Question

1. When climbing Everest, climbers generally take 12 days hiking from Lukla, Nepal (altitude 4,593 ft) to Basecamp. What is the change in the SaO2?
   1. Climbers generally spend 4-8 weeks at Basecamp getting acclimated. What is the SaO2 at this altitude? Is it within safe limits to be exerting oneself?
   2. Once climbers arrive at Camp IV they have very limited time, even with supplemental O2, to remain at this altitude and attempt to summit. What is the SaO2 at this altitude without supplemental O2?
   3. What is the PO2 and SaO2 at the Summit?

Extra info:

Place/Peak Altitude Air Pressure (mmHg) PO2 (mmHg) SaO2

Sea level 0 ft 760 mmHg 159 mmHg 100%

Denver 5280 ft 620 mmHg

Mauna Kea (HI) 13,803 ft

Long’s Peak 14, 259 ft

Mt. Fairweather (AK) 15,325 ft

Mt. Bona (AK) 16,500 ft

Denali (AK) 20,310 ft

EVEREST

Basecamp 17,600 ft

Camp I 19,900 ft

Camp II 21,300 ft

Camp III 23,622 ft

Camp IV 26,000 ft

Summit 29,028 ft

Answer 1

Everest base camp (altitude 5,300m; 17,388ft)

Oxygen saturation = 87% it is safe to exert oneself

Camp 2 (altitude 6,400m; 20,997ft)

Oxygen saturation = 78%

Camp 3 (altitude 7,100m; 23,294ft)

Oxygen saturation = 69%

‘Balcony’ (altitude 8,400m; 27,559ft)

Oxygen saturation = 54%

At Summit of Everest :

The mean PaO2 and PaCO2 values were 24.6 mm Hg (3.28 kPa) and 13.3 mm Hg (1.77 kPa).

The mean PIO2 value at 8400 m was calculated to be 47.0 mm Hg (6.27 kPa).

The mean PaO2 and the mean alveolar–arterial oxygen difference were 30.0 mm Hg (4.00 kPa) and 5.4 mm Hg (0.72 kPa).

answered by: anonymous