在高海拔地区（3050-6354 米），登山者的血氧饱和度在夜间会升高。

Oxygen saturation increases over the course of the night in mountaineers at high altitude (3050-6354 m).

机构信息

Division of Sports and Rehabilitation Medicine, Universitat Ulm.

Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam.

出版信息

J Travel Med. 2017 Sep 1;24(5). doi: 10.1093/jtm/tax041.

DOI:10.1093/jtm/tax041

PMID:28931132

Abstract

BACKGROUND

Blood oxygen saturation (SpO 2 ) is frequently measured to determine acclimatization status in high-altitude travellers. However, little is known about nocturnal time course of SpO 2 (SpO 2N ), but alterations in SpO 2N might be practically relevant as well. To this end, we describe the time-course of SpO 2N in mountaineers at high altitude.

METHODS

SpO 2N was continuously measured in ten male mountaineers during a three-week expedition in Peru (3,050-6,354m). Average SpO 2N of the first (SpO 2N1 ) and second half (SpO 2N2 ) of an individual's sleep duration was calculated from 2h intervals of uninterrupted sleep. Heart rate oscillations and sleep dairies were used to exclude periods of wakefulness. SpO 2 was also measured at rest in the morning.

RESULTS

SpO 2N significantly increased from SpO 2N1 to SpO 2N2 . The magnitude of this increase (ΔSpO 2 ) was reduced with time spent at altitude. On night 1 (3,050m) SpO 2 increased from 83.4% (N1) to 86.3% (N2). At the same location on night 21, SpO 2 increased from 88.3% to 90.1%, which is a relative change of 4.7% and 2.0%, respectively. This pattern of increase in SpO 2N was perturbed when individual acclimatization was poor or altitude was extreme (5630m). SpO 2N was significantly lower than SpO 2 at rest in the morning.

CONCLUSIONS

This study is the first to demonstrate an increase of SpO 2 during the night in mountaineers at high altitude (3,050-6,354m) with high consistency between and within subjects. The magnitude of ΔSpO 2N decreased as acclimatization improved, suggesting that these changes in ΔSpO 2 between nights might be a valuable indicator of individual acclimatization. In addition, the failure of any increase in SpO 2N during the night might indicate insufficient acclimatization. Even though underlying mechanisms for the nocturnal increase remain unclear, the timing of SpO 2N measurement is obviously of utmost importance for its interpretation. Finally our study illustrates the detailed effects of ventilatory acclimatization over several weeks.

摘要

背景

在高海拔旅行者中，经常测量血氧饱和度（SpO 2 ）以确定适应状态。然而，对于夜间 SpO 2 （SpO 2N ）的时间过程知之甚少，但 SpO 2N 的改变在实践中可能也很重要。为此，我们描述了高海拔登山者夜间 SpO 2N 的时间过程。

方法

在秘鲁的一次为期三周的探险中，连续测量了 10 名男性登山者的夜间 SpO 2N 。从 2 小时不间断睡眠的间隔中计算个体睡眠持续时间的前半部分（SpO 2N1 ）和后半部分（SpO 2N2 ）的平均 SpO 2N 。使用心率振荡和睡眠日记排除清醒期。早晨还在休息时测量 SpO 2 。

结果

SpO 2N 从 SpO 2N1 显著增加到 SpO 2N2 。这种增加的幅度（ΔSpO 2 ）随着海拔高度的增加而减小。在第 1 晚（海拔 3050 米），SpO 2 从 83.4%（N1）增加到 86.3%（N2）。在第 21 晚同一地点，SpO 2 从 88.3%增加到 90.1%，分别为 4.7%和 2.0%的相对变化。当个体适应不良或海拔过高（5630 米）时，SpO 2N 的这种增加模式受到干扰。夜间 SpO 2N 明显低于早晨休息时的 SpO 2 。

结论

本研究首次证明在高海拔（3050-6354 米）的登山者中，夜间 SpO 2 会增加，并且个体之间和个体内部的一致性非常高。随着适应的改善，ΔSpO 2N 的幅度减小，这表明夜间 ΔSpO 2 之间的这些变化可能是个体适应的一个有价值的指标。此外，夜间 SpO 2N 增加失败可能表明适应不足。尽管夜间 SpO 2N 增加的潜在机制尚不清楚，但 SpO 2N 测量的时间显然对其解释至关重要。最后，我们的研究说明了通气适应在数周内的详细影响。