Question

on top of a 25,000 foot mountain (MT Everest is 29,000 feet) the pressure is 282mmHg.

a) What is the PO2 at this level? Show calculations.

b) How will O2 arterial saturation be effected? Use numbers.

c) How must an individual accommodate for this altitude? Why?

d) Compare the effects to an individual at 15,000 feet without oxygen.

e) What is acute cerebral edema and what is the cause?

f) Commercial air flights are between 30,000-40,000 feet. How do you survive this altitude?

Answer 1

a.)

As, we move up the atmosphere the percentage of O2 in atmosphere reduces,

At, 25,000 feet height composition of O2 = 8%

So, partial pressure of O2 = 8% of 760 mm of Hg = 8/100 * 760 = 60.8 mm of Hg

b.)

Equations describing the SaO2 reduction with altitude are as follows:

1) for unacclimatized mountaineers, SaO2 = 98.8183 - 0.0001.h - 0.000001.h2,

2) for mountain dwellers, SaO2 = 98.2171 + 0.0012.h - 0.0000008.h2. (SaO2 in %; h: altitude in m. Lower limit of 95% confidence intervals given in the text). SaO2 of mountain dwellers is higher than that of unacclimatized mountaineers studied at the same altitude (p < 0.05 for any altitude over 1,692 m). SaO2 of mountaineers increased during early acclimatization (p < 0.05) to reach in few days the SaO2 of mountain dwellers.

Unacclimatized mountaineers who spent the previous night over 2,000 m had higher SaO2 in altitude than those who slept under 2,000 m (p < 0.05). Mountaineers who performed any high-mountain activity (i.e. over 2,500 m) in the previous 12 months had higher SaO2 on the summit of Aneto than those who have never been over 2,500 m before (p < 0.05)

c.) Going to a lower altitude is the best remedy. Acetaminophen, ibuprofen, or another over-the-counter pain reliever can be used to treat headaches, but it may not work in severe cases. Some ski resorts keep portable oxygen tanks available for rent, which can help until your body acclimates. Avoiding physical exertion can also help.

Yes, you can get a prescription for acetazolamide (Diamox), which causes your kidneys to excrete bicarbonate more quickly, helping you speed your breathing rate in a shorter period of time. It may cause dizziness or drowsiness and heightens your skin.