 Welcome. This is your host, Craig Thomas, on Much More on Medicine, part of Think Tech Hawaii's live stream series, assisted by our engineers Rich and Ray. And joining me today are my colleagues Diana Felton and Jeff Nance, who both are treating patients at the Hyperbaric Treatment Center. Welcome. Thank you. It's great to have you here. It's exciting times because the chamber's reopened. It's meeting people who have been dining and had an event. And I'm excited about it. So I'm glad you could share. I thought we'd start by setting sort of the framework and the sort of underlying theme of our talks over the spring have been what makes up the pieces of our health care system? What conditions need early treatment and early recognition and also how do all the pieces fit together? So since this is an important piece for scuba divers particularly, but also some other poisonings and things, Diana's a toxicologist, so she may talk a little bit about those items also. I thought it was important to share with the community that the University of Hawaii has sort of relaunched the center and it's great news for all of us because as we'll discuss, you need early recognition of symptoms and early consultation and if treatment's appropriate, early treatment. And you definitely don't want to be flying to San Diego, for example, to get that. So Jeff and Diana, let's talk a little bit about what are we treating? Why do, what's the history of gas bubble disease from compressed air? Because it isn't always just divers. It could be, for example, construction workers working underwater, things like that. So who wants to go first? I'll start. Perfect. The initial recognition of decompression type illnesses was originally noted when bridge workers were being submerged into deep, to deep underwater environments to build bridges. I believe the Brooklyn Bridge was when they first found the first cases and they found that these patients or people felt fine when they were working and then when they'd come up, they started developing some really unclear symptoms and some of it was pain related and they felt that they were bent over walking funny and so they gave it the name the bends. And that's how it started with the recognition of decompression illness. Exactly. And it turned out as time went on and actually the early, the experiments that elaborated this were many years ago. You may know the dates, Jeff, I don't, but it was, I think close to 100 years ago. It was, yeah, it was over 100 years ago, well over 100 years ago. And they established that what was happening was the compressed air, and you're absolutely right, it was working deep under the surface of the water, which required compressed air to keep the water out. It was the compressed air dissolving in the people's bloodstream that then made bubbles when they came back up. So, Jeff, maybe you could describe the basic event of how how they discovered this and started a plan for how to both prevent it and treat it and give us some history of the Hyperbaric Treatment Center in Hawaii. As far as the case on workers, you're referring to the case on workers, yeah, well, the symptoms were obvious, but it was very mysterious for a long time. And the first person to come up with really a treatment protocol would have been Haldane, who was commissioned by the Royal Navy, and he came up with the first tables for decompressing divers, essentially. And it's still, Haldane in theory is still used in, you know, in tables. It was impressive work because he figured it out and developed an effective strategy. So, you know, a long time ago. Yes, it was 1906, I believe. That is a long time ago. So, and the people at risk for this are people breathing compressed air and under pressure themselves. So, mostly that scuba divers, certainly in Hawaii, it's almost always scuba divers. So, it was recognized relatively early that we had the need. And so, why don't you tell us a little bit about the genesis of the Hyperbaric Treatment Center, where it started, and get us through the status. The Navy used to treat the civilians, but there was enough dive cases prior to, like, 1980 that at the late 70s, the Navy said, we can't keep treating civilians. They were having to interrupt their training, all of their training scheduled to treat civilian divers. So, at that point, Frank Farm, who's one of our founding entities and some other folks, created the first Hyperbaric Facility, which was at the Kakaaka Facility. And they were busy enough that they got the funding to create the facility where we are now. So, in that real nutshell, that's where it came from. So, this facility has been active since 1994. August of 1994, I believe, was the first, they treated the first dive case. And you're actually a tenant in the Kuwakini Medical Center. That is correct, yes. We're part of the School of Medicine. Right. And honestly, I've been there ever since. And there was a little reorganization last fall. And part of the objective of this show is to make sure everybody knows that the state and university have sort of joined forces to sort of reinvigorate the chamber. And it's, I think, treated a couple dive victims in the last week. So, it's an exciting time. And our chamber is pretty unique, Greg. It is available 24 hours a day, seven days a week, 365 days a year, which is not very common in this country. We also are what's called a multi-place chamber, which means that we're able to treat multiple patients at the same time. And we have actually two main chambers so we can run them both separately with different timings and patterns at the same time. So, it's a large facility. And there are, we are the only center in the state that has the capability to take a patient in with an attendant with them to be able to treat diving emergencies and also the only one that's available 24 hours a day. And in addition, this chamber has the capability of a physician, perhaps, or some other worker entering the chamber while it's pressurized. It's an airlock system. And doing some monitoring and medical intervention while in the chamber, which is sometimes essential. Yes. Maybe the two of us, two of you could talk us through what it's like. You want me to start? Sure, you can. Well, there's a lot of analogies people use, but it is fairly spacious, our chamber. So, it's nice people that come in concerned about going in a little tiny tube are usually pleasantly surprised. You can sit, lay down, we can put a gurney in if need be, if the patient's, you know, requires, we can put on a gurney. And we've actually had patients with as many as three staff attending to them in there. So, it is quite sizable. And during the treatment, the air within the pressure is similar to room air. It's compressed and pressurized to a chosen depth. And there's different depths that are chosen depending on the problem. And, but there are periods of when the treatment requires people to breathe 100 percent oxygen. Yes. So, at that time, they have a plastic hood placed over their head and they, and a hundred percent oxygen is piped into the hood alone. Yes. So, they breathe that oxygen usually in a period of 20 to 30 minutes and then a period of five to 10 minutes off the oxygen, then back on and it rotates back and forth to give them, you know, as much oxygen as we can safely provide them at the pressurized depth. Yeah. Which is a really interesting process because, and just for the purposes of discussion, I think that you generally go to an equivalent depth of on the order of 60 feet or thereabouts. 60 feet of seawater. Yeah. That's close to two additional atmospheres of pressure, which is definitely noticeable. And I'm going to ask either or both of you to describe kind of what it feels like going down and coming back up. But just to touch briefly on the oxygen thing, too little oxygen is obviously bad. And too much. And oxygen is a gas. So, how much you're getting is determined by the pressure as well as the percent in the, what you're breathing. Too much is also bad. And that's why the process you described Diana is employed. Hundred percent to try to keep the tissues perfused optimally, but a little time off to let it wash out. So let's, let's describe you go into the chamber, that flimsy little door about four inches thick. I think it's like 700 pound door. The 700 pound door shuts gently behind you and gets, and it does, it fits perfectly and gets dog shut. Well, we go through a checklist. Yep. Essentially make sure everybody's good to go to start. And then they begin, the operator on the outside begins compressing the chamber is pretty much as fast as the patient can equalize. So for equalize talk about that equalizing the ears and sinuses. Yes. So the divers would be familiar with this process, but the divers in the audience but yeah, exactly. So it's like, you know, as you're going up in a plane or coming down in a plane, your ears pop. If your sinus may get a little squeeze and it's this is the same thing. Yeah, just a little bit more abrupt. What does it feel like? Well, the temperature increases because we're pushing all those molecules together. And we have the capacity when they when Frank set up this chamber, he went all in and we do have the capacity to heat and cool the chamber. But you can't completely overcome the laws of physics. So it does get warm in there. But it cools off very rapidly. And it's quite comfortable for the divers. It's the biggest difference is there's no visual reference in your change of death. Right. So that's the hardest thing for them to get used to. You had to clear your ears, but you're still not underwater. Yeah, you're you. Yeah. What would you like to add, Diana? It's actually surprisingly comfortable in there, but it does feel a little awkward as you begin because nothing's changing around you, but you're you definitely feel the pressure changes. You do. And I was struck. So, you know, when you learn physics in high school, TV equals NRT, that's the formula. And you're like, Oh, ends the amount of gases there. R is a constant. So that means that the only variable on the right side of the equal sign is temperature. And I knew that. I had never experienced it. And it's striking. It gets warm, even though the cooling, I mean, not terribly warm, but noticeably warm for sure. I was also struck by some other things. You do have to clear your ears a bunch. But that's okay. I expected that. voices sound different. Sounds are transmitted differently. It's because the air is more dense. We have at a inflated glove, it's shrink, the balloon shrink, you know, it's, it's fascinating. And it's, it's sort of an experience of the physical world in an unusual way. I think it's really cool. Yeah. So, coming back up. And a lot of ways coming back up is going to be the reverse. It's going to cool down pretty abruptly as you come up from pressure. Do feel a similar popping in your ears. And that sort of the noises continue. It is quite noisy. It's a large piece of machinery doing a lot of dramatic things. So you have a lot of machinery type noise. And the sound is conducted more readily than normal. So we're gonna take a little break. And after the break, we're gonna talk about specifics of the various gas bubble treatments we do. So again, this is Greg Thomas much more on medicine with guests, Diana Felton and Jeff Nance from the Hyperbaric Treatment Center. And we'll be back in a minute. This is Think Tech Hawaii, raising public awareness. Freedom. Is it a feeling? Is it a place? Is it an idea? At DiveHeart, we believe freedom is all of these and more regardless of your ability. DiveHeart wants to help you escape the bonds of this world and defy gravity. Since 2001 DiveHeart has helped children, adults and veterans of all abilities, go where they have never gone before. DiveHeart has helped them transition to their new normal. Search DiveHeart dot org and share our mission with others. And in the process help people of all abilities, imagine the possibilities in their lives. I'm Ethan Allen, host of likeable science on Think Tech Hawaii. Every Friday afternoon at 2pm, I hope you'll join me for likeable science. We'll dig into science, dig into the meat of science, dig into the joy and delight of science. We'll discover why science is indeed fun, why science is interesting, why people should care about science and care about the research that's being done out there. It's all great. It's all entertaining. It's all educational. So I hope to join me for likeable science. Welcome back. This is Craig Thomas, your host on much more on medicine with guest Diana Felton and Jeff Nance from the Hyperbaric Treatment Center. Nice to see you again. Just before the break, we were talking about sort of the history and the general circumstances and what it's like to be in the dive chamber. Now we're going to talk about the physics, my favorite. Honestly, this is pretty straightforward. And Diana, maybe you could talk about the relationship of pressure and volume and why this all works. Or think the key thing for understanding the processes that happen when people get decompression sickness or the bends or other dive emergencies has a lot to do with what we call the bubble theory, which is bubbles of gas building up in the body. And the key to understanding that is that pressure and volume or size of the bubbles is directly inversely proportionate, meaning that when the pressure goes up, the size of the volume goes down, the size of the bubbles goes down. And vice versa, when the pressure goes down, the size of the bubbles goes up. So as you go underwater or down in the decompression chamber, the pressure is going up. And so that means the volume is going down and the bubbles are getting smaller. And the same thing happens on ascent. So when you come up from scuba diving or you come up in the decompression chamber, the pressure is decreasing back to the normal atmosphere. And the size of the bubbles is getting bigger. So if you're diving and you're down below the water, the bubbles are small, they have the opportunity to disseminate out of your bloodstream and into your body tissues because they are small, because the pressure is increased. And if enough builds up, and then as you when you come up and they get bigger, if they're stuck out in the tissues, that's when you start to run into problem. Got it. And the reason why the treatment works so well is that we go back down to the pressure and make those bubbles back down to small and help them come out of the tissue. Perfect. That's a nice explanation. And I was thinking about potential real world example, which I'm going to try next time I go on a plane. I would suggest we bring a little balloon, blow it up and see how big it is when we're cruising elevation. It should be, I would think about a quarter less size. I don't recommend the opposite, which is you could blow up the balloon up in the air. And then as you land it would pop. So let's not do that. But that's sort of the bubble thing. So, Jeff, anything you want to add to that? Or maybe we'll talk about a pretty good summary of that. Yeah, I thought she did well. Yeah. So thinking about this a little more though, it seems like you could have two different kinds of air problems. You could have bubbles in the bloodstream or joints or wherever they end up. But you could also have expanding air in other parts of the body. And I'm thinking of the inner or the middle ear, the sinuses, but probably more importantly for this discussion in the chest. After all, our lungs are full of air. And as it turns out, there are two different kinds of expanding air problems. So one is related to those. So let's start with that kind of air problem. So that we refer to as a gas embolism or sometimes called arterial gas embolism or AGE. And gas embolism is exactly that. It occurs when the air in the small parts of the lungs, the alveoli expands and ruptures. And that air is then released into the bloodstream. And air in the bloodstream is never good. Not good. And those bubbles can travel. And most concerningly, they can travel to the brain. And they can cause obstruction of the blood flow, gets lodged in the blood vessels of the brain, cause obstruction of the blood flow. And then basically the parts of the brain cannot continue to work. So you end up with problems that are very similar to strokes in some ways, paralysis, difficulty speaking, in severe cases unconsciousness. And this is a major cause of divers coming to the surface on a scent and be coming unconscious, right, upon arriving at the surface. Right. And to be clear, we're talking about scuba divers here. Correct. Yeah, so interestingly, a few weeks ago, Tom Forney hosted a discussion about the early recognition and treatment of strokes, which it causes all about finding the stroke and figuring out a way to minimize or remove the clot. Well, this is sort of the same thing, which is, ooh, it's not a clot, it's a bubble, but then that effect is the same. Whatever is downstream of it, didn't get in blood. So again, it's early recognition, early treatment to make the bubble small and let the blood get through. Exactly. One minor difference is that, you know, stroke with a blood clot, you usually have one blood clot in gas embolism from rapid ascent from diving. You can often have multiple bubbles in the brain. So the picture is not always as clear as it may be from a blood clot type stroke, but it is many of the similar type symptoms. Yes. And so what that means is, like everything in medicine, it seems, history is key. So if I'm hearing you correctly, these kinds of symptoms should be present almost immediately on surfacing. Yes. Maybe even before you surface. Exactly. And so if we get a history like that, then we kind of have a good idea of where we should be looking. And it does raise a problem as well in that many of these people also run into problems with drowning and near drowning as a complication, because if you're ascending to the surface and you become unconscious before you make it, you're going to aspirate some seawater. And if you're unconscious at the surface, you may run into trouble as well. So again, very complicated, can sometimes be a complicated picture. Nothing good happens if you become unconscious underwater. I think it's safe to say. So that was a nice description. So how do you minimize the chance of this happening to you if you're a scuba diver? The main number one thing is don't hold your breath, particularly on ascent. So continued regular breathing, slow ascent, is the number one way. Diving with a buddy is useful as well to have someone available if you were to become unconscious. But the number one thing is slow ascent with continued regular breathing. Yep. I think that's true of when I learned a scuba. There were a whole bunch of rules. I'm kind of a simple guy. So I came up with these ones. Breathe normally. Don't go too deep. We're going to talk about that in a minute. Don't come up fast and don't get lost. And honestly, I think that almost all scuba-related events fit in some of those parameters. So let's talk about the other kind, the bends, the one those bridge workers had. And I'm going to preface it by saying we learned a lot years ago about the how deep you can go and how you should treat them. But what we've also learned is that human physiology is variable. Things are unpredictable. And I'm going to have you, Jeff, tell me how they developed the dive tables in the first place, because I think it's a sobering experience. Well, yeah, it was the Navy used human subjects, but Haldane used goats. So yeah, the number of different animals, people and animals have given a lot for what we know now. And to be specific, what the Navy did was they bent people. Oh look, if you're down at 90 feet for more than, I don't remember what the number is, more than 30 minutes, and you come up, you're going to have the bends, or at least a 50-50 chance, I think it is that you'll have the bends. That's how the tables were developed. I think it's astonishing they did that. But it also, the 50-50 thing matters, because it means that you can, you may not get bent if you exceed the limits of your computer or the dive tables, but it also means that you may get bent with following the tables and or the computer. The advent of dive computers incidentally didn't change anything. Yes. Still people get bent, and about half of all people who get bent were within the parameters. So much more importantly is early recognition of symptoms and seek attention so it can be ascertained. Let's talk about the bends now, how you treat it. So generally symptoms of the bends are going to come on fairly quickly after a scent from a dive. Most people notice some symptoms within six hours and almost all within the first 24 hours. So what kinds of symptoms? So the main things people feel are joint pain is usually is the most common. Some people get itching and a rash. Which is of course an example of interrupted blood flow to the skin in the little tiny vessels. Peristegias meaning numbness and tingling to the fingers, the toes, and it can be more severe than that. People can have paralysis, they can have difficulty walking, and in very severe cases you can have effects on the respiratory, cardiorespiratory system. So difficulty with your heart and your lungs breathing chest pain. Those are pretty unusual symptoms but can occur in severe cases. So it sounds a little bit like in strokes that the they could present with a variety of symptoms and it's wise if you've been scuba diving to if you have something strange a little balance trouble or oh I don't know numbness or tingling or this weird itching or more serious symptoms. Seek help because the symptoms can progress and treatment works. No point seeking help if there's no treatment. There's a treatment. Let's talk about the treatment. So the treatment is going to be repressurizing what we call crushing the bubbles, meaning making those bubbles small again and helping encourage the bubbles to come out of the areas where they are causing the problems, the joints, the blood vessels, the tissues, and in addition adding 100% oxygen really helps perfuse the tissues that aren't getting adequate oxygen. So the combination really helps treat this and it's usually a treatment of about five hours in the chamber at a depth of about 60 feet with slowly coming up slowly so allowing the time for the bubbles to come out of the tissues into the bloodstream and be breathed the air to be breathed out and generally people do quite well with the first treatment but most people require a second treatment the next day possibly even a third or a fourth depending on their symptoms and how they feel. Perfect and as most divers know the initial treatment the first aid treatment in essence is 100% oxygen and the other thing is what the real issue here is the difference in the pressure where you are diving and in the air you're breathing so sea level it's all from the water depth but if you were to get in a plane or even drive over the saddle road that difference is much larger let alone if you were to scuba dive up on the Monacao which has happened and did result in the bends so that's an important concept to remember let's talk a little bit any other comments about treatment of the bends treatment or anything about the bends at all we we have the capacity to treat much deeper than 60 feet as well and so we do have some some very deep tables as deep as 280 feet which were rarely used but we do have that capacity. Well and in Hawaii there are people diving very deep I know and there's also some other other technologies out different gas mixtures or even rebreaters so that capability could be valuable so I guess before we leave the bends I would just like to say there may be some stigma attached by divers uh thinking oh I must have done something wrong that's why I've got this sore shoulder but I'm not going to go see anybody because you know I screwed up no uh first of all we in medicine we treat people regardless of how they came to need it but secondly don't forget about half the time you were within your tables or you were following the computer so if you have weird symptoms after scuba diving get on oxygen get a medical evaluation and if need be the hyperbaric chamber will treat you so Diana I'm going to switch gears here you're a toxicologist let's talk about uh some toxic toxicologic uh interventions the chamber can perform yeah so one of the other uses of the hyperbaric oxygen treatment is to treat carbon monoxide poisoning tell me about carbon monoxide poisoning well carbon monoxide poisoning is when you breathe too much carbon monoxide and it replaces oxygen on your hemoglobin and prevents you from getting adequate oxygen to your tissues so the most common ways people get poisoned from carbon monoxide are um using generators inside uh breathing car exhaust in an enclosed area those are the main ways we see it got it we see it yeah and carbon monoxide has a tremendous affinity for hemoglobin and the idea is if you can get lots of oxygen pressure is a way to do that uh you can minimize the effects and just like with diving the first treatment is 100% oxygen but then pressurized is better well listen i'd like to thank both of you today it's been fun and i hope that people are getting an awareness of this tremendous asset to the community and we can serve our local and tourist divers so i appreciate you having us yeah again this is craig thomas i'm much more on medicine and we had guests today from the hyperbaric treatment center thanks till next time