Category Archives: mountain

So maybe you can use that for a wilderness airway

We’re going to have to talk about the improvised wilderness airway. Caveat: this post is not exactly evidence based. It’s literally an anecdote. But an amazingly good and peer-reviewed anecdote at that. And there is a smattering of evidence thrown in at the end. Typical wilderness airway tool

The case report starts like this: Three firefighters were climbing as part of a team in California when they saw a man falling ~1500ft down a rocky slope. They descended to offer help, and when they got there they removed his helmet, checked ABCs, and maintained his C-spine. Neurologically he was unresponsive. Two emergency doctors with a separate climbing team arrived 15 minutes later. By this time his respirations were irregular and they noted significant facial trauma. Due to gurgling respirations, they decided to perform a cricothyrotomy.

All the physicians had for supplies were climbing equipment and a small first aid kid. They used a pocket knife to make the incision (vertical first, then horizontal), and tubing from a hydration pack as a makeshift ETT. Suture from the first aid kit was used to secure the tube. Since respirations were spontaneous, they did not perform positive pressure ventilations initually.

His pelvis was bound with a pair of pants, and extra clothes were used to prevent hypothermia. After 30 minutes though, his respirations became irregular again. Blood was noted in the tube, so the team decided to create a makeshift positive pressure bag using the rest of the hydration pack. One of the team would blow into hydration bladder to inflate it, and close it off using pliers as a valve of sorts. They would then deliver breaths by squeezing the bladder, similar to commercial products. They used this for another 30 minutes successfully.

Helicopter transport eventually was able to evacuate the man, and it turns out that a 6.5 ETT adapter fit into the makeshift tube easily. A bougie did confirm airway placement, and etCO2 readings were monitored. Unfortunately the patient went into V fib, got ROSC, then went into it again shortly after. The patient never regained pulses after that, and was pronounced dead prior to landing at the hospital.

The most important point of this case report isn’t the cool factor of Macgyvering other equipment into functional airway tools. It’s making the hard decision to perform the cric in the first place. Making that call, even in a low resource setting, is critical. Sadly this patient didn’t survive the injury, but it wasn’t due to lack of an airway. The fact that these physicians were able to also devise and then produce something that gives some form of PEEP is icing on the cake. However, it would be nice if someone took this device and measured what kind of pressures they could obtain with it.

And remember, if you’re going to perform a makeshift cricothyrotomy as your wilderness airway, make sure to use something of proper diameter. Ballpoint pens have too much resistance, but sports bottle and hydration bladder straws will work in a pinch.

Improvised Cricothyrotomy on a Mountain Using Hiking Gear
http://www.wemjournal.org/article/S1080-6032(16)30208-3/abstract

Maybe clothing technology really hasn’t gotten better

Early in the 20th century, explorers were busy trying to reach the poles and climbing mountains, simply because they were there. The casual observer from modern times must wonder how they were able to tolerate such cold temperatures without the high-tech fabrics available today. The mental images of Amundsen, Scott, Peary, and other cold weather explorers are often viewed as men laden with incredibly bulky furs and wool garments. How on earth could they achieve anything wearing that kind of clothing?

Credit: National Geographic/The Wildest DreamThat question has particular merit when considering the legacy of George Mallory and Andrew Irvine. They died in 1924 while attempting to summit Mt. Everest, almost 3 decades before Hillary and Norgay were able to do it successfully. Mallory’s remains were found in 1999 at 8157m, and his clothing was removed for testing before he was buried. After 3 years of intense study using multiple methods, they were finally able to definitively say what he was wearing.

But that only answers part of the question. Now that we know what he was wearing, was it enough to keep him warm but still allow freedom of movement needed to climb mountains? To test this, they simply replicated the fabrics, which were layers of silk, cotton, and wool. This was then covered with an outer layer of gabardine, faithful to the original made by Burberry.

(As an aside, many readers may not be aware of Burberry’s prowess in making clothing for polar expeditions. Like Abercrombie and Fitch, the clothing you can buy today is nothing in comparison to the rugged outdoor items one used to be able to purchase.)

So with that part answered, all that was left was for someone to climb Everest wearing the replica clothing. And Graham Hoyland did just that in 2006. He didn’t summit, but he did learn that the fabrics were light, comfortable, and more importantly, warm enough to use during the day. They were not, however, thick enough to survive a bivouac on the mountain in his opinion.

The part that made the outfit ingenious was the different fabrics of the alternating layers. This allowed decreased the friction between the layers, allowing movement with much less energy expenditure. This was demonstrated when tests comparing Scott’s to Amundsen’s layered garments showed a 20% decrease in said energy doing the same activity when more “slippery” fabrics were used (silk and furs versus wools). The same scientist also showed that Mallory’s fabrics would have been able to protect all the way down to -30C in calm weather.

Sadly, calm weather they did not have. A blizzard came upon them as they approached the summit, and they were last seen on one of the Three Steps. Whether this storm made them turn back or not, it certainly would have predisposed them to hypothermia. As to whether Mallory and Irvine actually summitted? We may never know, unless someone finds Howard Somervell’s camera with proof.

While these findings have done away with the myth that Mallory’s expedition was ill-prepared (based on photos from base camp), what they really show is that modern synthetic fabrics have only incrementally made gains in thermal protection, weight, and function. The argument can be made that tailoring them to fit properly is as important as the material itself.

I wouldn’t try to climb Everest in any modern garment made by Abercrombie or Burberry though.

Mountain Clothing and Thermoregulation: A Look Back
http://www.ncbi.nlm.nih.gov/pubmed/22441098

Additional Readings
http://www.alpinejournal.org.uk/Contents/Contents_2007_files/AJ%202007%20243-246%20Hoyland%20Clothing.pdf
http://www.independent.co.uk/news/world/asia/mystery-at-the-top-of-the-world-did-george-mallory-make-it-to-the-summit-of-everest-before-he-died-2063196.html
http://news.bbc.co.uk/2/hi/science/nature/5076634.stm
https://dspace.lboro.ac.uk/dspace-jspui/handle/2134/9716
http://thewildestdream.com/