Acute Mountain Sickness

There is a mention of high altitude illness in the Western States manual of possible medical emergencies during the race. I would like to take a moment to educate you on the PROBABLE occurrence of this event.

There are three terms common in describing high altitude illness. The first is Acute Mountain Sickness (AMS). A progression of this neurological event is High Altitude Cerebral Edema (HACE). The third term is High Altitude Pulmonary Edema (HAPE). This phenomenon is due to the rate of ascent to altitude and the absolute altitude reached. I will not discuss the pathophysiology of AMS, but give you some statistics to further your knowledge.

The highest point in the Western States Endurance Run is 8750 ft. The race starts in Squaw Valley at 6200 ft. During the first five miles of the run, a gain of 2500 ft takes place! Some entrants fly from sea level and drive up to the start immediately prior to the race.

• 20% of unacclimatized persons will develop AMS at 7000-9000 ft. (1850-2750m)
• Higher prevalence in persons under 50 years of age, children equal to adults.
• Physical fitness is not protective against high altitude illness.
• Persons with previous AMS have an increased risk of getting it again.
• Rate of ascent, altitude reached and individual physiology, predispose one to AMS.

Typically the symptoms develop within 6-10 hours, but sometimes as early as 1 hour. The hallmark is headache accompanied by any of the following; gastrointestinal symptoms (nausea and vomiting or loss of appetite), inability to sleep, dizziness, fatigue and sluggishness.

Given the number of race entrants from sea level, this is not a trivial problem. HAPE commonly occurs on the second night and for the time in the high country it is doubtful. HACE is a medical emergency and a progression of AMS, also doubtful due to the absolute altitude of the Western States trail, and the duration of time at this altitude.

Wilderness medicine reviews will advise a drug called acetazolmide (carbonic anhydrase inhibitor) for prevention of AMS. DON’T DO IT. It is a diuretic and can cause changes in the potassium sodium balance. It causes a bad taste in your mouth, tingling and numbness of hands, and dizziness. PREVENTION is the key to not developing this illness.

• Acclimate for three nights at Tahoe prior to the race.
• No sleeping medications or alcohol.
• Encourage good hydration and high complex carbohydrates.

Again, this is a brief summary of a complex and progressive illness. I hope it sparks questions and discussion.

Linda Lee

Burr, it was Darn COLD

Yesterday heralded the running of a very wet, cool and cloudy American River 50 Mile run. The weather channel predicted it. Prior to driving north to Auburn from Yosemite, I packed the car with my essentials for a day of Medical Aid at the finish line.

The problem for the day was HYPOTHERMIA. Hypothermia essentially means, “too cold to rock and roll”, or a core drop in temperature of 3.6o F. Accidental hypothermia occurs in healthy individuals with simple environmental exposure. Three degrees is not much of a drop, but it is enough to get you in trouble on the trail. And it just gets worse as your temperature falls farther and farther.

It was towards the end of the run when we started to get our REALLY cold runners. That is to be expected. These are the folks out there the longest, and are not in the elite physical condition as the top runners. One participant was from Texas where the weather is hot. She was not acclimatized to the sudden change in weather.

Humans have a basal heat production of 50m2 BSA/hour. It is increased with eating, fever, activity (running) and shivering. It is lowered when the runner is in a cool climate, fuel depleted, fatigued, and dehydrated. Cold and exhaustion is the common denominator for accidental hypothermia and it DOES NOT take an extremely cold temperature to produce hypothermia after energy depletion.

Aid station personal or other runners can recognize trouble on the trail. I worry about it during nightfall and the wee hours of the morning at Western States.
Besides being cold and shivering, the runner may exhibit amnesia, inability to find the right words, poor judgment, anxiety, or become apathetic to the circumstances.
As the pendulum swings farther towards lower body temperatures, the person becomes stuporous and body functions decline.

Accurate measurement of core temperature is impractical for field treatment of hypothermia. Correction is essential! A field impression can be made by the circumstances of the discovery, duration of the exposure, predisposing conditions, and don’t forget any associated injuries.

If the person cannot swallow, and their mental facilities are severely compromised, activate the emergency medical services. Otherwise, strip the individual of ALL wet clothing and shoes. Dry and insulate. Wool, synthetics, space blankets or plastic bags will keep the heat in. Layer. There is NO ROLE for cotton. Cover the head. Hot packs (chemical pads or hot water in Nalgene bottles) should be placed in the armpits, groin, and on the neck. Heat the Core. Feed the runner hot cocoa, tea, hot Jell-o, or hot Tang. If you can, turn on the heater in the car, and allow the ambient heat of the vehicle to assist. If sitting on the ground, provide a pad or some type of insulation.

Prepare for bad weather. Use drop bags. Have dry clothes placed accordingly. I just touched on the topic of hypothermia. Physiologically it gets very complicated, but recognized early on, and corrected appropriately will save the runner from spiraling downward.

Right, left, right, left. Linda Lee

All those L-O-N-G miles in the sun

We are all concerned with premature aging and skin cancer. The anti-aging industry is skyrocketing and the dermatologists have more work than they can keep up with. Every time I go to my dermatologist, I am told to stay out of the sun, especially between the hours of 10:00 and 3:00. Yah, right!

Ultraviolet (UV) radiation is invisible light waves that are shorter and more energetic than visible light. UV radiation is subdivided into categories based on wavelength. UV-B (320-290nm) and UV-A (400-320nm) are the two of greatest concern. UV-B causes sunburn, helps with Vitamin D synthesis, and is responsible for skin damage causing photoaging and cancer. UV-A is approximately 20 times more abundant, is not filtered by window glass. UV-A is unaffected by atmospheric conditions and is 100 times more likely to cause havoc to the skin. UV exposure is the primary cause for basal cell and squamous cell carcinoma! Sun exposure also increases the risk of developing melanoma. UV radiation directly damages cellular DNA and suppresses the skin’s immune system.

Besides wearing cover-up protection, sunscreens are needed for skin protection. Pick a chemical absorber or a physical blocker. Make sure that it is protective against the UV-B and the UV-A wavelengths. Apply generous amounts to all exposed skin and reapply every few hours.

I will be at the finish line of American River 50. I may see you there! Run safe, run wild, stay upright and mobile.

Linda Lee