在健康人群中由负压呼吸诱导的血液动力学参数的振荡
Aerospace medicine and human performance
|May 25, 2024
概括
吸气时的负压呼吸 (NPBin) 没有改变平均血液动力学值,但产生了呼吸同步振荡. 这种方法可能有助于抵消在太空飞行期间液体向头部移动.
科学领域:
- 心血管生理学心血管生理学
- 呼吸系统生理学 呼吸系统生理学
- 太空医学 太空医学
背景情况:
- 负压呼吸 (NPB) 涉及在吸气过程中降低呼吸道压力,而不影响干压力.
- NPB,特别是负压呼吸灵感 (NPBin),正在被探索作为一个对抗措施,在太空飞行期间的 Cephalad 流体移动.
- 了解NPBin对血液循环的影响,特别是呼吸同步的血液动力学振荡,对于其应用至关重要.
研究的目的:
- 研究NPBin对健康人类心血管循环的影响.
- 分析与呼吸同步的血液动力学参数中的NPBin诱导的振荡.
- 评估NPBin在缓解脑流体再分配方面的潜力.
主要方法:
- 八名健康的成年男性参与了NPBin和对照试验.
- 试验对象被置于仰卧和俯卧 (-8°) 的位置,以模拟微重力流体的移动.
- 血液动力学参数是用Finometer测量,脑血量变化通过电阻评估在20分钟的NPBin会话 (-20厘米H2O稀缺) 期间的电阻.
主要成果:
- 平均血液动力学参数显示最小的变化,但NPBin诱导了平均动脉压,中风体积和心率的显著呼吸同步振荡.
- 这些振荡的峰值到峰值幅度为4±1 mmHg (MAP),7±3 mL (SV) 和4±1 bpm (HR).
- 吸入时头部电阻增加,与正常呼吸相比,NPBin的增加是正常呼吸的三倍,这表明大脑血液体积减少.
结论:
- 对NPBin诱导的振荡的分析提供了比单独的平均值更深入的见解.
- 在吸气过程中,NPBin会导致左心室中风体积和动脉压的短暂下降,随后补偿性增加.
- NPBin有效地促进了身体液体从头部重新分配.
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