一个模型来模拟人类临床相关性缺氧
Summary
在人类缺氧模拟通常也被因吸入低氧气体混合物进行。在这项研究中，呼吸暂停潜水员被用来模拟人类动态缺氧。另外，在去饱和和再饱和动力学的生理变化与非侵入性工具，例如近红外光谱法（NIRS）和外围氧合饱和度（ 血氧饱和度）来评价。
Abstract
In case of apnea, arterial partial pressure of oxygen (pO2) decreases, while partial pressure of carbon dioxide (pCO2) increases. To avoid damage to hypoxia sensitive organs such as the brain, compensatory circulatory mechanisms help to maintain an adequate oxygen supply. This is mainly achieved by increased cerebral blood flow. Intermittent hypoxia is a commonly seen phenomenon in patients with obstructive sleep apnea. Acute airway obstruction can also result in hypoxia and hypercapnia. Until now, no adequate model has been established to simulate these dynamics in humans. Previous investigations focusing on human hypoxia used inhaled hypoxic gas mixtures. However, the resulting hypoxia was combined with hyperventilation and is therefore more representative of high altitude environments than of apnea. Furthermore, the transferability of previously performed animal experiments to humans is limited and the pathophysiological background of apnea induced physiological changes is poorly understood. In this study, healthy human apneic divers were utilized to mimic clinically relevant hypoxia and hypercapnia during apnea. Additionally, pulse-oximetry and Near Infrared Spectroscopy (NIRS) were used to evaluate changes in cerebral and peripheral oxygen saturation before, during, and after apnea.
Introduction
临床相关的急性缺氧和高碳酸血症伴大多见于阻塞性睡眠呼吸暂停综合征（OSAS），急性呼吸道阻塞或心肺复苏过程中。在OSAS等低氧条件的领域主要局限包括有关动物研究的病理生理学和人体模型是不存在1有限转让知识。模仿人体缺氧，缺氧的气体混合物迄今已使用2 – 7。然而，这些条件都比较有代表性的高海拔环境比，其中缺氧，在一般情况下，伴随的高碳酸血症的临床情况的。为了监测心脏骤停和复苏过程中的组织氧合，动物研究已经完成8探讨生理代偿机制。
窒息潜水员能够压低呼吸冲动运动员健康是受低动脉血氧饱和度9和增加的pCO 2 10,11诱发。我们以模仿急性缺氧和高碳酸血症相伴12临床情况调查呼吸暂停潜水员。该模型可用于评价临床设置，提高患者的OSAS或病理呼吸病症的病理生理学的了解，并揭示了新的可能性在呼吸暂停的情况下，研究的潜在计数器平衡机制。此外，不同的技术来检测缺氧人类可以在动态缺氧的情况下，可行性和准确性被测试存在于紧急情况下（ 即 ，气道阻塞，喉或无法插管，可以不透风的情况），或者以模拟在患者间歇性缺氧OSAS患者。
非侵入性的技术来检测缺氧在人中是有限的。外围脉搏血氧饱和度（SPO 2）预好客的认可工具TAL和医院设置，检测缺氧13。该方法是基于血红蛋白的光吸收。然而， 血氧饱和度测量被限制为外周动脉氧合并且不能在无脉性电活动（PEA）或集中最小循环14的情况下使用。与此相反，近红外光谱法可用于在实时的PEA中出血性休克或蛛网膜下腔出血15中，以评估脑组织氧饱和度（RSO 2）， – 19。它的使用在不断增加20和方法论研究显示血氧饱和度和RSO 2 3,4之间的正相关关系。
在这项研究中，我们提供了一个模型来模拟人类的临床相关缺氧并给出了一个一步一步的方法来比较外围脉搏血氧饱和度和NIRS在德和再饱和的情况下。通过在的情况下进行分析生理数据pnea，我们的反平衡机制的认识得以提高。
Protocol
Representative Results
Discussion
总呼吸暂停时间主要是由肺尺寸和每分钟的氧气消耗，并通过一个个人承受造成增加的pCO 2或减小PO 2的呼吸反射能力的影响。呼吸暂停潜水员培训，以最大限度地发挥他们的屏气时间，用于在最大吸气这样做。因此，时间直到缺氧是个体之间可检测的不同，并取决于受试者的身体状况和训练状态，甚至可能通过他们的日常状态和意愿而改变承受呼吸反射。可以通过协议步骤的详细…
Disclosures
The authors have nothing to disclose.
Acknowledgements
Special thanks to all volunteers who participated in the original study. The work of L. Eichhorn was supported through a scholarship of the Else-Kröner-Fresenius Foundation. The authors would like to thank Springer, Part of Springer Science+Business Media, for copyright clearance (License Number 3894660871180) and the kind permission of reusing previously published data.
Materials
| SpO2 | Dräger Medical AG&CO.KG | SHP ACC MCABLE-Masimo Set | peripheral SpO2-Monitoring |
| Non Invasive Blood Pressure (NIBP) | Dräger Medical AG&CO.KG | NIBP cuff M+, MP00916 | |
| Electrocardiographic (ECG) | Dräger Medical AG&CO.KG | Infinity M540 Monitor | ECG monitoring |
| Docking station | Dräger Medical AG&CO.KG | M500 Docking Station | connection of M540 to laptop |
| NIRS | NONIN Medical’s EQUANOX | Model 7600 Regional Oximeter System | measuring of cerebral and tissue oxygenation |
| NIRS diodes | EQUANOX Advance Sensor | Model 8004CA | suited for measuring cerebral and somatic oxygen-saturation |
| Laptop | |||
| DataGrabber | Dräger Medical AG&CO.KG | DataGrabber v2005.10.16 | software to synchronize M540 with laptop |
| eVision | Nonin Medical. Inc. | Version 1.3.0.0 | software to synchronize NONIN with laptop |
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