All right, let's take the technology outside. So I hope to convince you by the end of my time here that taking technology outside of the hospital is possible, with a few caveats, and let's just dive right in and into a case. So this is a published case, it's a 32-year-old male with no past medical history that was part of a high-altitude medical research expedition team. They had a planned hike of 2,600 meters is where they started, up to 6,100 meters, and as part of the research group, they were doing nightly POCUS evaluation of the lungs, looking for B-lines and optic nerve sheath diameter. And everything was going great until day six, when our patient was at 3,840 meters, and as part of the nightly check-in, reported a minor headache. You can see, this is not the film from the case, the rest of them are. But normal lung scan, no B-lines. His optic nerve sheath diameter was 6 millimeters, 5 is sort of considered normal, 6 is, I don't know, and anything greater than 7 should make you concerned. There might be some increase in cranial pressure, notice all the caveats that I'm throwing out there. But that was consistent with his baseline at sea level. So day seven, felt better, resumed vigorous checking, got up to 4,300 meters by that evening. Vital signs were done, O2 stats were 89%, but at that altitude, 85 to 90% is within a normal range. His exam was normal, but now there were increased B-lines, and the optic nerve sheath diameter was the same. By day eight, now he had increased dyspnea and orthopnea, his O2 stats are 78%, and that is now decidedly not normal. His lung exam was normal, there's no cough or fever, but on neuro exam, he's now mildly ataxic. There were some problems with his tandem gait, but he still had normal mental status. So now their ultrasound showed an increase in B-lines in all fields, although no more than two. There was no pneumothorax, so going through that algorithm for why is patient hypoxic, and no pneumonia. Optic nerve sheath diameter is now 7, and so that's starting to get into that range where you might be concerned there's some increase in cranial pressure, and so what did the team do next? Well, they decided to still make sure that the pulmonary issue was not PE. So they did an echo. The only question they asked, this will be pertinent later, was is the right ventricle enlarged, yes or no? The right ventricle was slightly enlarged, but they did not feel enough so to account for a clinically significant pulmonary embolism. There was some mild pulmonary hypertension, but clinical deterioration plus the dynamic changes that they noted on POCUS were able to help them convince the patient to evacuate. Of note, the patient was an emergency medicine physician, and so they found it very helpful to sit there and show him his own films to convince him to leave. You would never have to convince me to leave that kind of environment, cold and very high elevation. They gave him some nifedipine. Interestingly, perhaps shockingly, they had no supplemental oxygen available. They decided as a team not to give steroids. He was evacuated by helicopter to Kathmandu, and by the time he got there, his chest x-ray and a TT were normal and his symptoms had resolved. So when we're talking about austere POCUS, the scenarios that we're thinking of are humanitarian missions, disaster scenarios, smaller expeditions like that one where there's medical support involved, and then certainly when we start to think where my expertise is, which is operational military medicine, we're talking both large-scale combat operations and prolonged field care. The common uses that most people think of when you talk about bringing POCUS in the austere area or the pre-hospital environment are diagnosis and triage, right? So e-fast, doing a lung ultrasound for pneumothorax, procedures in some cases. So at the ultrasound course over the past two days, the thing everybody was most familiar with was POCUS for procedures, so line placement. And then certainly to manage and monitor your interventions over time. The one case that does not get talked about often is whether you need to evacuate somebody, yes or no. And that is a really important yes or no question to answer because evacuation is resource-intense, and it's usually happening in a resource-limited environment. So this is published data out of CENTCOM, which is our area of operations in Iraq and Afghanistan. And to evacuate one injured casualty by helicopter, it requires four crew per airframe. No helicopter goes out by itself, so there's one or two or sometimes three airframe to accompany the evac helicopter. It's $10,000 just to start the rotor, but we're the American government, I'm not sure we care about $10,000. And if you're going to drive instead, it's nine crew for three vehicles to transport one person. So that's a lot of resources to move somebody from an austere area back through an evacuation chain to a higher level of care. There's an article published in Military Medicine by Sullivan that detailed a mission with the Brazilian Navy. Twice a year, they go down the Amazon River and provide medical support to tribes that are located in the Amazon jungle and don't have access to medical care. If they have to evacuate one of those people, it's $150 out of pocket if they can go by boat, if they can't get a ride from the Navy, and $3,000 by helicopter, and that doesn't include the cost of lodging for the patient and their family. So people don't have the resources for evacuation. So if you can answer some of these questions and avoid evacuation, you're saving a lot of time and resources. So here's an example from Adam Burkett. He's one of our Army internists. He was deployed with the Roll 1 in Poland, and they had a UK soldier present with lower extremity edema. They were able to do a very simple two-compression DVT scan and discover that it was actually superficial thrombus. They saved that person evacuation. Of note, it was teleguidance and telementoring that helped provide the diagnostic clarity. So they took the images, sent the images. Someone looked at them and said, yeah, you're good. That patient doesn't have to leave. This right here is a ruptured tendon. So somebody that presents with a musculoskeletal complaint and you don't know if they need surgical intervention or if they can stay and continue the mission or participation, a rupture in that tendon versus tendonitis is going to make you look at that differently. And then this is a little bit hard to see, but this is appendicitis. So you can, if you're lucky, you can find the appendix. And sometimes it looks inflamed. And so now you know that you've got appendicitis, and you can decide whether that's somebody that you're going to stay and keep and monitor and watch or if they need to leave wherever it is that you're active. So in osteoporosis, early on in the first 24 to 48 hours, those are the people that we're all thinking of. And when you arrive into a humanitarian scenario after an earthquake or hurricane, you're going to see patients that meet your standard triage categories. You're going to use POCUS for re-triage. That's where we bring in eFAST and lung ultrasound, where you're looking for pulmonary contusion and pneumothorax and those things. Later on, 48 hours now, the people that weren't immediately injured and evacuated are going to start coming into your area. What you start to see is a lot of musculoskeletal and obstetrics, which I know just made most of us really cringe internally at the thought of it, but a lot of first trimester obstetric ultrasound, so women presenting with pelvic pain or abdominal pain, and then abdominal pain in general, so the black box. If you don't have a CT scan, which is the answer to the black box, then ultrasound can really help you decide what's going on. Of course, in the military, we're always concerned about prolonged field care, which for our purposes means, I have a patient, I desperately need to get them to a higher level of care, but I don't own any of the space or means of transport to get them there, so they're mine until I can get somebody out to help me, and certainly POCUS is going to help you there with early and ongoing management and with procedures. Just a thought on equipment. There's a lot of questions that you need to answer before you grab an ultrasound system and head out into the wilderness, and we can go through these, but these are just some that you can think of, and you'll have access to look at these slides later. If for example, I was going to someplace where I knew that I was going to be in a fixed facility, I might have multiple probes that I want to bring with me instead of just a multi-probe, so I might want to bring a phased array and a curvilinear and a linear probe. I might need a pad or laptop, or I might even be able to bring a cart-based monitor versus something that fits in my pocket. My connection could be wired or wireless, and then as a battery source, if I know where I'm going, I'm going to have access to electricity to charge batteries, then I don't need to worry about infrastructure, I don't need to worry about generators or solar-powered battery recharging. A note on ultrasonic medium, just because I thought this was interesting, you know, in the Army, the Army medic's combat load, standard combat load is 75 to 90 pounds. So if you are going to add ultrasound and a viewing device and ask them to carry that plus some ultrasonic medium to use this at the point of injury, you better make sure every ounce counts. So this was a really nice study done by two of our Army PAs at Joint Base Lewis-McCorp in Washington, where they found a galactamannan powder substitute that's very light, it doesn't go bad, it can tolerate all of the heat and cold conditions you can put it through. You reconstitute it with a little bit of water, and you cannot tell the difference between that and the normal bottles of gel or tiny packets that you squeeze out, depending on what your hospital gives you. This is probably my favorite study that I have ever seen. Are there any Canadians in the audience? Yeah. So these were some Canadian emergency medicine, wilderness medicine guys and gals that decided they wanted to know what could possibly be in my backpack in the backcountry that would work like ultrasonic medium. And the great news is anything, including maple syrup, but not sunscreen. So sunscreen was the only thing that gave worse imaging than ultrasonic medium. So in summary, but my slide's not advancing, oh, there we go. Okay. In an emergency, any probe will do. Don't be picky. Where's my... Yeah, technologically challenged at the technology talk, that's awesome. Plug and play is ideal. Know your limitations. So we're not concerned about the Simpson's biplane method for ejection fraction. Is the heart beating, yes or no? Very important question in a scenario where you've limited resources, so keep it simple. Have one power source to fall back on. Lots of alternatives for acoustic media. You can always look at options for asynchronous consultation versus local consensus, which is everybody gather around the monitor and we all agree that this is what we think we're seeing. I'm not going to go through this because you had far, far better talks on this already here at our session and in other sessions. So in summary, I want to put in your mind that point of care ultrasound can be used for evacuation decision, which is a critical decision-making tool in an austere environment. And don't let perfect be the enemy of good if you're going to bring technology out into the wilderness.

point-of-care ultrasound

high-altitude expedition

austere environments

medical evacuation

ultrasonic media