Fast Push #2: Safeback SBX for Avalanche Asphyxia Prevention

In this episode of Wilderness Medicine Updates, host Patrick Fink delves into groundbreaking technology designed to improve safety during avalanche events. The focus is on SafeBack SBX, a Norwegian-developed device that supplies air to users buried in avalanches, potentially extending survival time. Patrick reviews new research published in the Journal of the American Medical Association, which demonstrates significant efficacy in delaying hypoxia during simulated avalanche burials. The episode provides an in-depth analysis of SafeBack SBX, its mechanisms, study results, and its comparative and complementary role alongside existing safety technologies like airbags. Concluding with potential applications and limitations, Patrick aids listeners in deciding whether SafeBack SBX is a worthy addition to their avalanche safety gear.

Links

Eisendle F, Roveri G, Rauch S, et al. Respiratory Gas Shifts to Delay Asphyxiation in Critical Avalanche Burial: A Randomized Clinical Trial. JAMA. Published online October 08, 2025. doi:10.1001/jama.2025.16837

Articles I've written about Safeback:

Suffocation or Survival: A Crucial Factor in Avalanche Burials

Avalanche Safety: Assessing the Safeback SBX System

First Look: Safeback SBX Avalanche Safety System

Chapters
00:31 Overview of SafeBack SBX Technology
02:55 Importance of SafeBack in Avalanche Safety
05:40 Details of the SafeBack Study
07:53 Study Results and Analysis
11:07 Implications and Future Directions
15:50 Conclusion and Final Thoughts

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Transcript

0:15

Hello and welcome back to Wilderness Medicine Updates the show for providers at the Edges. I'm your host, Patrick Fink. Today I'm doing a fast push. This format is my opportunity to get some fresh research out to you guys that I think is interesting. I'm gonna go a little bit deeper today. We're gonna dive into a new technology to mitigate risk when traveling an avalanche reducing the risk of avalanche burial. It's called the safe back SBX, and there's new research out October 8th, the day before I record this in the journal of. The American Medical Association, also known as jama, one of the top journals in medicine. And so I think this is really worthy of note, and I think it's potentially game changing in terms of technologies that can reduce risk in avalanche terrain. So we're gonna dive in first talk about what is the safe back SBX system, and then review this new independent research from the URAC group that was published in JAMA. Cover, how it works, the science behind it, what the research found. And where it fits into our avalanche safety gear. So to start with, what is safe back? SBX Safe Back is a technology that was developed by an independent Norwegian company. If you're familiar with the Avalon device, the Black Diamond Avalon, it is analogous to an Avalon. It's a fan-based system that goes into a backpack or vest and draws air from within the backpack around the sides of the backpack from the snow pack. And uses a fan to drive it out through the shoulder straps of the backpack and deliver up to 150 liters per minute of flow of air to the user's face. So if this user is buried in an avalanche, they get a supply of air delivered to buy their face. Unlike the. Black Diamond Avalon. There is no need to stick something in your mouth. Use a mouthpiece. There's lower potential for hazard, and it's triggered by pulling a handle on the shoulder strap, much like an avalanche airbag pack. So that can either be deployed before entering into avalanche drain, or at the time that an avalanche, occurs. The device has a stated runtime of about 90 minutes. It runs on disposable lithium AA batteries, and it weighs about 500 grams, which is lighter than most airbag systems, and comes in at a comparable price currently with a backpack cost in 752$900 in current form, available currently through RAID research in the United States. With more backpack companies to come Heli Hansen announcing that they're going to bring this to the US as well next year. Okay, so why does this technology matter? This matters because in avalanche accidents, asphyxia, or lack of oxygen is the cause of death in somewhere around 75% of avalanche deaths. And when a victim is buried in the snow by an avalanche. Their survival is very time dependent, so your survival at 10 minutes is pretty good. If you haven't died of trauma during the initial event, your survival at 10 minutes is about 90%, but at 35 minutes. It drops to 31%, it starts dropping pretty precipitously, beginning at around 10 minutes, and then really drops off after 35. We think that that's because people are asphyxiating. They do not have enough air to continue to survive. There are some prior studies that give some validity to the idea that giving airflow to someone who's buried would help them survive. A 2022 randomized controlled trial showed that supplemental air increased tolerance in simulated avalanche burial from 13 to 22 minutes, and an analysis by the same research group that performed the same study that we're gonna review today. I found that at least 41% of victims buried in an avalanche didn't have their airway packed with snow. This is an area where there's a lot of incomplete data, so that number could be much larger, but at least 40% of people could potentially benefit from this technology. And then Safe Back has done some internal testing. I've communicated with them about this, showing that in all different kinds of. Snow packs, they can still deliver adequate flow through the snow. And it's actually the snow you would not think that makes it difficult to deliver air. It's light powdery snow. Low density snow is actually harder to deliver air through because it has fewer air channels. It's the. Dense snow with large grains, which is typically what results after an avalanche because of all of the tumbling involved that can deliver even higher rates of airflow. So there's plausibility to this technology to determine whether this is actually effective. I have to applaud safe back because they backed some research that could have sunk them. The URAC Research Group is an independent research group in Europe that tackles big public health questions, and they've done some research in this space before, but Safe Back gave them a bunch of packs and said, Hey, study whether this is effective. And URAC came back and said, great. If it's not effective, we're still gonna publish the results. We good? Safe back. Said, yeah, we're good. we really actually wanna know whether this works. So let's talk about this study again. This was published October 8th in the Journal of the American Medical Association by I Sendal Etal. The title is Respiratory Gas Shifts to Delay Asphyxiation in Critical Avalanche Burial, A Randomized Clinical Trial. This was a pretty straightforward trial, but they have some study design that's pretty interesting that really improves the quality of their data. They screened a bunch of adults to participate in this study. 18 to 60 years old ended up getting a slightly narrower age range in the people who actually participated, but ultimately ended up doing 12 people in the intervention group and 12 people in the control group. And what they did in this study was they buried people face down. With at least 50 centimeters of snow over their head and torso, simulating a critical avalanche burial, and they were wearing equipment that allowed them to measure their respiratory parameters, their inspired oxygen, their expired CO2. They had probes in the snow measuring gas content around them. The intervention group had the safe back fan device present, and the control group had a device that was similar in all respects, including the noise that it made, except it didn't actually deliver error to buy the face. The participants didn't know which one they had, and indeed only the person responsible for activating the pac who was the lead investigator. Knew which device was which. So everyone else conducting the study was blinded to who actually had which pack. they buried people into the snow and they said, Hey, we're gonna let you go for at least 35 minutes unless your oxygen saturation dips below 80%. Or you ring this danger bell and say, I want to be done In the group that had the actual safe back device, if they reached 35 minutes, they then turned off the safe back. And simultaneously activated a sham device to make sure that if that group, did better, it wasn't just because of their burial conditions. they gave them the same conditions as the control group after 35 minutes. So what actually happened? In the device group who had the real safe back, 11 participants completed the entire 35 minutes. One of the participants requested early termination because they had tingling in an extremity. They didn't stop for any respiratory reasons of the people who had the sham device, the not real device. Seven were stopped early for an oxygen saturation, less than 80%, and four of them were stopped because of participant requests, three of which were for shortness of breath and one of which was for a panic attack. So that means that only one of the sham group managed to go to the full 35 minutes. so there was a really statistically significant difference in the time that could be tolerated under the snow while wearing the safe back device. In comparison to the sham. Also notable within the Sham group, the median time to reach an oxygen saturation of 80% was 6.4 minutes. And in the safe back group, everyone who completed the full length of the study, except for that one person who got the tingles, none of them experienced oxygen desaturation to 80%. Then when they flipped off their safe back. They started seeing the same kind of results in that group as they did in the Sham group. There was no difference between the two. So that difference that was observed between the sham and the safe back group was entirely due to the technology and not because of some other issue. So what do I take away from this study? I think this is a really great study. I think they did a really good job. It's an independent study. They have their own funding. They just got devices from safe back. I think there's a low risk of bias and I think that there was high quality blinding. It was a well controlled environment with uniform burials and they had an internal control that like turn off the safe back turn on a sham that ensured that the burial condition was uniform between the two groups. So the observed differences can be attributed to the technology. The results are impressive in that hypoxia was delayed for at least 35 minutes, and we really don't know the endpoint on that because they didn't try to go further. When I asked one of the study organizers why they did that, it was because they feel the best window where they've seen a lot of deterioration is up to that 35 minute mark. That's not to say that you couldn't stay under the snow longer with the safe back. The primary limitation of the study is the uniform burial condition, so we don't know if it would work as well if people were in different positions, different snow densities at different altitudes. In positions that resulted in what are called positional asphyxia, which is where. Snow packed around the torso prevents one from actually expanding the chest. A recent simulation study of tree well burials, which I think we've discussed on here before, showed that just putting people in a different position can lead to hypoxia a lot sooner. Still, the results are impressive and I think that it suggests a strong likelihood of benefit under real world conditions. Should we all just start using safe back all the time when we're in avalanche terrain? Should it replace airbags? I don't think that there's enough information to make that decision yet. It's important to recognize that this is a fundamentally different technology from airbags. Airbags reduce the likelihood of becoming buried by doing so. They prevent critical burial. They cut critical burial risk from 47% down to 20%. That reduces mortality from 22% down to 11%. So if you wanna make that sound really good, it cuts mortality in half. It's a 50% reduction. Beacons have an absolute mortality reduction of about 15%, surprisingly. The technology also has some of the same limitations as other technologies. Namely, the user has to trigger the device. You have to pull it. Airbags also don't work if you don't deploy them. Safe back has the potential to be deployed before entering into the avalanche zone. So you could start it before entering into a ski run. However, so far my personal experience using the device I have in my possession is that it's a little too hard to turn off. And so, because it's hard to turn off, you're not gonna turn it on before a run. And then at the end of the run, go digging around in your pack to turn it off. I've given the company feedback on that they're aware that there's room for improvement there. Also, this is only a useful technology if you're skiing or traveling with a partner, and that partner can in turn locate you and excavate you still reasonably quickly. It's not at all useful really to someone who is traveling solo that that person needs to focus on not getting buried in the first place. Otherwise, a device like this is only going to prolong the horrific time under the snow where they're not being rescued and there's no hope of rescue. And then finally, like all avalanche safety technology, it, you know, there's always the potential that using a new safety technology could influence our behavior. If you don't think that that's a real thing, and that's somewhat debated whether this effect called risk homeostasis is. Real or significant? Consider whether you change your backcountry behavior. If I took your beacon away, That's my mental argument. For the existence of risk homeostasis, I think you would behave differently. Skiing with no beacon. On the other hand, I think there's some interesting use cases, two use cases that safe back addresses, which are not addressed by other technologies currently. The first one is the potential for addressing snow immersion suffocation or tree well burial. This, as we've discussed on the show before, has a really high fatality rate. It's like 80 to 90% fatal and death is often within five minutes, and that's because of a combination of airway plugging, positional asphyxia. And, inability to gas exchange safe back could potentially help with this. If it was deployed prior to falling in a tree, well, maybe they develop a commercial product for use in a ski resort, a vest that can be easily turned on and off. It would be really the only technology that would aim to address this problem. We don't really know if it would work it would require a completely different study design and those things that I talked about. Airway plugging, positional asphyxia. Would potentially reduce the effectiveness of safe back under those conditions. Still, for a space that has no technologies currently, there's a lot of room to grow there and Safe back looks like the most promising option so far. The other case where Safe Back could potentially be quite useful is for rescuers or ski patrollers who are. Working in the tail of an avalanche slope in the runout zone down at the bottom where there's still existing hang fire or approaching from below. In that setting, I would expect safe back to be more useful than an avalanche airbag. Why? How do airbags work? They work through reverse segregation. This is best described as the Brazil nut principle. If you have trail mix and you shake it, the big nuts come to the top. An airbag turns you from a peanut into a Brazil nut. It makes you a bigger particle that's more likely to end up on the top of the mixture. After all of the shaking, if you're at the bottom of the slope, there's no time to shake and tumble. You're just getting hit by snow from above. In that setting, safe back could reduce the risk of exposure and prolong time available for rescue to people who are working in those avalanche paths. So in conclusion. Safe Back is a new technology that shows real promise for extending survival time during avalanche burial. So far, it does not appear to be a replacement for airbags or other safety technologies, and it's certainly not a replacement for a well-trained partner, but it may be complimentary. Our real world data on this is still limited to none, so field validation really needs to happen. We need some field experience with this. And where I think the big future direction is here is if safe back is combined with an airbag. If you have a fan powered airbag that also powers a safe back fan, that is kind of a Goldilocks technology that will both reduce the risk of burial and mitigate the effects of burial. And that's the first good argument I've heard so far for using a fan-based airbag. But that combination technology is still a few years away at best. So that's it for this fast push. I hope that you enjoyed this discussion of this paper. I'm gonna put the citation down in the show notes. You can read the abstract on jama unfortunately. Unless you have institutional access or a subscription to jama, you won't be able to read the whole thing. It is stuck behind an expensive paywall. That said, I think you know what you need to know after listening to this quick podcast. And you can start making a decision about whether safe back is a technology that you want to carry. Protect you against the risk of tree well burial or out in the back country for recreation or for rescue. If you have questions, comments, send them to Wilderness Medicine updates@gmail.com. If you have ideas for other shows or just wanna send some feedback, reach out to me. Share this episode with your backcountry partners, your ski patrol fellows. Until next time, I'm your host, Patrick Fink. Stay fit, stay focused, and have fun.