, you only aspirate about three to four milliliters per kilo. So in general, it is not a problem. Regardless of salt or fresh water, you develop decreased lung compliance. You get surfactant washout, you get BQ mismatch, shunting, and that all leads to acute lung injury. What does potentially matter though is what is in the fluid. Is it water? Is it some other type of chemical? Or is there some type of biologic pathogen? There are many case reports of these individuals, drowning individuals who've drowned in a ditch or other dirty bodies of water developing typically fungimia and dying from that. Another exception to the rule, we go back to traditional CPR. The majority of drowning deaths are from respiratory arrest hypoxia. So this is ABCs where we focus on the ventilation. Obviously good CPR is needed, but you focus on the ventilation because that is typically the primary cause. And unless you suspect trauma, they've removed the recommendation for C-precautions. So unless the individual is known to have dove into a lake or a pool and not surfaced, worried about C-spine injury, you do not need to worry about C-spine precautions. Less than a very small percentage, less than 1% of these individuals will have C-spine trauma. Get them out of their wet clothing. All individuals should be given supplemental oxygen to maintain their SAT better than 94%. Beta 2 agonists may be helpful. And anyone who is symptomatic needs to be admitted to the hospital. Get watched in the emergency department four to six hours. Anybody who's symptomatic needs to be admitted. And if they have diffuse pulmonary findings, they should go to the ICU because these individuals can rapidly decompensate. So if you're on the receiving end in the ICU and you're like, his vitals are stable. His oxygen's okay. He's only on a nasal cannula. Why do I need to accept this patient? Because they decompensate rapidly. So if they've got diffuse pulmonary findings, please accept them to the ICU. There is a lung classification system for drowning. I'm not sure that it's terribly helpful, especially since five and six are respiratory and cardiac arrest, where there may or may not be a problem with the lungs. If the individual had an MI while they were swimming, that may not be a lung problem at all. Any organ system can be affected during a drowning event. The two that I want to point out is cardiac. Sometimes the initial event could be a dysrhythmia or prolonged QT syndrome. You will, if you have an individual who comes to your ICU after a non-fatal drowning event, and they don't really have a good explanation, they're relatively healthy. They're a good swimmer. They drowned in three or four foot of water where they could have just stood up. You really need to focus on looking for underlying cardiac cause. The other thing to keep in mind is in the individuals who are typically trying to commit suicide, who jump from high heights, they may have multi-system trauma. In the United States, the number one location to jump and attempt to kill yourself, and usually you succeed, is off the Golden Gate Bridge. The Golden Gate Bridge has had so many drumpers over the years that they finally have started putting out the safety net, which was supposed to have been completed, is now set to be completed this year. I don't know if it has, but to try and keep these several thousand individuals have jumped to their death off that bridge. This just came out about the recommendations for ventilation, that if you have the need for increased PEEP and oxygen, they're now recommending leaving the settings for about 48 hours. Do not try to wean these individuals. I know we're so focused on getting people off the ventilator sooner rather than later, but in the drowning individual, there's suggestion to leave them at that whatever max PEEP that they required for about 48 hours to allow the surfactant to regenerate. That probably won't be on the test, but it's more for practical. The World Health Organization has finally classified a framework for non-fetal drowning. This is really just to help them gather more data to determine what is the extent of the problem, and we know it's quite large. I just wanted to summarize a few things about drowning, because there is a lot to remember. If you look for the medical cause, especially that QT prolongation, there is no role for steroids or antibiotics initially in these patients. There's no good early predictors for how neurologic outcome is going to go, so this truly is a wait-and-see, and the majority of drownings are felt to be preventable. So CPR knowledge, everyone should know how to do CPR, but specifically if these people have a pool, everyone should know. And if you're letting your child go swim in your neighbor's pool, you want to make sure that whatever adult is going to be monitoring your kid knows how to do CPR to prevent potential tragedy. Last question, which of the following is correct about diving-related injury? One, decompression sickness from nitrogen bubbles is typically present within the first few minutes after a dive. Two, stroke-like symptoms from cerebral embolization is the most common presentation of an arterial gas embolism. Three, it is safe to fly the same day as a shallow dive of less than 30 feet in depth. Four, pneumothorax is a common result of barotrauma. There's over 9 million scuba divers in the U.S. The good news is that there's a very low rate of dive injuries, only about a thousand a year. The bad news is a significant percent of them, 10% of these injuries are fatal. Barotrauma is the most common. It's when you have an air-filled body space, does not equalize pressure with the environment. You can have problems either on descent from under-pressurization, known as squeeze, or on ascent from over-pressurization, and that's where you get tissue rupture, disruption, and rupture, and those are typically more severe where patients get into trouble. Some key points to ask these individuals or the friends that are with them, how long was their dive, what was the dive depth, were they at sea level when this occurred, or were they at a high lake, you know, a thousand, 5,000 feet up, what was their ascent rate, and did they fly post-dive, so some specific questions directly to dive-related injuries. When you're at depth, you can have problems with either nitrogen narcosis or oxygen toxicity. Both of them will cause altered mental status. You can have nausea, vomiting, confusion, and seizure. Obviously, neither of those things are good at depth. Treatment is slow ascent, so hopefully you're diving with a buddy, as is always recommended. Your buddy is there to make sure that you come up slowly, and if you know that you're going to be diving at depth, it's recommended that you have the appropriate gas mixture for that depth, so you want to dive with someone who is experienced. The barotrauma on ascent, as we mentioned before, is the gas expansion on ascent, and blocked eustachian tube is a very common cause of these issues. You get pain, you get rupture, you develop vertigo, you may start to vomit, probably not a good thing with a mask and a regulator in. The other main problem is in your pulmonary function, people will have breath holding. It can lead to shortness of breath, chest pain, hemoptysis, and because of the change in pressure, they can develop subcutaneous emphysema, pneumo-mediastinum, and pneumothorax. Treatment is going to be oxygen, and if it's a large pneumothorax, placing a chest tube. The gas embolism occurs during ascent or immediately after ascent within the first few minutes, and you have expanding gas rupture of the alveoli. Air then can enter your pulmonary venous circulation, goes to your left heart, and your systemic circulation. Cerebral embolism is the most common, and this is when you develop those sudden stroke-like symptoms, seizures, confusion. You can also have coronary artery embolization of gas, leading to acute ischemia. Treatment is 100% oxygen fluid, keeping them subpotent, and getting them to a dive chamber. Decompression sickness, we'll all think of as the bends, this is from the nitrogen gas. Symptoms usually start more than 10 minutes after being out of the, off the dive. Type one is the common, the bends, what we, we think about. Typically, shoulder pain is the most common joint involved. There is a type two, where your CNS is involved, you get headache, ultramental status, could even lead to paralysis. The good news is, is regardless of what the problem is, the treatment is the same, 100% oxygen, keeping them supine, giving them a IV fluids, and getting them to a dive chamber. I know that was a lot of information, and I thank you for your attention. A couple of key reminders, the way to save your patients with heat stroke is identify them quickly, and rapidly cool them down to about 102 degrees. For your hypothermic patients, no one is dead until they are warm and dead. Burn injury patients, if you're not at a burn center, consider transfer for those reasons that we talked about. If there's an associated inhalation injury, or they were present in a fire, you must consider carbon monoxide and cyanide. Electric injury, especially that DC injury, the external injury may be misleading. Drowning patients, it's ABCs, and the time to wean and leave them on for a longer bit of time is the current recommendation. If you have problems with diving, 100% oxygen, fluid, supine, and hyperbarics. Thank you for your attention.

Dr. Heather Lee Bailey

environmental causes of trouble

heat stroke

cold injury

burns

electricity-related injury

water-related injury

diving-related injury