Case Study: Frostbite on Denali
With incoming winter temps and atmospheric rivers heading back to California I thought it was a good time to review a case study on prevention and treatment of cold injuries. If you are looking to learn more about hypothermia you can view last year’s January treatment of hypothermia article.
This case study is based on an incident on Mt Denali- but keep in mind frostbite is a risk factor even in California.
Incident Scene (taken from Accidents in North American Climbing 2022):[i]
In May 2022 on the west buttress of Denali at 14,200ft winds were gusting up to 40mph. Two men in their 50’s ignored warnings from park rangers that winds will be even higher further up and attempted to gain high camp at 17,200ft. Park service rangers observed the men taking roughly 7 hours to gain the fixed lines and being forced to make camp on the exposed ridge.
During the night their tent was destroyed by the wind and the team was forced to abandon camp and retreat back to the 14,200ft camp the following day.
If you were the rescuer what are your concerns?
Cold based problems
Hypothermia
Frostbite
Altitude problems
High Altitude Pulmonary Edema (HAPE)
High Altitude Cerebral Edema (HACE)
Based on the scene alone, any of the above are possibilities. HACE is actually the least likely, due to the descent back to 14K. HAPE is also less likely, but not to be ruled out as its often-slower onset and more insidious. A cold stress is GUARANTEED. Meaning that the cold will have been a physiologic challenge no matter what. It’s just a question of whether it led to anything worse.
After assessment:
One male sustained frostbite to his entire right hand. Frostbite extended to all digits except the thumb. No other medical problems were listed in this incident.
Notes:
It is very likely that this team would have been on the edge of hypothermia once they were trapped on the exposed ridge without shelter. I can think of a few reasons that they may have managed to stave off hypothermia but not frostbite:
- Food/Calories -if they had enough provisions to eat throughout their incident then they would have enough energy to shiver and produce some heat.
- Forced Exertion- The effort to dig out camp and even abandon camp would have forced these two to exercise, keeping core temperature up.
- Our hands and feet are cooled faster than our core. This is due to our body prioritizing blood to the core and away from the surface of our skin where heat is being lost.
Incident Outcome:
Rewarming of all the injuries was done while still on the mountain. No more details were provided on the severity of the injuries.
Notes:
Extent of damage from frostbite can be hard to know. Initially the rewarming will be very painful. Blisters may appear within in 24 hours. The full extent of damage won’t be revealed until 3-6 weeks! In essence- rewarming is a serious endeavor. Below are things to keep in mind when rewarming frostbite.
Steps to rewarm[ii]
- Remove from cold environment.
- Moist rewarming (hot soaking)
- Do NOT rub injured area
- Ideally 37c Degree water (over 15-60min)
- Pain management
Do they get to continue?!?
No, these climbers were evacuated due to lack of equipment. Tents and bags were blown off the mountain. As well as an inability to self-arrest due to injuries.
Where I take issue with this article:
Re-warming of frostbite isn’t always recommended. Decision making around this should be addressed so that people can make effective medical and evacuation-based decisions about freezing injuries. Specifically, if it is superficial frostbite (sometimes called frostnip) it should be immediately rewarmed in the field. Whereas deep frostbite is best rewarmed in a hospital setting. Ideally this can happen within 2 hours[iii] as frozen parts will often spontaneously rewarm once removed from the cold environment. Wilderness Medical Associates gives a more generous field rewarming timeframe of delaying rewarming up to 24 hours- provided the limb wont spontaneous rewarm. There are times where leaving an appendage frozen to keep self-evacuation viable could be considered (re: keeping foot in ski boot).
Secondly, they make no mention of how important it is for this injury to not re-freeze. This should always be considered when deciding if someone can stay in the field. Injuries that re-freeze have considerably more damage.
Lastly the prevention recommendations by the NPS lacks specificity that matters with these injuries. The National Park Service stated that ‘frostbite injuries account for over 25% of patients treated’ at Denali. They also go on to say ‘climbers must take active steps to warm any cold body parts prior to continuing an ascent’. Anyone in the mountains should learn how to identify signs of being cold vs superficial & deep frostbite. First off there’s a difference between feeling cold and freezing skin.
- It must be below -4c or 25F for frostbite to occur.
- Frozen skin will look different then the skin around it. How it looks depends on skin color- with darker pigmented skin reported as looking more blue and purple vs pale skin being white and wooden. It’s best to look for skin changes with clean demarcations (distinct edges) without getting hung up on specific colors.
- Superficial: Skin rebounds when pressed surface skin may still move freely over underlying tissue
- Deep: Skin may dimple, feels hard or wooden
So I would adjust the final recommendations to ‘Climbers should stop to address cold body parts as SOON as they feel cold BEFORE it becomes frostbite and involves serious injuries and complications.’
[i] Accidents in North American Climbing 2022
[ii] Alaska Acute Frostbite Management Guidelines
[iii] Dr Brownson Frost Bite and Burns guest lecture Wilderness Medical Associates
