Extreme Environments Laboratory, School of Sport, Health and Exercise Science, University of Portsmouth, Portsmouth, United Kingdom.
Network Physiology Laboratory, UCL Division of Medicine, University College London, London, United Kingdom.
High Alt Med Biol. 2020 Mar;21(1):76-83. doi: 10.1089/ham.2019.0092. Epub 2020 Feb 18.
The study is the first to evaluate the effects of graded normobaric hypoxia on SpO variability in healthy individuals. Twelve healthy males (mean [standard deviation] age 22 [4] years) were exposed to four simulated environments (fraction of inspired oxygen [O]: 0.12, 0.145, 0.17, and 0.21) for 45 minutes, in a balanced crossover design. Sample entropy, a tool that quantifies the irregularity of pulse oximetry fluctuations, was used as a measure of SpO variability. SpO entropy increased as the O decreased, and there was a strong significant negative correlation between mean SpO and its entropy during hypoxic exposure ( = -0.841 to -0.896, < 0.001). In addition, SpO sample entropy, but not mean SpO, was correlated ( = 0.630-0.760, < 0.05) with dyspnea in O 0.17, 0.145, and 0.12 and importantly, SpO sample entropy at O 0.17 was correlated with dyspnea at O 0.145 ( = 0.811, < 0.01). These findings suggest that SpO variability analysis may have the potential to be used in a clinical setting as a noninvasive measure to identify the negative sequelae of hypoxemia.
这项研究首次评估了分级常压低氧对健康个体 SpO 变异性的影响。12 名健康男性（平均[标准差]年龄 22[4]岁）接受了四种模拟环境（吸入氧分数[O]：0.12、0.145、0.17 和 0.21）的 45 分钟暴露，采用平衡交叉设计。样本熵，一种量化脉搏血氧仪波动不规则性的工具，被用作 SpO 变异性的测量指标。随着 O 的降低，SpO 熵增加，并且在低氧暴露期间，平均 SpO 与其熵之间存在强烈的显著负相关（ = -0.841 至 -0.896， < 0.001）。此外，SpO 样本熵，而不是平均 SpO，与 O 0.17、0.145 和 0.12 时的呼吸困难相关（ = 0.630-0.760， < 0.05），重要的是，O 0.17 时的 SpO 样本熵与 O 0.145 时的呼吸困难相关（ = 0.811， < 0.01）。这些发现表明，SpO 变异性分析可能具有作为一种非侵入性措施在临床环境中识别低氧血症的不良后果的潜力。
