Baranov V M, Popova Iu A, Kovalev A S, Baranov M V
Aviakosm Ekolog Med. 2011 Jul-Aug;45(4):35-8.
The investigation was aimed at studying the mechanisms for change in the respiration center sensitivity in consequence of 21-hr bed rest with head-end tilted at -15 degrees combined with liquid loss (lasix, 20 ml) and recovery (IV infucol and glucose). Time of maximal breath-holding, capillary and venous O2 and CO2 pressure values were measured in the baseline data collection period, during and shortly after BR. Data analysis showed that extension of the maximal breath-holding time both during inspiration and expiration was statistically significant in the initial 10 minutes of tilting. Comparison of the breath-holding test data between the experimental series demonstrated that infusion of equally glucose and infucol did not affect voluntary apnea during inspiration or expiration. From BR hour 17, partial pressure of venous O2 showed a significant rise, while venous CO2 pressure decreased, also significantly. It is hypothesized that degradation of the respiration center sensitivity was connected most likely with blood pooling in the upper body and altered pressure on the baroreceptors.
该研究旨在探讨因头部向下倾斜15度卧床21小时并伴有液体丢失（速尿20毫升）及恢复过程（静脉输注羟乙基淀粉和葡萄糖）而导致呼吸中枢敏感性变化的机制。在基线数据收集期、卧床期间及卧床后不久，测量了最大屏气时间、毛细血管及静脉血氧和二氧化碳压力值。数据分析表明，在倾斜开始的最初10分钟内，吸气和呼气时最大屏气时间的延长具有统计学意义。各实验组间屏气测试数据的比较表明，输注等量的葡萄糖和羟乙基淀粉对吸气或呼气时的自主呼吸暂停无影响。从卧床第17小时起，静脉血氧分压显著升高，而静脉血二氧化碳分压也显著降低。据推测，呼吸中枢敏感性的降低很可能与上半身血液淤积及压力感受器压力改变有关。
