Change in oxygen saturation does not predict acute mountain sickness on Jade Mountain

Area of Science:

• Altitude Medicine
• Physiology
• Clinical Research

Background:

• Acute mountain sickness (AMS) is a common condition affecting trekkers at high altitudes.
• Predicting AMS is crucial for preventing severe outcomes.
• Resting oxygen saturation (Spo2) is a potential, non-invasive marker for altitude-related physiological changes.

Purpose of the Study:

• To determine if changes in resting oxygen saturation (Spo2) during ascent of Jade Mountain can predict acute mountain sickness (AMS).
• To identify risk factors associated with AMS development at high altitude.

Main Methods:

• A prospective trial involving 787 subjects ascending Jade Mountain (up to 3952 m).
• Resting oxygen saturation (Spo2) and heart rate (HR) were measured at multiple altitudes.
• AMS was diagnosed using the Lake Louise criteria (score ≥4).

Main Results:

• Subjects who developed AMS had significantly lower Spo2 at all measurement points compared to those without AMS.
• Younger age and less prior high-altitude travel were associated with AMS.
• Despite statistical significance, the observed Spo2 differences between AMS and non-AMS groups were not clinically meaningful.

Conclusions:

• Lower resting Spo2 was observed in trekkers with AMS on Jade Mountain.
• The study does not support the use of pulse oximetry for predicting AMS in this setting.
• Clinical significance, not just statistical significance, is important when evaluating physiological markers.