My name is Tony Alamo, this is Bob Sanders and our session today is about hyperbaric medicine and applications that might keep your employees working with hyperbaric oxygen therapy. We have no relevant financial disclosures, Bob works at NASA, I work at a hospital in Memphis called Regional One. So our objectives for this hour is going to be describe the indications for the use of hyperbaric medicine, and we're not going to discuss all of them, but we're going to discuss probably the ones that you may be more, may come across more. We'll discuss conditions that will benefit workers that may be injured on the job, and we'll discuss treatment of conditions related to aging, diabetic foot wounds, vascular disease, etc. Think of us as colleagues, and ultimately we don't want you to think of us as witch doctors practicing voodoo medicine. We're actually going to be talking about evidence-based medicine throughout this conference, throughout this lecture, and about the science behind hyperbaric. So not only do you understand where it can help you and help your patients, but you'll understand why and how, and that is our goal. But before I talk to you about, we talk to you about what hyperbarics is, we should talk to you about what it's not. It is not something that you're going to go buy in a store in a can or in a bottle, and these are all commercially available products that sell the benefits of extra oxygen. You can buy it in a can, you can buy it in a bottle. You can go down the street in Las Vegas, and virtually every hotel you stay at is going to have an oxygen bar, where they let you breathe flavored oxygens, and they tout the benefits of it, but there's no evidence, no science, no benefit to situations, oxygen bars. Topical hyperbaric oxygen is something that's out there. Early on in my career, I had a vendor come and present this to me and say, hey, this is evidence-based medicine. Look, I have studies that show the wound, that this improves wound healing. I said, all right, great, I'll be open-minded, I'll read your study. So I read it, not overly impressive, but it did have a good p-value. So then I decided to look up another item that cost much less than this. Maybe you've heard of it, kind of a rare item called the Band-Aid. Well the Band-Aid showed almost identical, if not slightly better, science behind it and evidence in improved healing. So again, not only do we have to accept the evidence that's out there, but we have to question it and make sure we know we're making the right comparisons as we move forward. As an occupational health physician, you're definitely a targeted, we are targets for an industry that's out there, what is being called mild hyperbaric therapy, or mild oxygen therapy, mild pressure therapy. I'll tell you that this is FDA-approved therapy, and indeed it is. But it's FDA-approved for one indication, and that's acute mountain sickness, high-altitude pulmonary edema, high-altitude cerebral edema. Now how many of us, I'm from Houston, so how many of us actually treat high-altitude pulmonary edema in our regular practices? No one? Exactly. By the way, the brand name Gamow bag costs about $3,000 to buy a brand name item. These run about $12,000 to $18,000 for basically a very expensive Gamow bag. So we've talked about what it's not, now let's focus on why we're here, and that's to learn what hyperbarics is. And hyperbarics is evidence-based medicine for 16 UHMS, our National Medical Society, UHMS-approved indications, and Medicare follows UHMS. It's defined as the administration of 100% oxygen intermittently at pressures greater than sea level. And the science behind it really shows there is a threshold where we really need to hit about 1.4 atmospheres absolute, or 1.4 times the pressure that's on us out here. It's a new application of an old technology. In fact, hyperbarics goes way back to the late 1800s, early 1900s when we had caisson workers, or bridge builders, and tunnel diggers that were having a fatality rate. Can you imagine being in an industry as an occupational doc where 25% of your workers are going to die on the job? That's the risk that bridge builders, that caisson workers had in the late 1800s. It wasn't until around that time that an individual, an engineer, not even a doctor, because the doctors considered hyperbarics as voodoo medicine, an engineer said, well, maybe we should try this, maybe we should recompress them, maybe we should bring them up slowly. And that engineer, that occupational medicine thought, changed the death rate, the mortality rate in that industry from 25% down to about 3%. And in fact, in the three years after he instituted the process of decompressing as they came up, he had only one fatality in the following three years. Hyperbaric medicine can be elective or emergent, and we'll talk a little bit about that. Much like with diving, and we'll go into these in more detail, it would be the primary treatment modality. But for much of the time, we're actually an adjunctive therapy. We team up with the docs that are out there. We work together to improve outcomes. And isn't that our goal, to improve our patients' outcomes? Whether it's an injury that happened on the job under our watch, whether it's a patient that just came to us due to an occupational injury, or whether it's someone's underlying health issues that are becoming more and more prominent in society today that impact our workers and put them at risk on the job. Typical indications, just to give you kind of the big picture, we're not going to go over a list quite yet. We'll treat toxicologic emergencies, infectious issues, traumatic emergencies, vascular and hypoxic injuries and illnesses, utilizing evidence-based medicine. This is a list of our 16 approved indications. We'll go into it in a lot more detail. I've just color-coded it based on some of the way I'm dividing it up for this lecture. Now I'm going to turn it back over to Tony for a little bit. So how much pressure and how much oxygen? Well, it depends. Depends on the condition that we're treating as to how deep we're going to go. And then the oxygen will also depend on how deep we are. Beyond three atmospheres, you can't use 100% oxygen because you have a problem called oxygen toxicity. So after that, we have to reduce our concentration of oxygen to maybe 50% or some other variation. At our hospital, we use 50-50 mix that we call nitrox, nitrogen and oxygen. Some of the, a lot of the hospitals will use a 33 feet of seawater or two ATA to treat a lot of these conditions, chronic wounds, radionecrosis, et cetera. We choose to treat at the 45 feet of sea level depth, and we have just as good of outcomes realizing that the higher the pressure, the more risk you have of oxygen toxicity. Certain conditions like carbon monoxide poisoning, you have to go deeper such as 2.8 to 3.0 atmospheres to effectively treat those conditions. And then decompression sickness or arterial gas embolus, we treat even deeper than that. We'll go 100, 165 feet of seawater even. There are some treatment tables that go up to 220 feet of seawater, depending on what your diver's been exposed to. Commercial divers, which is where I got into this business, they may dive 500 feet of seawater. You're not going to treat them very much, very effectively if you're only going to 60 feet of seawater. You got to go deeper. So why not give them more oxygen? If a little is good, a lot's better. Well that's not necessarily true. Oxygen is a drug, and just like many other drugs where a little bit is good, and I'll just pick one, let's say fentanyl, a little fentanyl is good, too much will kill you. While too much oxygen will cause problems, the one that we see, or we see most often I guess, is a seizure, but the incidence is only 1 in 10,000. Now I have never had one of my patients have a seizure in the chamber, but it's going to happen sooner or later. The literature tells us that. And the higher concentration of oxygen, or the higher depth, the deeper depths that we're treating at, the deeper we go, the more chance we have of a seizure. If we do a lot of treatments in some of our decompression tables, we will get some pulmonary oxygen toxicity. We give them so much oxygen over a very short period of time that they actually have coughing, will actually affect their pulmonary function tests with oxygen. And you may know this, treating some of your patients in the hospital, even on nasal cannula. But the one thing that we want to make sure, in both cases, both the seizure, it's not a seizure disorder, it's a single episode of seizure, so we're not creating a new illness, it's just a response to the oxygen, we lower the oxygen, the seizure stops, no greater risk later. And likewise, the pulmonary functions changes, this is not a permanent change to pulmonary functions, it's a temporary change, so long as we catch it early enough that we don't cause permanent injury. So you can have up to a 10% decrement, and your patients will heal just fine from that. So how safe is hyperbaric oxygen? It's actually very, very safe. In contraindications, there's only one absolute contraindication, and that's an untreated pneumothorax. Now, most of the time, those, when they come to our department, they've already been treated, they got a chest tube, some kind of decompression already. All the other issues that you may hear about are relative contraindications, and unless you're actually using this, we're not going to go over those today. My hospital has a multi-place chamber that I'm going to show you in one of these slides. On the left here, oops, that wasn't good. On the left here, we have a clear plastic hood that goes over a patient's head, and then this neck ring right here where that hood attaches. That's how they get their oxygen. You can see this guy sitting in a chair, and inside these multi-place chambers, you're always going to have an attendant, and that attendant will regulate the flow of oxygen, and in the event of having a problem like a seizure, that's where your help is. Our chamber holds 12 people. The other thing that you can have, most of the hospitals will have this mono-place chamber. This is one brand, Sechrist, and there's advantages and disadvantages to each one. The mono-place chambers, they're very cheap, relatively speaking, to get into. You can buy a used one for, say, $80,000, but a new one will cost you maybe $200,000, whereas a multi-place chamber will cost you maybe a million or more. In terms of the facility, you can put a mono-place chamber anywhere. You can put it in your office, but a multi-place chamber, number one, you have to have a special foundation to even support the weight of this chamber. I mean, it's tons of weight, and then there's a lot of other fire requirements, NFPA requirements that you have to follow. Staffing, you only need one tech to run a mono-place, while you have to have at least three people to run a multi-place, because you have to have somebody in the chamber, somebody running the console. You have to have a backup just in case we have a problem, and then you have to have a physician. And in terms of cost, I guess, overall, the cost of the mono-place is much cheaper, I guess, per treatment. But some places say if you fill up your multi-place, let's say with 10 people, and keep that running pretty good, then it's actually better for your hospital. In terms of differences, the mono-place, it's filled with oxygen. You're pressurizing this tube, this acrylic tube, with oxygen, and that's how you get your pressure. In the multi-place chamber, you're pressurizing with air, and then you're giving them oxygen through this head tent. In the mono-place chamber, there's a special mask that you have to have to get the air, whereas in the multi-place chamber, you got air all around you, all you have to do is take off that head tent, and you're breathing air. In the mono-place chamber, obviously, there's only one person, except when we're treating kids, we might have mom or dad in there with the kid. And then in the multi-place, you're also going to have a staff member, at least one in there with you. Critical care, we have the ability to do critical care in our hospital. It's much easier to do a ventilator and attend to that ventilator patient inside of a multi-place, but a mono-place, there's probably maybe only two places in the country that are really equipped to do critical care, running a ventilator patient inside of a mono-place chamber. Let me give you this case report that I treated, actually, not long after I got to Memphis about three years ago. This is a gentleman, 54 years old, who had a mass in his throat. He was diagnosed with carcinoma of the vocal cords. He was treated with surgery and radiation in June to July of 2020, right after COVID started. Shortly after he had his radiation, he had trouble speaking. He kept on working until Thanksgiving of that year. After that, he had so much swelling in his vocal cords that he had to get a tracheostomy. Not long after that, his physician sent him to us saying, you need some hyperbaric oxygen therapy. The only thing this guy wanted was to get back to work. I just love those kind of people. When he first came in, he was coughing up the secretions. We had one of those vomitous bags. He would spit into this bag just constantly almost. After about 10 treatments, he lost the bag and his coughing was almost non-existent. He started breathing much more easy through his tracheostomy because he didn't have all those secretions. After 30 treatments, he was able to get his tracheostomy removed and return to work. One of the conditions that we treat is called radiation necrosis. Radiation is wonderful. It gets rid of a lot of cancers. Unfortunately, in about 3% to 5%, we have problems related to that radiation. That's when they come to see us. Radiation works by damaging the blood supply to these cancers. Well, it's going to hit some normal tissues too. About six months to maybe several years after exposure, they could have some symptoms. Hyperbaric oxygen will actually grow blood vessels into areas that are hypoxic and able to heal the tissue. We can see this radiation problems in brain and spinal tissue. I know you've probably heard of St. Jude. St. Jude treats kids with cancer. We treat St. Jude patients with their radionecrosis of the brain. Generally, to get some of these, the level of radiation that you get, radionecrosis is 3,000 to 5,000 rads. Turn it back over to Dr. Sanders. Now, let's start talking about the hows and whys of hyperbarics. Dr. Aleman gave a really nice case of late effects of radiation. We talked about the effects on the cells on the blood flow. When you have these tissues, you can get very hypoxic tissue. What we're looking here is just a cartoon, if you will, of regular tissue that's been irradiated, post-irradiation, very hypoxic, five millimeters of mercury. 40 is what we consider a normal tissue oxygen tension. Now we have this hypoxic tissue, doesn't do well. Our cells need oxygen to live. In fact, our body is probably designed for something more like 24% oxygen in the environment. We survive on 21. That's okay. We do just fine. But once you start lowering the oxygen down enough, our cells, in a sense, will go into hibernation where we just don't have the capability to heal, to do the extra procedures that are necessary with the wound healing and the wound repair. Under hyperbaric conditions, when we're breathing oxygen, and we'll talk more about this, we can get those tissue tensions in the hypoxic area right up to 50. So that's above that normal level that we talked about needing for wound healing. So during the time the patients are under pressure, the cells are starting to wake up again and heal. But actually, in the healthy tissues, we can get it much, much higher. We create a very steep oxygen gradient. This is something that our body recognizes, and it recognizes quite well. And it actually responds to that. And what we actually see is vasogenic stem cell mobilization, so angiogenesis. That's what Dr. Alleman talked about when he said, building new blood vessels in hypoxic tissue. When we get that steep gradient, and we get a cycling of that steep gradient, you get your treatment, 90 minutes, you get the high oxygen, then you go back to hypoxic. And that day in, day out, hyperoxic, hypoxic, hyperoxic, hypoxic, makes the body realize we have injured tissue. So now it's going to mobilize vasogenic stem cells, stem cells into those hypoxic areas to build the new roadways, the new pathways, so we can bring in the heavy machinery to rebuild the tissue. We get vasogenic stem cells. We get neovascularization. And this is some work that Dr. Tom did in Maryland, and in his time when he was actually here in Philadelphia, where we can see just with one treatment, after one treatment, we start to see the mobilization of stem cells. And then after just a few treatments, we can get up to eight times the number of vasogenic stem cells, after only 20 treatments, eight times the number of stem cells that would be there nominally to help the tissues heal. So we talked about radiation necrosis. What might be another very, very prominent medical problem that many, many of our workers have that will affect blood flow, especially into the distal periphery? Diabetes, exactly. We know that affects blood flow. We know that affects the patency of the blood vessels. We lose the blood flow. We lose the ability to heal. But in addition, the diabetes causes an impairment in stem cell mobilization. That's part of the reason why these wounds that diabetics get are so difficult to heal. We've talked about that. We've shown you the evidence of HBO helping with that stem cell mobilization. And it also improves getting the stem cells to those experimental wounds. Early on in hyperbaric research, they did some nice studies on when you had your medical students. They were your nice volunteers. They had a bunch of medical students where they surgically caused wounds to the hands and really looked at how the hyperbarics can help with that homing in of stem cells to those experimental wounds. Dr. Aleman talked about his case with radiation. One of the real impactful places where we see this is we call it osteoradionecrosis, especially which is radiation injury to the bone and bones of the jaw. And why is the jaw so unique? Well, I think you all have heard of this very, very unique field of medicine called dentistry. And the reality is, having just gone to the dentist last week, virtually every trip to the dentist is traumatic. It is traumatic to the jaw, just getting in there and scraping. God forbid you have to have a filling or even more a root canal or an extraction. These are very, very traumatic issues. And like I said, a radiated tissue has enough oxygen to stay alive, but not enough to heal itself. They really have this podium very close to the edge. And it's an occupational doc. I just, this worries me. So it can't heal itself. So if we take this tissue that's kind of just surviving and cause a significant injury, such as removing a tooth, now when cells and the body has tissue that is injured and it cannot heal it normally, if cells start reproducing abnormally, if they start reproducing without normal controls and growing, what might that be called in layman's terms? Cancer. Exactly. Our body doesn't want that to happen. So it has its own protective mechanism called apoptosis or programmed cell death. So now we have a radiated tissue. And so this is a picture that Dr. Marks did in his studies where you can see all these empty blood vessels in bone. In fact, after radiation, we can get down to somewhere about 5 to 20% of normal vascular flow in irradiated tissue, 20%. Not enough blood flow to heal itself. So the body doesn't want the cells to become cancerous. The body tells the cells to start to die off, apoptosis. Osteoradionecrosis. Now the jaw actually starts to, in a sense, dissolve itself. Now we go and bite in an apple. We eat something. All of the sudden, we're using a lot of force. And the jaw is a bone that's always under force and torque. And we can see pathologic fractures from someone just eating a meal. And this is very, very difficult to heal because now you have injured bone. You can't just put in a plate and screw in a plate. With hyperbaric oxygen therapy, Dr. Marks has shown that we can, now you see all the blood cells in those blood vessels. We can restore that blood flow up to about 80% of native blood flow with just hyperbarics alone. And this is a study looking at tissue oxygen tensions and looking at that elevation, that recovery of blood flow into tissues over time. And again, that 20 seems to be almost a magic number where we really start to get maximal blood flow return. We still have more wound healing, so it is not uncommon to go beyond 20 treatments. But that's a very important first step in therapy. Now, I have just made a lot of claims to you all. This is an evidence-based study. This is an evidence-based program. So it is very fair for you to say, enough Dr. Sanders, show me the evidence. Absolutely, I will show you the evidence. Because that's an important part of any time we approach a new medical therapy that may be new to us, even though it may not be new in society. Delayed radiation injury, we have studies that show we can decrease that programmed cell death, that osteoradionecrosis in Dr. Marks' work, from about 30% of patients down to about 5.4%. Huge, huge improvement. Can you imagine having a jaw break on you just from eating? And we can prevent that from happening with hyperbarics. We talked about diabetics. These are these chronic arterial insufficiencies, chronic problems with blood flow, diabetic lower extremity wounds where you actually have necrotic tissue in the toes and the feet. We can, with hyperbarics, we can actually decrease major amputations from about 33% down to 8.6% in one study. And more importantly for you, for us, as occupational medicine doctors, I say you and I apologize. I'm not board certified in occupational medicine. I'm board certified in underseen hyperbaric medicine as well as emergency medicine, but I practice diving medicine and occupational medicine at NASA. In one double-blind randomized controlled trial, so our gold standard trial, they were able to induce complete healing in about 12 weeks in five of eight patients versus one of eight in the control group. Complete healing. With diabetic foot wounds, it's so important to heal that wound so we can get our employees back to work. I treated a case, I had a case when I was working for the film and television studios. We were filming the movie Godzilla and we were working on a very hot boat deck, a metal boat deck, so they wanted to be able to go on tracks underwater and come back up. And one of our special effects technicians was a diabetic. He sustained a very serious, very deep full thickness burn. He wasn't aware of that. This is a very classic case that could turn very bad in a very short amount of time. But hyperbarics has good evidence behind it showing the benefits in these exact patients, in these diabetic wounds, these non-healing wounds. All right. So what do all of the workers in these pictures have in common? Whether it's a farm worker in Alaska picking berries, a factory worker who is working with a forklift, a propane powered forklift, which, well, if it's propane, it's got to be safe to use in any environment, right? Wrong. It's still an internal combustion engine. Fishermen, astronauts, lawyers, basketball players, construction workers, divers, boat builders, ship builders, construction, other factory workers, even bakers. Those pictures all represent patients that Dr. Aleman and I have successfully treated with hyperbaric oxygen therapy. They represent occupational cases. Some are going to be acute workplace injuries. And this is a different order of our list of indications. Air or gas embolism. Where do we probably see that the most? As physicians. Central line placements in the hospital. We see air embolisms. Bubbles being introduced into the bloodstream. A bubble into the arterial blood flow. Where does a lot of arterial blood like to go? To the brain. What does the brain not like in it? Blockages, bubbles, strokes. Decompression sickness in divers. I know we have several people from the military here. We appreciate your service. Thank you very much. But this is what you're treating. Divers, decompression sickness. Carbon monoxide poisoning. It can happen in unplanned times. We showed you a baker. I actually treated several bakery workers who went unconscious because the flame in their ovens was not working. There was some buildup in some of the burners. And so they only got partial combustion. And they were actually creating carbon monoxide inside their bakery. And this can be with or without cyanide poisoning. In fires, firefighters are frequently exposed to carbon monoxide and cyanide due to the byproducts of combustion of a lot of plastics. Acute thermal burns. Saw that in a worker, in a construction worker building a boat in Los Angeles. You wouldn't expect an acute thermal burn there. But we see thermal burns in workplace injuries all the time. Crush injuries, compartment syndromes. I was in the ER on Sunday and treated a crush injury. Acute blood loss anemia. Well, hopefully we're not seeing that a lot in our patients. But if you do have a bad work-related injury, especially if you have a patient who's got a religious belief against being given blood, we no longer have to sit and watch that patient die because of their religious beliefs. We can offer them a therapy that can help them. And we'll talk more about this in detail a little bit later. Chronic conditions as well. The diabetic foot wounds. Central retinal artery occlusion. Now, hopefully we're not seeing a lot of gas gangrene or necrotizing fasciitis. But that small wound that happened at the workplace can become much worse, especially in some of our compromised patients. Chronic refractory osteomyelitis. A bone infection that's not healing. Responds very well to hyperbarics. Flaps and grafts. Soft tissue radionecrosis we've talked about. And then there are some other indications that I'm not going to go into detail about. But these are chronic conditions that might affect our workers. Sudden hearing loss. Other effects of late radiation issues. Osteoradionecrosis we've already talked about. And intracranial abscess. We really don't see much of that. So these are the ones that we've talked about. We're going to focus on over the last part of this lecture, over the next 20 minutes or so. But I've got to throw some physics at you. Sorry. I know it's been a while. We're going to start simple. We're going to start Boyle's Law. Boyle's Law states that if you increase pressure on a gas, you're going to decrease the volume. Let's put this into perspective here. What does it mean to increase pressure and decrease volume? Now we are going to talk a lot of physics. I hope this doesn't make your head feel this way. But in reality, this is exactly Boyle's Law in action. So we talked about air embolism. We talked about that central line placement failure where we introduce a bubble or a blockage into the brain. If I have a blockage causing a blood flow restriction in my brain, and that blockage is an air blockage, what might be a modality that I can do to affect that blockage and maybe change blood flow past it pretty quickly? Any ideas? Pressure. Boyle's Law. Exactly. Put them in a chamber. I can shrink the size of that embolus down right away. And it's fascinating when you get down there and you actually put some under the pressure and you watch their symptoms resolve. Excellent. I had someone come in. They were paralyzed on the left side. I put them under pressure. I shrink that bubble. They have good movement again. Are we done? Can I bring it back up to the surface and call it a day? No. You're shaking your head. Why not? He's asymptomatic under there, isn't he? But what's going to happen as I come back up? The bubble's going to get bigger. Keep that in mind. Keep that in mind. We talked about hyperbarics for decompression sickness. If I have bubbles, these are nitrogen bubbles, not air bubbles, causing problems in my tissues because I've got a space-occupying lesion where I don't want a space-occupying lesion. A bubble. What might I do to a nitrogen bubble to help my patient's symptoms? Same thing. Put them under pressure. Shrink that bubble. Destabilize the bubble because small bubbles are unstable bubbles. All right. Next. Oops. Sorry. All right. That's not working here. Let's see how I'm going to get my video to play. There we go. All right. The next gas law, Henry's Law. Henry's Law states the solubility of a gas is directly proportional to the pressure on that gas. So I go diving. I might go swimming. So I go diving. My body is like a soda bottle. Soda is carbon dioxide inside a gas. So this is a soda bottle under pressure. You don't see bubbles. But we lower the pressure on that soda. What do we see? Think about a champagne glass as well. If you'd rather drink champagne than unsweetened soda water. I know a lot of us don't like that. I love it. But when we decrease pressure, we decrease solubility of a gas on a liquid. In divers, it comes from diving and absorbing extra gas. But in aviators, just the amount of nitrogen in our body right now, if we go up to altitude and we lose pressure in an aircraft, and if any of you deal with aviators, this is something we need to think about. You can create decompression sickness in your aviators. In the astronauts that I treat, any time they do a spacewalk, if I didn't do something about the nitrogen in their blood, I would bend 100% of my astronauts. And I don't think NASA would hire me if I did that. So we decrease the pressure. We have that ongoing solubility issue, bubbles forming. If bubbles are forming because I've decreased pressure and these bubbles are causing problems, is there something that I can do to stabilize that patient really quickly, really easily, and stop any additional bubble formation and growth? What might that be? Pressure, increasing pressure, exactly. Why I'm up here and lecturing? You guys obviously know it. You want to give the rest of this lecture and I'll sit back and watch? Ah, I have more fun doing it. All right, so right, we can put them under pressure and we stop any bubble formation and growth. And that's fantastic. But if I bring them back up, what's going to happen? Same thing, the bubbles are going to form. So now I need to do something to get that gas out of solution. We'll talk about that. But as we said, we put them under pressure, no new bubble formation and rapid reabsorption of the shrunken bubbles, all is good. This is a stabilizing. Again, I've just said hyperbarics works for undersea medicine issues. Decompression sickness, air embolism. Let me show you the evidence. Don't just let, don't take my word for it. I'm passionate about this, but I'm also a diver. So I must be a little bit crazy at baseline. We have really good studies out there, not randomized controlled trials, because now it would be unethical to withhold treatment. The only trials that would happen now would be comparisons of depths, comparisons of times. But we know this is the gold standard. We know it works. But again, study after study out there shows the benefits of hyperbarics. Now I've talked about the solubility portion of Henry's Law from a stabilizing issue. But now let's talk about it from a treatment issue as well. Not only can I help that nitrogen go back into solution, but now if I breathe pure oxygen, I'm going to denitrogenate the body. Every breath in is pure oxygen. Every breath out is oxygen and nitrogen. I'm going to denitrogenate the body, denitrogenate those bubbles so I can safely come back up and no new bubbles will form. That's awesome. But it goes even further. If I'm breathing that oxygen under pressure, I'm going to get more oxygen into my body, into my tissues. Remember that slide early on that had, that was originally 5 millimeters of mercury in the cell and we got it up to 50? And outside we got it up to 350? Wow, that makes a huge difference. That increased oxygen solubility can actually help the oxygen carry, sorry, the plasma of the blood, which right now is not transporting oxygen. Right now, only our red cells are transporting oxygen pretty much, and what are they saturated to for most of us? 98%, 99? It's not a lot more you could get in there from the hemoglobin. But if the plasma now can carry oxygen, all of the sudden, we can get a lot more oxygen into those tissues that already have blood flow issues. In fact, it goes from .3 volumes percent, whatever that means, I have tried to figure that number out, but that's all right, from .3 to 6, that number I can tell. That's a 20 times increase in the carrying capacity of oxygen by the plasma, 20 times. If I only have one-tenth the amount of blood getting to that wound because it's hypoxic tissue, I am still getting more oxygen to that wounded area. And that's one of the magic things, magic? That's one of the evidence-based things about hyperbaric therapy. In fact, in 1960, a gentleman named Buermo did a study where he believed in this, and he proved it. He took pigs, exsanguinated them under pressure, and let them live with literally nothing but a plasma substitute in their body. They did great. They ran around, brought them back to the surface, put the blood back into them, re-infused them, and then showed there was no neurologic deficits in these pigs. Now, I always wonder, and I've done pig studies, too. You know, how much can we really trust neurologic deficits in pigs? No, we can't. But they also had a lot of bacon and ham after the study, too, so it worked out well for everybody. But they showed the human body, the animal body, can do great. And he wrote to him, his research was titled, Life Without Blood. So now, if we're increasing that oxygen, if we really do a good job, and all of the sudden you've got oxygen in your plasma, just randomness is going to help cells do better. Carbon monoxide poisoning is such a dangerous thing because of that binding of carbon monoxide to hemoglobin, and now your cells aren't getting oxygen because the hemoglobin's not transporting it. Well, with hyperbaric oxygen therapy, we can normalize the oxygenation of the cells. But not only can we do that, we can speed up the off-gassing process, getting that toxin out of your blood. Because now, that random grab and release that happens in any sort of equilibrium in the system, there is so much more oxygen, the odds are the hemoglobin can pick up oxygen before it picks up another carbon monoxide molecule. We can decrease the halftime of the toxin in the system from 320 minutes down to 23 minutes. Very, very beneficial. Now wait, I've heard that hyperbarics is questionable for carbon monoxide. Show me the evidence. Of course, I will. And in fact, with carbon monoxide poisoning, we've seen really good, randomized, sham-controlled, double-blind trials where we've seen a decrease in cognitive sequelae, late effects of carbon monoxide, from about 46.1% down to 25%. Forty-six to 25% long-term injuries. That's huge. That's huge. And in fact, the evidence is very clear. Hyperbarics is effective. The question that the insurance companies want to get out there is, is it more effective or cheaper than ground-level oxygen for the same level of efficacy? So, okay, we're going to have some people that have brain injuries from carbon monoxide. Well, they had to have done something, so that's on them. Are we really going to save the insurance company's money? Now, I'll admit, there are a few studies that show it's equal to ground-level oxygen. There are really good studies that show it's more effective. I just soon get a poison out of my blood as soon as I can. So I'm a huge believer in it and I've seen it work. We use it in fetuses a lot too, in pregnant patients, because it is so effective and we know it can cause neurologic sequelae. And there's really good, when you start to read all of the studies and compare the studies, for those that really do have a good placebo or sham trial or gold standard versus hyperbarics, you'll see that the evidence is there. We also talked about anemia and Vuerma's work with life without blood. Now this isn't something that we can really study very well and cause acute blood loss anemia that would be fatal in patients to show that it works. But if we look at the research out there and the publications that deal with acute blood loss anemia, 35 out of 35 publications that were found in this particular study showed improvement in morbidity and mortality. Hyperoxia. What does it mean to breathe lots of oxygen? Dr. Alleman talked about seizure, talked about pulmonary oxygen toxicity. Why do some of these things happen? Well we know that hyperbaric oxygen causes a local vasoconstriction in healthy tissues. But I've also told you we improve the oxygen carrying capacity of the blood and we actually affect white blood cell stickiness, leukocyte beta integrin adhesion. White blood cells stick to the walls of the blood vessels in hypoxic tissues. It just happens. Beta integrins do this. So now we have hypoxic tissues and we already have blood flow issues there. Now we're going to have white blood cells basically parking their cars on the side of the freeway. How is that going to move with the flow of traffic when we start having all these cars parked on the side of the freeway? We're decreasing blood flow. That's going to worsen hypoxia. But now with the extra oxygen, we're improving the blood flow out. If I can decrease blood flow into an area of tissue but improve the oxygen carrying capacity and then I improve the blood flow of the oxygen, sorry, the blood flow of the tissues going out, what's going to happen to my tissue edema? Edema is going to go down. Hyperbaric oxygen therapy is evidence-based medicine for edematous tissue type problems. We can decrease tissue edema. Compartment syndromes where your only option if you don't use hyperbarics is basically fasciotomy. Talk about a very impactful procedure for our employees to undergo for just getting hit in the arm or hit in the leg. If we can prevent that, that would be huge. And then acute thermal burns are very much an edematous tissue issue as well, as well as infectious. For crushes and compartment syndromes, yes, I'll show you the evidence. We can see improved healing, 94% versus 33% in one study getting complete healing in the work of Bouchard and others. Seventy-five percent cost savings if we can prevent the fasciotomy. I work in a little rural ER in Hallettsville, Texas, Lavaca Medical Center, and it's amazing these different stories. I had a patient was working on changing a tire and the jack fell out from under the car. Her arm got pinned between the tire and the van, only for a short period of time before the tire fell out. But that was enough of a blow to cause a compartment syndrome. We did get her evaced out to a trauma center, and with hyperbarics, actually never needed to have a fasciotomy, got there soon enough. But the work of Paul Cianci and others, work of Dr. Hart, again, time and time show the benefits of burns. And the more severe your burns are, the better the patients do, and the cost savings is huge. Acute hypoxic wounds, we've talked about some chronic wounds. We've talked about radiation issues. We've talked about diabetics. Those are your chronic wounds. But now let's talk about some acute wounds. We've talked a little bit about compartment syndromes. But what about flaps and grafts? Acute arterial insufficiencies such as central retinal artery occlusion. These are issues where we have sudden loss of perfusion to tissues due to a clot. Now the body will recanalize. The body breaks down clots. How many of you have seen CTs or CT angiograms of patients who had strokes years before? They still have blood flow in those areas. The stroke, that blockage doesn't last forever. But unfortunately, the blockage lasts long enough that the tissue dies off. So now our goal is if through hyperbaric oxygen, we can keep those tissues having enough oxygen so that when the body recanalizes, when the body breaks down that clot, we keep the tissue alive. And that's the exciting part, and that's our goal. I want to talk about strokes because strokes are something that we don't have good evidence for with hyperbarics at this time. We're actually doing a lot of studies in mild traumatic brain injury. There's a hobbit trial going on in multi-centers throughout this country, including the military, to look more into details. Most likely, we just haven't found the right patient population because stroke is such a big phenomenon. But for now, there is no indication for stroke. However, if it's sudden, like a stroke of the eye, it is okay to turn a blind eye to the chamber. We do have very good evidence, and we'll talk about this. This is a case I saw a couple years ago, 54-year-old female journalist, very active journalist at a big paper in the city I was working in. She had a history, a prior history of loss of vision in the right eye secondary to optic neuritis, so she only had one eye, one good eye. She was sitting at breakfast, and all of the sudden, boom, almost complete loss of vision in her only good eye. A journalist, needed to be out there, needs to see, hear, listen, type, do what's going on. Luckily, she went to the ED right away and was transferred to our facility emergently and was diagnosed with central retinal artery occlusion. All she could see is fingers in the periphery, nothing in her central vision. We got her into hyperbaric therapy quick, within just a few hours of treatment. On her first treatment, taking her down to a depth equivalent of 60 feet of salt water giving her 100% oxygen, she could see. She could see with that eye. She was amazed. A little bit blurry, but she could see. Then we had to finish the treatment. Slowly the vision went back to where she was when she came back in. That's all right. A few hours, eight hours later, we gave her a second treatment, again, repeating that nice deep treatment. She had a partial loss of vision, but it came full return of vision during treatment and then partial loss over the next 12 hours, but only a partial loss, already better. We did a total of five days of repeated treatments, two to three times a day, and stabilized her. When she was discharged, she only had about a 10% loss of vision on her inferior temporal field. Her career was protected, all because of hyperbaric therapy. Well, Dr. Sanders, you just told me one case. You had one great case. Show me the evidence. Oh, sorry. I've got a few more slides before I show you the evidence. Why did this work? Why did this work? Under that increased hyperbaric pressure, not only do we get more oxygen in the blood cells, but when you get that, or sorry, not in the blood cells, in the blood volume, in the plasma, but not only do you get that in the plasma, but with that increased oxygen pressure, you're going to diffuse further away from those capillaries. That oxygen can penetrate further because it's higher pressure, that steep gradient that we talked about earlier. Under normal pressures like now, a capillary can only deliver oxygen about 64 microns from it. Now, I have no idea what 64 microns is, but if I tell you under hyperbaric conditions, 100% FiO2 at 2.4 ATA, that 45 feet that Dr. Alleman mentioned, now that diffusion distance is 247 microns. I can do the math from 64 to 247. Four times further from the cell, we can oxygenate properly, or four times further from the capillary, we can oxygenate properly than we used to be able to do. And that is really why this is such a definitive treatment for failing flaps and grafts and central retinal artery or other acute arterial insufficiencies, because now those patent blood vessels can deliver oxygen to an area that otherwise has lost blood flow. And then this is also one of the reasons why it's so effective in our diabetic foot wounds and osteoradionecrosis, soft tissue radionecrosis. What is unique about the eye? Well, the eye and the retina is one of the most metabolically active tissues we have in the body, so much so that it actually, like your computer, has to have a heat sink. So even though the retina has one blood vessel that gives all of its blood, the central retinal artery, and you block that off, your eye is going to go blind. One blood vessel in for the entire retina. Not necessarily the best design, but it is what we've got. And then you have this heat sink behind it, because it creates so much heat, we would kill the cells off if we didn't have that heat sink, and that's called the choroid plexus. That choroid has three posterior ciliary arteries. So three vessels that feed the choroid, one vessel feeds the retina. If we lose the retinal vessel and we put you under hyperbaric oxygen, that choroid can deliver enough oxygen to penetrate through the retina with that increased diffusion distance to really keep that ischemic penumbra, if we will, alive. So you have one blood vessel blocked off, but these blood vessels behind it now can give the oxygen needed to keep those tissues alive. Now I've said a lot. Show you the evidence. I will show you the evidence. Compromised flaps and grafts. In the study by Perins and others, we've seen complete survival of grafts, 64% versus 17%. Where do I see this most commonly? I see this most commonly in patients who have survived breast cancer and are undergoing reconstruction. And now with everything they've been through, the flaps and grafts for their reconstruction are failing. And these are just, this is tragic. My wife's a breast cancer survivor. This is something that's near and dear to my heart. So being able to help these patients through what is one of the most incredible times of their lives is really rewarding. If we can normalize this, if we can heal them quicker, if we can get them back to normal quicker, we can get them back to work and normalize their lives. And isn't that what most of our patients want? Is more of a normal life to feel like they're back, feel like they're contributing, feel like they're a part of society. When we talk about central retinal artery occlusion especially, Perins and others did a study where with all of the things that every optometrist and every, sorry, ophthalmologist can do, all of their skills, at best they see 29% significant improvement in central retinal artery. It's that serious of a problem. With hyperbarics, we can get that up to 82% if we can treat these patients within hours, six to 12 hours. So in conclusion, when looking at that, we know that as occupational physicians, we frequently become in a sense our primary care physician. I'm just as guilty. I have a primary care physician. He knows who I am. I know who he is. But I see my occupational physician at NASA every single year. She knows everything that's going on with me. She's the one that I rely on. She's the one who's telling me you have hypertension, you don't, you're treated properly, you're not, your cholesterol is high, your cholesterol is low. Not my primary care physician. I do the same thing for those patients that I see in our clinics. We are in a sense their main physician contact. Whether or not we're their primary, we're their main physician contact. So we can advocate to help keep our workers working in spite of occupational injuries, certain chronic health issues that put them at risk in the workplace, diabetic feet, history of radiation, certain vascular and infectious issues. We can benefit. Now, if you want some more information on hyperbarics and on the indications, I highly recommend reaching out to the Undersea Hyperbaric Medicine Association, Hyperbaric Medical Society, uhms.org. Or, tomorrow at 945, Dr. Alleman and I will be back to talk to you about education in hyperbaric medicine and the different options from one day, four day, and longer programs to help you learn more. Some good references for your library and references that I use, this book here, Hyperbaric Oxygen Therapy Indications, is fantastic. 120 pages, easy read, gives you a lot of the evidence, a lot of understanding of what's going on, and then several gold standard textbooks. We wanted to make sure we had plenty of time for questions because for so many of us, this is something that we've heard about. We know about it in diving, but we don't realize the benefits to all of our practices. So please, at this point, we'd like to open it up for questions. Yes? Have there been any studies of this? We are recording this, so if you would like to, if you don't mind coming up to the microphone, we'd appreciate it. Have there been any studies of this in post on my patients, like in hibernating myocardium? I mean, there are, I think there, it would be unethical to withhold obviously thrombolytics or go into the lab for a direct thrombus extraction, but in that patient that has, is post MI and their EF is, say, less than 45, are there any studies in hyperbaric oxygen to increase the contractility of the hibernating myocardium? I'd like to turn that over to Dr. Alleman, if I could, but just to give a little bit of history, actually, and some of the issues. So back in the late 60s, hyperbarics was used in operating rooms, at hyperbaric operating rooms. And we found that patients did so much better, especially for heart surgery in those cases. But as time has gone on, we know that the things like ECMO and bypass, and then with cath labs, have become the heroics and the heroes. So that's one battle we have since we're adjunctive. The heroes say they can do it, and we don't need you to come in necrotizing fasciitis is another one. We will do the surgery. We don't need you to come in unless we start to fail. So we're not seeing the patients. We know that hyperbarics has good evidence for ischemia reperfusion injury, but I'm not sure of any evidence for actual MI. So Dr. Alleman? There are no studies right now that I know of, but I'll tell you what's on the horizon, and this is exciting. There's a doctor in New Orleans, Keith Van Meter, who's emergency room doctor, and over the hyperbaric center there. He is advocating for two things. One of them is hyperbaric conditions in ambulance services, so that maybe when they do have a myocardial infarction, they can maybe get oxygen on the way in. And then the other thing, which I think has been done before, is hyperbaric oxygen in the operating room. So those are two areas that may get expanded in the future, but I don't know of any studies right now. Sorry, I have actually three quick questions. I have some experience in this. I did wound care with hyperbaric about 20 years ago. So just, I guess, by way of update, at the time there had been some thought that we didn't want to use hyperbaric oxygen on people with active cancers because of the thought of increasing metabolic rate and increasing growth rate. Second thing is, is there been any update or any evidence to show the effectiveness in acute sickle cell crisis? And then my third question is... What was the second question? I'm sorry. Acute sickle cell crisis. And then I guess my third one is, you often see athletes these days who are using hyperbarics to recover faster. Is there any evidence that that actually works? Okay, so first question. Sorry about all of them. Cancer. Cancer, yes. So that was a concern at one time. Are you going to cause new blood vessels or new cancers to grow? And that's been disproven. It works, the way hyperbaric oxygen works is it grows blood vessels into hypoxic areas and it doesn't affect cancers. At one time we didn't want to treat people who had active cancer. Now we do. So that's been disproven. Second question was? I'm sorry. Sickle cell. Acute sickle cell crisis. I don't know of any studies, but if you're increasing the oxygen tension, obviously those areas of the body that are deficient of oxygen, it would make sense that you can improve their oxygenation. However, we don't have an application for that. And then the third one again? The use of hyperbarics to recover musculoskeletal injuries. That's a very good question. And I think some of our brain injury research is going to maybe cause more of this to happen. I do know of several stadiums in the country that have hyperbaric oxygen facilities. And I'm not sure what all they're using them for. Whether it's acute injury to let's say a musculoskeletal injury or if it's just the concussions and brain injuries. We're still researching that question. Thank you very much. I do think there is some good science behind it in the sense that when we have lactic acid buildup and we've switched over from an aerobic to an anaerobic metabolism, we do improve recovery. And I think the evidence is there to show we improve recovery. But what does that mean? So let's talk about that. We won't ever, our medical society won't accept an indication that doesn't really change outcomes. So just because we can get that athlete back into the game a day earlier or two days earlier doesn't make a real difference in society. Getting your worker who might just be a little bit sore, okay, they won't be as sore the next day, well, ibuprofen does that pretty well too. Whereas in athletes where if I can get you back in the game today or get you playing tomorrow it's worth the hundreds of thousands of dollars of outlay for the hyperbaric. So it's something that is, would be statistically significant but not clinically relevant or clinically significant in society. So I think that's one of the issues where for the athletes indeed it does make a difference and there is good evidence where the oxygen will help to speed up the process but it doesn't really make a change, make a difference. Last question since we're running short. Are we? I'll be quick, I promise. You have time. Question about the plateau that you receive when you perform hyperbaric oxygen therapy on wounds. If you have a diabetic wound that doesn't completely heal and it continues, is there any indication of continued treatment afterwards, is there a time frame? And also do you have trouble getting paid because you've failed to fully treat it? Yeah, so yes, if we give extra oxygen, let's say a lot of times we're going to ask for maybe 30 treatments and we'll get to 30. Sometimes they're healed, sometimes they're not. 30 treatments is going to take us about 6 weeks. Will it, the studies say it takes generally 12 weeks but you've started that process of growing those blood vessels, the angiogenesis. If you give more oxygen, yes, you're more likely to heal that wound. Second thing on reimbursement, well, insurance companies run our world, as they do a lot of worlds, so if they say they're not going to pay, then the employee or the patient will unlikely be able to continue their treatment. My apologies. We are on a break, so we'll stick around throughout the break to continue answering questions. I'm so not used to being on a 1245 to 145 schedule, so my mindset was we were going until the hour, so I apologize, but we're happy to take questions during the break and now we have a break until 2. Thank you. Or no, I'm sorry. We don't have a break. I'm off here. No, that's us.

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