Evaluating Health Impact at High Altitude in Antarctica and Effectiveness of Monitoring Oxygen Saturation

Background The Japanese Antarctic Research Expedition (JARE) has been conducting research activities in inland Antarctica, which is extremely cold dryland covered with a thick ice sheet. This environment may cause a health disorder called acute mountain sickness (AMS). To improve the safety of expedition members, we evaluated the impact of extreme environmental conditions on human health and the effectiveness of monitoring of hypoxia for the early detection of AMS. Methods In total, 9 members from JARE 59 were studied. Dome Fuji Station (Dome F), located 3,810 m above sea level (ASL), was the destination of the research party. We analyzed daily AMS scores (higher values correspond to more severe AMS-related symptoms), physiological findings, and percutaneous arterial blood oxygen saturation (Sp02) during the inland activity. We also determined the factors related to AMS scores. Results The average AMS score on arrival at Dome F was significantly higher than that at the departure point (560 m ASL). The average Sp02 level was significantly lower than that at other points. The Sp02 level correlated negatively with the AMS score in Spearman's rank correlation. Generalized estimating equations analysis showed that the AMS score was negatively associated with Sp02 level and positively associated with age. Conclusion Hypoxia is a contributory factor to AMS which we can easily assess by measuring the Sp02 level with a pulse oximeter. Sp02 monitoring is a potentially useful health management tool for members in inland Antarctic expeditions. In addition, our results are helpful for understanding physiological responses and health issues in extreme environments.