A personal story of acute mountain sickness (AMS)
“Race ya down”, my friend Liz took off from the summit of Mt. Quandary. Ahead of us stood a 2 mile scrabble through a boulder field with a 1 mile decent down a winding trail through the forest where we would descend from 14,265’ to 10,850’. In my experience, a 6 mile hike with 3,400 vertical feet was no feat. However, something was different as we approached the cars at the end of the hike. I noticed the start of a headache and I held onto the car to keep myself from swaying while taking off my boots. Thinking this was merely dehydration I finished my 3 liters of water – but that did not help. Once in the car my head continued to throb as we drove over Hoosier pass. Incoherently I mentioned that we should stop for Gatorade but the 64 oz of Gatorade did not abate my symptoms. In fact they worsened, my symptoms included severe dizziness, nausea, and a pounding headache. While my memory was hazy I knew this was not dehydration, maybe this was acute mountain sickness? But how could it be? I was in shape, lived at 5,400’, and this was my 5th 14er that summer. Was it possible to have AMS on the same peak I had climbed just weeks prior?
My name is Chris Whitcomb and I am a 3rd year PA student at the University of Colorado. This story is all too familiar for anyone who spends time at elevation. Thankfully by the time we hit Idaho Springs, 7,526’, my symptoms dramatically improved. After reviewing my case and talking it over with my peers I believe that I developed AMS with some elements of HACE mixed in. A quick calculation of the Lake Louise Score came in at 6, which would classify this episode as “severe AMS”.
Who is most susceptible to AMS?
A prospective study analyzed a total of 11,182 workers on the Quighai-Tibet railroad in Tibet. This study identified 6 independent risk factors for AMS such as: rapid ascent to elevations above 3500 m (11482’), sea-level or lowland newcomers, young people of age, heavy physical exertion, obesity, or SaO2 below 801. Another study in 2013 looked into various other predictive indexes for AMS and found that the level of activity (higher activity) and sex (male>female) lead to increased odds of AMS 2. A quick review of the above criteria showed that I was the perfect demographic for AMS. I am a young male who was exerting myself physically at altitude.
Will this stop me from hiking at elevation?
Not one chance! Last summer alone my wife and I backpacked and hiked over 250 miles in Colorado. Since the incident I now make sure that I have the ability to seek lower elevation if needed during all our outdoor adventures. I also pay close attention to how I am feeling as we ascend.
Should I take acetazolamine/Diamox before backpacking trips because of my past AMS episode?
A meta-analysis in 2015 looked at 7021 individuals to see if a past episode of AMS warranted medication to prevent future AMS episodes. Interestingly enough they found that the literature did not support it. This was in part due to the sporadic nature of AMS 3. I personally do not take a prophylactic medication before hiking at elevation, but this would be a great conversation to have with your medical provider if you are at all concerned.
Chris Whitcomb, PA-S3
University of Colorado
Class of 2018
References
- Wu TY, Ding SQ, Liu JL, Jia JH, Chai ZC, Dai RC. Who are more at risk for acute mountain sickness: a prospective study in Qinghai-Tibet railroad construction workers on Mt. Tanggula. Chin Med J. 2012;125(8):1393-400.
- Beidleman BA, Tighiouart H, Schmid CH, Fulco CS, Muza SR. Predictive models of acute mountain sickness after rapid ascent to various altitudes. Med Sci Sports Exerc. 2013;45(4):792-800.
- Macinnis MJ, Lohse KR, Strong JK, Koehle MS. Is previous history a reliable predictor for acute mountain sickness susceptibility? A meta-analysis of diagnostic accuracy. Br J Sports Med. 2015;49(2):69-75.
