I've been deployed three times, and I'm going to tell you about blast injury. And this is a picture from a CH-47, it's one of those helicopters with two blades on the front and back. You can go any direction, travel on the ground or in the air. And I learned everything I know about blast injury in Afghanistan. I've been to Iraq once and Afghanistan twice, and I've seen a lot of injuries. I'm going to show some graphic pictures because it's necessary to get the point across. If that will disturb you, then I would recommend that you don't stay. So this is what really brought this home. This is the Boston Marathon, the scene at the Boston Marathon. And this is an everyday event or has been an everyday event in places like Iraq and Afghanistan. Everybody thought, well, that's 6,000 miles away, I'm not going to worry about it. But then it happened at home. And it means that this could happen anywhere in the United States at any time. We were completely unprepared for this. Boston is one of our most technologically advanced cities, one of the most modern cities, and this event occurred and nobody was ready. And this was actually, you've heard two speakers talk to you about stop the bleed. This is what caused us to do stop the bleed. Because people were literally bleeding to death in the streets and nobody had any of the equipment or knowledge to know what to do about it. And this really changed our thinking. And I think one thing to take forward, and I realized this about six months to a year ago, is we've always talked about EMS as the first responders. We in the room and every human on this planet are the real first responders. And we need to teach those first responders how to take care of patients. In this scene, so look at these people wandering around, there's people bleeding to death in the street. What are the other people doing? They're just milling around. Why aren't they taking care of these, why aren't the capable people who are walking around taking care of the injured people, which is exactly what they should be. And this is the kind of scenario that a blast or an explosive injury produces. So this, what you see here is multiple explosions. And I saw this when I was in Iraq in 2005. It happened in a place called Mosul. And there was an area, there was a fair going on, there was literally thousands of people just, you know, peacefully buying stuff. And what happened was there was a series of three bombs. So the first bomb goes off, and then everybody comes to help. And then about 10 to 15 minutes later, they're perfectly timed, so now the second bomb goes off. And then more people come, and then 10 or 15 minutes later, a third bomb goes off. And you have maximum killing and injuries. And that single episode produced 238 casualties that we had to spread throughout Iraq to take care of them all, because that overwhelmed all the combat surpluses in the region. And the exact same thing happened at the Boston Marathon, where they had timed bombs located very closely. So I'm going to talk about the epidemiology of blast injury classification, the effects, a little bit about open air versus closed space. I've got Mauricio Lynn has been sitting here very quietly. Mauricio's from Israel, and he has had more experience with this than anybody in the room, probably by far. I'm going to talk a little bit about amputation, and I'm going to talk about brain injury. So what is the epidemiology? So just during the war in Iraq alone, there were 30,000 U.S. and coalition forces injuries. 30,000 people injured by blast injury during the war in Iraq. It's unbelievable. That was U.S. and coalition. Over 100,000 Iraqis were injured by blast injury during that single war. There were 14,000, 14,000 terrorist attacks in 2007 alone. Greater than 44,000 people were injured, and greater than 22,000 dead. And this is a very important point. Half the people who were injured were dead. So the killing potential of blast injuries, not only on a massive scale, but enormously effective. So this is data. This is from the early 2000s. This is when the terrorist attacks really started to increase. Okay, so what are we looking at? So the bottom green dotted line is the number of incidents. That's how many incidents occurred. Single instances of blast-related trauma. And what you see here above that in blue is the number of deaths, and you see that line goes up much more quickly than the incidents, which means that the power of the blasts are increasing and you're killing more people. But look at the number of people that are injured. An incredible, almost an exponential increase in the number of people that are injured because the sophistication of the types of ways that these blast injuries are occurring has increased immensely. And I'll talk about how that happens. So these are the rate of explosion injuries in modern war. So this has obviously been going on, but what I want you to take a look at here, if you look at World War II, Korea, Vietnam, and the global wars on terror, which include both Iraq and Afghanistan, what you see is the number of explosive injuries in these wars has gradually increased. And in the most recent wars, more than three-fourths of all trauma related to injury was related to blast injury. More than three-fourths. And if you look at small arms, so these are people just shooting each other with AKs or M16s, that number is decreasing. So people are getting away from just shooting each other with guns to using explosive injuries because the killing potential is so much greater. So this is just an example during Iraq. What you see here is if you look at overall 4,000 casualties and you divide them into force, you can see that initially in the beginning of the war, in the first 1,000 injuries, only about 20% were explosion related. And then as you get to the second 1,040%, when you get to the third 1,050%, and then almost 60% by the end of the war, which means that people were learning technology, learning how to use explosive bombs, and using it much more commonly because of their potential. So just talking now about the physiology of blast injury, there are really five types of blast injury. Five types. The first type is the primary blast injury. This is the wave created by the blast, and what it is is a pressure wave. So that's a pressure wave that is distributed to the body and causes direct injury to the body by change in pressure, change in the atmospheric pressure. Secondary blast injury relates to the projectiles that are produced. So you blow something up, there are massive numbers of projectiles that are produced that damage the body. And this is what causes the actual amputations that I'll show you. Tertiary injury is a blunt trauma type injury. Okay, so you blow something up, and either a wall falls on you, or that blast wave pushes you against a blunt object. And the blunt trauma that occurs with that is the tertiary blast. Quaternary injury, the fourth type, are other explosion related injuries, illnesses or disease. These are burns, toxic gases that are released from the explosion that cause inhalational injury and those types of injury. Finally, the quinary type of injury are related to other things that are placed within the bomb. So our enemies hate us so much, they'll put stool, human stool, in a bomb so that when a projectile hits you, it will not only injure you, it will also cause bacterial contamination and necrotizing fasciitis. We put nails in there, stool, and then the most thing that we fear the greatest is radiation and the so-called dirty bomb. So imagine the killing effect of these types of weapons. This is why everybody needs to know about it. So this is the blast wave. This is the primary blast injury. What it is, is an almost infinite increase, sudden increase in pressure. And that blast wave travels radially from the bomb and will disrupt anything in its path. It decays over time, and there's actually after that, there's a little bit of a negative pressure that occurs. And if you look at pictures of something that's subjected to a blast, you'll see it's pushed away and then it gets sucked back in. And that's that negative pressure wave that follows the initial blast wave. So what are the primary effects? The things that are affected the most by the blast wave are where there are solid or fluid to air interfaces. So the best example of that is your eardrum. Another example is your lungs, and then intestines that contain air in them. Those are what are primarily effective. So if you have a two PSI shift, you'll hear it. If it gets to five, it may actually rupture your eardrum. If it gets to 15, then there's a 50% chance. And as you see, as it gets up to about 100 to 120 PSI, you get to a slight chance of death. And then the risk of death increases, and when you get up to about 200 to 250, you're probably going to die. So the closer you are to that blast and the more powerful, the more likely that you'll be killed by that blast. Now the secondary blast effects, of course, are occurring from fragments. You heard in the lecture about penetrating trauma, the kinetic injury of a blast effect with a projectile, the energy is equal to one half MV squared. So the most important aspect of that is the velocity, because that's exponentially increased. So you have shrapnel that blows up. It's traveling at a very high velocity and imparts a tremendous amount of energy to the human body, produces the injuries that you've seen in terms of amputation, et cetera. So this is if you have an open space detonation. So it's very, very important to differentiate between open space and closed space. The closed space detonation has much greater killing capacity because the blast is contained within a space and focused on the things that are inside that space, whereas in an open space injury, it's spread out radially over time and decreases in strength as you get farther away from it. So if you're 50 feet away from ground zero and there's a 100-kilogram shell explosion, death will occur both from primary blast and fragments. As you get farther away, 50 to 80 feet, death will occur only from fragments, because now the primary blast has decayed. As you get farther away, you get injury from fragments and then fragments and blast injury, and then the farther away you get out to as far as 1,800 feet, you'll only have injury from fragments alone. So that's the pathophysiology. And these are the safe standoff distances based on pounds of TNT. You can see, again, the closer you are, the more likely you are to get injured. The farther away you are, the less likely you are to be injured. Okay, so one of the most effective ways to injure people is to use what's called a vehicle-borne innovative explosive device. You load up a car, a van, a truck, and with explosive devices, you park that truck somewhere and you blow it up. And one way that this is done very effectively is you place a bomb in there that's activated by a cell phone. You can actually have a bomb someplace and you could be anywhere in the world and you call that cell phone and the thing blows up. So what we did with this in Iraq and Afghanistan is every once in a while, we would activate all the cell phones in the region and terrorists would be planting bombs and they'd get blown up. So there were parts of terrorists lying all around Iraq and Afghanistan because we would blow up their devices. The other way they do this is with radio transmitter. Our Humvees and MRAPs, which I'll show you later, can actually disrupt those transmissions. So this is like a battle between the terrorists whose technology is increasing and our technology. And it's really quite incredible. But if you load up a semi-trailer with a bomb, you can injure people out to 7,000 feet. That's more than a mile away. So more than a mile of dead people from a semi-trailer load up with explosives. What if you're inside a vehicle? So if you're inside a vehicle, the blast wave will not penetrate. The greatest force is actually right outside the vehicle where you have the blast wave hits the vehicle and it bounces off and actually increases in power from that reflection. Now if the vehicle stays intact, you will not be exposed to the blast injury. However, if the impact results in disassembly of the vehicle, then you will be. So that's the critical element. And that's why we went from Humvees, so everybody's seen Humvees, we now have MRAPs. These are mine-resistant, ambush-protected vehicles that have extremely thick hulls. The hull is over a foot thick of metal. And the undersurface is pyramidal, so the blast wave is reflected outward. That pyramidal effect, which deflects the blast wave, though, will allow the vehicle to roll over, which will produce blunt trauma to the victims inside, but not the blast trauma. So if you look at this blast inside a vehicle, look at the Y-axis, very, very little pressure transmitted. You're looking at two to six PSI. In an MRAP, it's zero because of that thick hull. But if you're near the vehicle, again, do that reflection, it'll be up to 600 PSI due to the primary blast and the reflected wave. Okay, so if someone's going to blow up a vehicle, don't stand right outside it. So this is, I would bet that Mauricio recognizes, this is one of the bus explosions, a very common event previously in Israel. This is an example of a devastation of a bomb that you place inside a bus. You can imagine that pretty much everybody in that bus is either going to be dead or badly injured. So just massive devastation, completely destroys the bus. So somebody comes, leaves a package on a bus, either stays on the bus or gets off the bus, thing blows up. Everybody inside is killed. That's a closed space detonation, highly effective. So if you look at this, and I don't know, do you know this guy, Levavitchi? So Mauricio knows this guy. If you look at mortality and injuries related to open space versus closed space, what you see here is, in a closed space detonation, the mortality is almost 50%. In the open space, it's only about 8%. More people, you can see that admissions to the hospital are very close in the closed space to the open area detonations, but that's because in the closed space, you're either dead or going to the hospital with bad injuries. And in the open space, you actually may be uninjured. So closed space, much worse, much more effective killing. And you can see here that open area versus closed space. Open area, predominantly low injury severity scores. Closed space, very high injury severity scores. And you can see, if you look at the types of injuries, open air, primarily eardrum. Remember, the eardrum is the most sensitive to blast injury. But if you look at closed space, primarily lung injuries. And then you start to see bowel injuries and other internal injuries, as well, in the closed space detonations. Now, this is a typical x-ray of a person who's been exposed to a closed space injury. This is ARDS, but it's in a very, very specific pattern. You see, they call this the bat wing pattern. And this is very typical of a closed space injury where you get very, very bad ARDS. And these patients have very high mortality. And this is how it happens. There's actually two mechanisms. First is the overpressure injury. Remember that initial overpressure injury. And what you're looking here is an air, blood vessel, or capillary interface. That primary blast causes the capillary to explode into the alveoli and fills the alveoli with blood, like a pulmonary contusion. The negative pressure causes the alveoli to rupture into the blood vessel, which then causes potentially air embolus and disruption of the alveoli, which causes diffuse air leakage from the alveoli. And you can see this. You have alveolar rupture. It can cause subq emphysema, pneumothorax, air embolism, pneumopericardium. You get air everywhere in the chest. So you'll feel these people, and they'll feel like Rice Krispies. How many have felt that in people? So almost everybody. That's interesting. OK, so how do you manage this? Primary blast injury to the lung. It's supportive. We have no actual real good therapies. Limiting fluid administration is very important. Lung protective strategies using ARDSnet, so small tidal volumes, also very important. It also appears that using neuromuscular blockade and proning result in improved survival. Alternative modes of ventilation, including APRV and high frequency oscillation, may be helpful. Now, in the end, what these patients actually may need is ECMO. But this needs to be done cautiously due to the risk of bleeding from those disrupted capillaries. Because with ECMO, you're generally going to anticoagulate the patient. And they get terrible coagulopathies, and this can cause more bleeding from the chest. The long-term prognosis, if they survive the initial period, is actually pretty good. So this is this MRAP that I was talking about. These showed up in about 2010 in Afghanistan. Again, extremely thick hull. Cannot be penetrated unless by extremely high power blast. And that undersurface with the pyramidal surface that deflects the blast injury. And basically, we went from Humvees, which were worthless vehicles, they would just blow up and everybody would be killed in them, to these MRAPs. And this really caused much higher survival. But again, within these MRAPs, they can roll over. You start to get blunt injuries. You start seeing spine fractures and other intra-abdominal injuries. And, you know, again, you have axial loads, long bone fractures, pelvic fractures, et cetera, in these types of vehicles. So I'm just showing you this data here. You know, the operational tempo of the wars in Iraq and Afghanistan would change over time. In Afghanistan, the busiest period was the summer of 2010. And what you can see here is if you look at total U.S. wounded due to blast-types injuries, you can see that this would increase the total wounded would be as many as 186 in a month. And there was a lot of operational tempo going on in southern Afghanistan. We had our Marines there. And you see these spikes in Marines injured. These people, the Marines, would conquer an area. And then during the night, the Afghans would take it back and they would fill the area with bombs and IEDs. And you'd see these types of injuries and terrible, horrible amputations. And this is a... Every picture I'm going to show you here is a patient I took care of. This is an injured Marine. This is a typical amputation. You see both extremities amputated. There's dirt in the wounds. You can see that the patient has an external fixer. They have a pelvic fracture. And you can see they've had a laparotomy. And they get horrible perineal wounds, intra-abdominal rectal and colon injuries, bladder injuries, et cetera. It is not atypical for their testicles to be blown off. So what Marines and soldiers would typically do, you heard the tourniquet lecture, they would loosely apply four tourniquets, one on each extremity. And if one of their extremities or two of their extremities were blown off, they would simply tighten the tourniquet to that extremity. These war fighters would donate sperm prior to going to war because they knew that they might lose their testicles and they still wanted to have children. They had their blood types actually tattooed on their bodies and on their underwear in every location. So these people went to war knowing that this might happen to them. It was commonly understood when you went to war that this is how you might end up. And you can see here the amputation rates, again, in 2010, gradually increasing. Operational tempo in Afghanistan, particularly, was highest in the summers. And during the winter, there'd be very little battle going on. Everything would stop. It's been that way ever since Alexander the Great was there. That's how it's been in Afghanistan. So, again, this is evidence of the increased wounding capacity of these explosive weapons. You can see in September 2010, more than two-thirds of the injuries were single amputations. But as you go to December 2010, you can see that patients were generally having more than one amputation. Went from one amputation to two to three amputations in single patients routinely. And these are the numbers of GU injuries. This mirrors the bilateral amputations and multiple amputations. Again, testicular injuries from explosive injuries. We developed different types of uniforms and protective equipment that could sometimes help with this, but it wasn't really that effective. So how do you manage a patient with an acute amputation? The goal is to maintain maximum limb length and function. So the initial debridement must be all abnormal dead tissue must be removed, but this may be done in a pattern that preserves tissue in non-anatomic ways. So preserve as much skin as possible, as much muscle and bone. Debride all the dead tissues, meticulous debridement of devitalized tissue. And the other part of this is that the explosion will bury shrapnel and dirt deep in the wound into areas that don't appear to be injured. So when I would debride these patients in the second and third debridements, I would commonly find dirt in areas that look normal. So you have to actually explore beyond what looks abnormal and then pull out all this dirt. Otherwise, they'll get terrible, horrible infections. And again, copious lavage, debriding. The lavage is done without pulsatile lavage. It's done by gravity alone because if you use pulsatile lavage, you can actually injure tissue and drive foreign bodies further up into the extremity. And this is things that we learned from doing this over and over again. So you ligate vascular structures proximal to the bone and separate from the nerves. Never, ever close an amputation primarily. And this is a very important concept. We never, ever close. In fact, we never even put a wound vac on the first debridement. The reason being is even if you completely debride a wound completely successfully, you have apoptosis or programmed cell death that occurs. And the next debridement, which must occur within 12 to 24 hours, you'll find more dead tissue. And this will go on for two or three debridements. And then you only place the wound vac after, say, the third debridement when you see no more dead tissue because the tissue is ongoing dead. In fact, tissue that looks alive is actually dead. You just can't see it. So you have to go back multiple times and do this. Use skin traction. Otherwise, if you don't use skin traction, the skin retracts, soft, dry dressings, and negative pressure wound therapy only after the last debridement does not bring you further death of tissue. So this is something that's very interesting. This is a protocol that was developed at Landstuhl in Germany. So all soldiers evacuated, soldiers and war fighters evacuated from the Mideast, Afghanistan, Iraq, wherever, went through Landstuhl. Big US hospital in Germany. And what they would do is when these soldiers arrived, they would typically arrive within three to four days of injury, sometimes sooner, two days. And they would always take these patients back. And what happened is you have a C-17 with this huge plane that would deliver up to four ICU patients from Afghanistan, 10-hour flight, and 40 walking wounded. And so you get this bolus of patients. They come in a school bus, and they deliver them to, you imagine, 44 patients at once delivered to you. And invariably, some of these would have amputations. And what you did is you took them to the operating room, and you biopsied the tissue, routinely biopsied the tissue. You sent three pieces of muscle. And you would get pathology back within 24 hours. And you looked for fungal elements. Because the worst infections were caused by fungal elements, which actually live in the dirt in Afghanistan, and had gotten worse over time as our antibiotic therapy cleared out bacteria that were helpful. And if you saw fungal elements, you treated with broad-spectrum fungal therapy, including Vorconazole, Amphotericin B, routinely done on all people coming back from Germany. This is an example of another wounded warfighter, again, testicular injuries, bowel injuries, colostomy. And you can see very, very high amputation. Now, these amputations didn't start like this. They were much lower. But due to ongoing cellular death and infection, it was necessary to breathe this all the way back to the hips. And what would typically happen in these types of patients, the infections would continue, and they would approach the torso, and then the patient would invariably die. It's very, very, very sad. These are awake, talking people. So, you know, typically, if somebody developed these types of amputations in Iraq or Afghanistan, we'd basically intubate them, put them to sleep, so that they'd wake up in Germany and not have to suffer from what they were doing until they had greater support. Okay? Traumatic brain injury. So this is also very important. So there were mandatory command evaluations. If a service member was in a vehicle associated with a blast, a rollover, a collision, they underwent assessment of their brain. Or if they had a direct blow or loss of consciousness. So they would be routinely evaluated. And the assessment was very, very simple. Do they have headaches, ringing in the ears, amnesia or altered consciousness, double vision? Or they're just asked, do you seem okay? Does everything seem okay? So if they had this early on in theater, they would get a mandatory CT. Later, they would get MRIs. They brought MRIs in theater to assess brain injury. If they had a brain injury, they had a 24-hour rest period. If this recurred recurrently, they would go to one-week rest periods. And if it happened a third time, they'd be sent home. It's very, very much like the NFL, right? Well, guess where the NFL got this from? They got this from injured war fighters. That's where they got it from. So very, very interesting. So in terms of delayed tissue injury, it was very important in these patients that they might have seemed to be okay originally, but with delayed injury, they would do a pan scan looking for delayed injuries. They typically had head and bowel injuries and extremities, looking for fragments in the extremities. Now, this is what I was talking about, this apoptosis. So apoptosis is programmed cell death, and it appears that blast injury that's distributed to human tissue causes immediate death, but then delayed death of tissues. That's why you have to do repeated debridements and delayed CT scans of the head. And I took care of two soldiers myself who were absolutely normal after they were exposed to a blast. Their brains were completely normal. Normal head CT, top left. Put them on planes, and when they got back to Germany, they were brain dead. They developed diffuse swelling. Again, apoptosis, brain death. And this is terrifying because you couldn't predict it. When you saw them, they had a normal head CT. They're sitting up and eating and talking to you. They got to Germany, they were dead, and there was no way to predict this. Here's the example in an extremity wound. And here you can see this patient's had multiple debridements, still having tissue death, still having infections. What about PTSD? PTSD is very, very hard to predict after blast injury. People with PTSD look almost identical to people without PTSD, with the one exception being that blast lung injury has a greater association with PTSD than any other injury in this study. So it's actually very, very interesting. So this is very, very complicated. This basically tells you how do you manage a patient with a blast injury. If they have external signs of trauma, you manage them like any other trauma patient. A full head-to-toe evaluation, primary survey, secondary survey, PAN scan, in most cases, again, due to missed injuries and delayed injuries. The ones that are the tough ones are the ones that have no external signs of injury. And these require very careful examinations. They all need chest X-rays. They all need pelvic films. You're looking for blast injury of the lung. Again, if you don't have lung injury and you don't have extremity injury, the patient will probably be okay. But you must, again, evaluate them within 24 to 48 hours, again, due to delayed injuries. And that's all I have. So bottom line, the incidence is increasing. We all need to be aware of these problems. We will, if we practice medicine for any length of time, we will be exposed to these patients. We will have to take care of them. The effects are devastating and diffuse. Multi-amputations is typical in these types of injuries. And the delayed tissue injury concept is really a new concept that we need to learn how to deal with. Thank you.

blast injuries

former military member

preparedness

first responders

types of blast injuries

acute amputations