The Basics of Altitude: A Primer on AMS, HACE, & HAPE, Part II
Last week, I wrote about the tragic death of Morgan Boisson, which in turn led me to a post about High Altitude Cerebral Edema, or HACE.
This morning there was yet another sad reminder of the dangers of altitude in my inbox. Today it was the story of John Campbell. Mr. Campbell was on a trek to the Basecamp of Kanchenjunga – the world's third highest peak – with Jamling Tenzing Norgay when he came down with what sounds like HACE. While valiant efforts were made by the Sherpa trek staff and by his daughter, Campbell sadly passed away on October 28, 2009.
While Mr. Campbell seems to have passed away from HACE, his death is still a reminder that we all should be prepared for high altitude ailments, and be ready to act on them, when we go into the mountains. Campbell was not a newcomer to altitude. According to web resources, he was an avid hiker, going on many trips into the High Sierra, and has already done treks to the Basecamps of Everest and K2.
So, last week we talked about HACE, and now it's time to discuss a bit about HAPE, or High Altitude Pulmonary Edema.
In my experience, HACE is a bit more common than HAPE, perhaps because studies point to it being a more intense form of Acute Mountain Sickness (AMS). I've personally run into cases of HACE on many expeditions. Last week, I mentioned the story of Miguel Tello, who had both HACE and HAPE on Nevado Huascaran in Peru.
On Everest in 2001, we had another, quite similar situation.
On May 7, 2001, Tap Richards, John Race, and I were ascending the East Rongbuk Glacier en route to Advanced Basecamp and the beginning of our summit bid. At about 20,000 feet, near the old pre-World War II Camp 2, we came upon 3 Tibetan yak herders carrying a sick Chinese glaciologist, Mr. Gao, down the mountain. Another Chinese scientist, Mr. Li, staggered behind; he was sick, too, but in much better shape.
We knew immediately that our summit bid was off; it was obvious to us that, if we did not act, Mr. Gao would most likely die before reaching Basecamp. He was barely breathing, unresponsive to pain, cold, and generally looking awful.
And so began a challenging rescue, carrying the 180 pound Mr. Gao on our backs, with amazing help from the yak herders and other Tibetans who came up, as well as additional members of our team. For hours, Mr. Gao slipped in and out of consciousness, at times choking on his swollen tongue and often looking like, despite our efforts, he was not going to make it.
But, finally, after about 10 hours of work, we got Mr. Gao into a jeep at the mouth of the Rongbuk Valley. Soon he was in our expedition Gamov Bag and being tended to by our expedition doctor, Lee Meyers. Early the next morning, in stable condition, Mr. Gao was loaded into a jeep and driven off to the hospital in Shigatse.
It was a close call, but Mr. Gao survived. (A week later, Mr. Li drove back into Basecamp with a box full of apples and pears, a nice thank you from he and Gao for helping save their lives.) Had Gao's teammates known the basics of high altitude medicine – and warning signs to look for – this all might have been avoided.
So, what do we look for as signs and symptoms of High Altitude Cerebral Edema? Here's some basics:
- Often one of the first telltale signs is a headache. Cerebral edema is fluid gathering inside the cranial cavity and putting pressure on the brain; thus, a persistent headache, which most often will not go away even with aspirin or ibuprofen, and coupled with ascent to a new altitude, is an early sign of HACE.
- Ataxia, or loss of balance resulting in unsteady walking, is another common sign of HACE. However, much depends on where the pooling fluid in the brain is putting pressure; various changes in mental and physical state can be evident:
- uneven pupil dilation
- slurred speech
- inability to remember basics like name, date, time of day, etc.
- loss of fine motor control
As with HAPE, these are the early warning signs, but things generally deteriorate rapidly afterward. In general, someone with early signs of HACE who is not treated will, within 24 hours, become unconscious, slip into a coma, and pass away. This is serious stuff!
But, again like HAPE, HACE does have some simple, effective treatments.
- DESCEND, DESCEND, DESCEND! Descent is the only surefire treatment for HACE, and again the rule of thumb is descent of 3,000 feet or more.
- If descent is not immediately possible, there are some options to "buy" some time:
- Put the patient in a Gamow bag, or Portable Altitude Chamber (PAC)
- Put the patient on high flow oxygen, 8 liters per minute or more
- If available, dexamethasone is a great medication for HACE. Dex is a powerful anti-inflammatory steroid which in this case helps reduce cerebral pressure from HACE. Whereas niphedipene works only sometimes in treating HAPE, I've found that dexamethasone is very effective in reducing the severity of HACE. Dex comes in tablet and injectable forms; I always carry both. As with any drug, know how to use dex before you go, and make sure your climbing companions do, too – it could save your life, or theirs!
Those are some of the basics of HACE. Again, these are the rules of thumb and actions I take whenever I'm climbing or guiding in the high mountains. I've seen HACE in climbers and others on Rainier, in Colorado, on Kilimanjaro, and of course in the Himalaya.
We all go into the mountains prepared physically, and prepared with our equipment. But, many people forget to be prepared medically as well. Know your body. Know the dangers. Know what to look for.
And, remember, the mountain will be there another day…the important thing is that you are around to climb it another day!
In the next – and final issue – of this primer, I'll talk a bit about the most important aspect of high altitude medicine: How to prevent these ailments from occurring in the first place! Rule #1: Choose your parents!