Effect of Continuous Monitoring of Oxygen Saturation to Counter Acute Mountain Sickness in Physician Climbers: A Pilot Study

Acute mountain sickness (AMS), the most common type of high-altitude illness, represents a spectrum of symptoms that develop in lowland individuals, when they ascend to a higher altitude (Jin, 2017; Tannheimer et al., 2017; Burtscher et al., 2019). Pulse oximetry has been widely used in clinical practice because of its noninvasive measurement of pulse and oxygen saturation (SpO₂) (Burtscher et al., 2019). The aim of our study was to evaluate the value of continuous monitoring of SpO₂ to guide climbing activities to counter AMS in physician climbers.

A total of six physician climbers residing in Shantou City (8 m above sea level) were enrolled in this study. To celebrate medical school graduation, they traveled to the Daocheng Aden scenic area. They were randomly assigned to either the SpO₂ monitoring group (experimental group) or the control group. They drove to the foothills in several days and then climbed to the highest scenic point (from 4180 to 4700 m). The experimental group used a pulse oximeter to continuously measure blood SpO₂. They were asked to stop climbing and have a short rest whenever their SpO₂ was <75% and to resume climbing when their SpO₂ recovered to 85%. No restrictions on climbing activities were placed on the control group. The Lake Louise Scoring system was used to score symptoms of AMS (Roach et al., 2018). Those with a score >3 were considered to have AMS.

At 4180 m, all participants had a lowered SpO₂ and rapid heart rate (Table 1). The climbing time of the experimental group tended to be slightly longer than that of the control group, but the difference was not significant (p > 0.05). According to the Lake Louise diagnostic criteria, all climbers suffered from AMS at the end of the climb. However, the Lake Louise score of the experimental group was significantly lower than that of the control group (4.00 vs. 7.33, p < 0.05), indicating that continuous monitoring of SpO₂ to guide climbing activities may significantly reduce symptoms of altitude sickness and decrease the severity of AMS. Because AMS is an important factor affecting a climber or trekker's experience (Jin, 2017; Tannheimer et al., 2017), continuous monitoring of SpO₂ might be able to reduce the severity of AMS in climbers and trekkers undertaking an ascent as we studied.

This study is subject to some limitations. First, a small number of participants were included in our study, which is a general problem of alpine field studies (Tannheimer et al., 2017). Second, since we only included physician climbers, this result may not be applicable to the general population as most physicians are proficient in using a pulse oximeter and have a clear understanding of the clinical significance of SpO₂. Thus, it will be necessary and important to evaluate continuous monitoring of SpO₂ beyond this special group of physician climbers and in a larger number of subjects.