gms | German Medical Science

Objective: Acute mountain sickness (AMS) is characterized by nonspecific symptoms like headache, loss of appetite or nausea, dizziness, fatigue, insomnia, and peripheral edema that usually occur within 4–8 h after rapid exposure of non-acclimatized individuals to altitudes above 2000–2500 m [1]. There is no gold standard to predict AMS to date. However, there are studies reported the correlation between SpO2 at low altitude and AMS at higher altitudes [2], [3], [4]. Therefore, the purpose of this study was to investigate the relationship between SpO2 and AMS in female Iranian climbers during ascent from Lukla (2800 m) to the Mera Peak (6654 m).

Material/Methods: Eight female climbers (age: 34.4±8.7 years) who were selected from 35 climbers and dispatched to Himalaya by mountaineering federation (Kermanshah province) participated as subjects, voluntarily. Climbing rout was from Lukla to Mera peak summit with overnights at 3310 m, 4150 m, 3525m, 4210 m, 5100 m, and 5800 m altitudes. After arriving in all camps, SpO2 were measured using pulse-oximeter (Nonin Onyx II 9550). AMS symptoms were assessed using Lake Louise scoring system.

Results: Means ± SD for SpO2 at 2800 m, 3310 m, 4150 m, 3525m, 4210 m, 5100 m (day 1), 5100 m (day 2), and 5800 m were 93.0±1.2, 92.4±1.4, 86.3±2.6, 92.0±1.3, 87.6±2.4, 82.0±2.2, 84.3±0.9, and 72.0±4.9, respectively. There was no significant correlation between AMS symptoms and SpO2 values. However, there was a significant increase in SpO2 from day 1 to day 2 in the base camp (5100 m) (t7= –3.63; p=0.008).

Conclusion: In conclusion, there is no relationship between SpO2 at low altitude and incidence of AMS at higher altitudes during a Himalayan expedition to a 6654 m summit. However, for this conclusion, the small sample size should be considered as a limitation. Another finding was that with staying at altitude for more than one night, acclimatization would occur and this acclimatization is confirmed by the increase in SpO2 at 5100 m.