Windsor Jeremy S, Rodway George W
Centre for Aviation, Space and Extreme Environment Medicine, University College London, London, UK.
Aviat Space Environ Med. 2007 Apr;78(4):426-9.
This study examines the effect of supplemental oxygen on acclimatized mountaineers at high altitude during rest and submaximal exercise.
Three healthy, acclimatized participants undertook nine periods of data collection lasting 10 min each over 2 consecutive days at 5700 m. These occurred at rest and exercise (40 and 80 W), breathing ambient air or supplemental oxygen (2 and 4 L m min') through an open-circuit breathing system.
As minute ventilation increased during exercise, the fraction of inspired oxygen (FIO2) fell from 0.31 at rest to 0.23 with 2 L x min(-1) of oxygen and from 0.36 to 0.26 with 4 L x min(-1). Oxygen at both flow rates resulted in a significant increase in the arterial blood saturation of oxygen (SaO2) (Rest: 79% to 96% to 97%; 40 W: 80% to 95% to 97%; 80 W: 76% to 94% to 98%) and reduction in respiratory rate (RR) (Rest: 28 to 22 to 24; 40 W: 36 to 25 to 25; 80 W: 41 to 26 to 26). Tidal volume (VT, ml x s(-1)) was found to increase with the addition of oxygen (Rest: 959 to 844 to 969; 40 W: 1393 to 1834 to 1851; 80 W: 1558 to 2105 to 2215) and resulted in a non-significant reduction in minute ventilation (VE, L) (Rest: 25 to 17 to 21; 40 W: 46 to 45 to 43; 80 W: 61 to 51 to 53). No significant changes in heart rate were observed when oxygen was used (Rest: 78 to 62 to 71; 40 W: 90 to 91 to 96; 80 W: 105 to 102 to 101).
An open-circuit breathing system may increase SaO2 and reduce RR in acclimatized mountaineers during rest and sub-maximal exercise at 5700 m, though further research is needed to confirm this.
本研究探讨了补充氧气对适应高原环境的登山者在休息和次最大运动时的影响。
三名健康且适应高原环境的参与者在5700米的高度连续两天进行了九个阶段的数据收集，每个阶段持续10分钟。这些阶段分别在休息和运动（40瓦和80瓦）时进行，通过开路呼吸系统呼吸环境空气或补充氧气（2升/分钟和4升/分钟）。
随着运动过程中每分通气量增加，吸入氧分数（FIO2）从休息时的0.31降至吸氧2升/分钟时的0.23，以及从0.36降至吸氧4升/分钟时的0.26。两种流速的氧气均导致动脉血氧饱和度（SaO2）显著增加（休息：从79%升至96%再升至97%；40瓦运动：从80%升至95%再升至97%；80瓦运动：从76%升至94%再升至98%），呼吸频率（RR）降低（休息：从28次降至22次再降至24次；40瓦运动：从36次降至25次再降至25次；80瓦运动：从41次降至26次再降至26次）。潮气量（VT，毫升/秒）随着氧气的补充而增加（休息：从959毫升/秒升至844毫升/秒再升至969毫升/秒；40瓦运动：从1393毫升/秒升至1834毫升/秒再升至1851毫升/秒；80瓦运动：从1558毫升/秒升至2105毫升/秒再升至2215毫升/秒），并导致每分通气量（VE，升）出现不显著的降低（休息：从25升降至17升再降至21升；40瓦运动：从46升降至45升再降至43升；80瓦运动：从61升降至51升再降至53升）。使用氧气时未观察到心率有显著变化（休息：从78次/分钟降至62次/分钟再升至71次/分钟；40瓦运动：从90次/分钟升至91次/分钟再升至96次/分钟；80瓦运动：从105次/分钟降至102次/分钟再升至101次/分钟）。
开路呼吸系统可能会增加适应高原环境的登山者在5700米休息和次最大运动时的SaO2并降低RR，不过仍需进一步研究来证实这一点。
