Chopp C S, Bomar J B, Harding R M, Holden R D, Bauer D H
Crew Technology Division, USAF School of Aerospace Medicine, Brooks AFB, TX 78235-5301.
Aviat Space Environ Med. 1990 Jul;61(7):604-8.
Interest in Molecular Sieve Oxygen Generation Systems (MSOGS) for use in military aircraft has demonstrated a need to study physiological effects of MSOGS product gas in the worst case scenario, a rapid decompression (RD). In this paper we report the heart rate (HR) response to positive pressure breathing (PPB) during and after RD from 6,096 to 15,239 m (20,000 to 50,000 ft) in a hypobaric chamber while breathing gas mixtures that simulate the product gas from MSOGS. Interbeat (R-R) intervals were recorded in 10 subjects while they breathed either Aviators' Breathing Oxygen (ABO), that is 99.5% oxygen, or 93% oxygen at two regulator settings: dilution and non-dilution. Additional experimental profiles on six subjects isolated the effects of hypoxia, anxiety, and PPB on HR changes after RD. Anxiety appeared to have the greatest effect. Most of the subjects showed increased HR and reduced HR variability after the onset of pressure breathing (immediately after decompression). As the exposure continued, HR variability increased as the HR began to decline. No consistent change in the HR response could be attributed to the modest increase in hypoxia produced by substitution of 93% oxygen for ABO.
对用于军用飞机的分子筛制氧系统（MSOGS）的关注表明，有必要在最坏的情况下，即快速减压（RD）时，研究MSOGS产出气体的生理效应。在本文中，我们报告了在低压舱内，从6096米至15239米（20000至50000英尺）进行快速减压期间及之后，受试者呼吸模拟MSOGS产出气体的混合气体时，其心率（HR）对正压呼吸（PPB）的反应。在10名受试者呼吸两种调节器设置（稀释和不稀释）下的航空呼吸用氧（ABO，即99.5%的氧气）或93%的氧气时，记录了他们的心跳间期（R-R间期）。对6名受试者进行的额外实验分析，分离出了缺氧、焦虑和PPB对快速减压后心率变化的影响。焦虑似乎影响最大。大多数受试者在压力呼吸开始后（减压后立即）心率增加且心率变异性降低。随着暴露持续，随着心率开始下降，心率变异性增加。用93%的氧气替代ABO所产生的适度缺氧，并未导致心率反应出现一致变化。
