Mayo Clinic, Aerospace Medicine and Vestibular Research Laboratory (AMVRL), Scottsdale, AZ, USA.
Mayo Clinic Alix School of Medicine, Scottsdale, AZ, USA.
Physiol Rep. 2020 Jul;8(14):e14513. doi: 10.14814/phy2.14513.
Oxygen is viewed in medicine as the sole determinant of tissue oxygenation, though carbon dioxide homeostasis is equally important and clinically often ignored. The aims of this study were as follows: (a) to examine the effects of different acute hypoxic conditions on partial pressure of arterial oxygen ( ), arterial oxygen saturation of hemoglobin ( ), and regional cerebral saturation of hemoglobin (rSO ); and (b) to evaluate supplemental CO as a tool to improve oxygenation in acutely hypoxic individuals. We hypothesized that exposure to gas mixtures with added CO would improve oxygenation in hypoxic human subjects. Twenty healthy subjects were exposed to 5-min intervals of two gas mixtures: hypoxic gas mixture containing 8% oxygen, and a CO -enriched mixture containing 8% oxygen plus either 3% or 5% CO . Ten subjects received the 3% CO -enriched mixture, and the remaining 10 subjects received the 5% CO -enriched mixture. The order of exposure was randomized. Blood gases, pulse oximetry, end-tidal CO , and cerebral oximetry were measured. Compared to the purely hypoxic gas group, was increased in the 3% and 5% CO -enriched groups by 14.9 and 9.5 mmHg, respectively. Compared to pure hypoxia, was increased in the 3% and 5% CO -enriched groups by 16.8% and 12.9%, respectively. Both CO -enriched gas groups had significantly higher end-exposure rSO and recovered to baseline rSO within 1 min, compared to the pure hypoxic gas group, which returned to baseline in 5 min. These results suggest that in acutely hypoxic subjects, CO supplementation improves blood oxygen saturation and oxygen tension as well as cerebral oxygenation measures.
在医学中，氧气被视为组织氧合的唯一决定因素，尽管二氧化碳动态平衡同样重要，但在临床上经常被忽视。本研究的目的如下：（a）研究不同急性低氧条件对动脉血氧分压（ ）、血红蛋白动脉血氧饱和度（ ）和局部脑血红蛋白饱和度（rSO ）的影响；（b）评估补充 CO 作为改善急性低氧个体氧合的工具。我们假设，暴露于添加 CO 的气体混合物中会改善低氧血症患者的氧合。20 名健康受试者暴露于两种气体混合物 5 分钟：含有 8%氧气的低氧气体混合物，以及含有 8%氧气和 3%或 5% CO 的 CO 富集混合物。10 名受试者接受 3% CO 富集混合物，其余 10 名受试者接受 5% CO 富集混合物。暴露顺序是随机的。测量血气、脉搏血氧饱和度、呼气末 CO 和脑氧饱和度。与纯低氧气体组相比，3%和 5% CO 富集组的 分别增加了 14.9 和 9.5mmHg。与纯低氧相比，3%和 5% CO 富集组的 分别增加了 16.8%和 12.9%。与纯低氧气体组相比，两种 CO 富集气体组的终末暴露 rSO 更高，且在 1 分钟内恢复至基线 rSO ，而纯低氧气体组在 5 分钟内恢复至基线 rSO 。这些结果表明，在急性低氧受试者中，CO 补充可改善血氧饱和度和氧分压以及脑氧合测量。
