Hyldegaard O, Madsen J
Laboratory of Hyperbaric Medicine, Dept. of Anaesthesia 4132, HOC, Copenhagen Univ. Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, DK-Denmark.
J Appl Physiol (1985). 2007 Sep;103(3):757-62. doi: 10.1152/japplphysiol.00155.2007. Epub 2007 Jun 28.
The fate of bubbles formed in tissues during decompression to altitude after diving or due to accidental loss of cabin pressure during flight has only been indirectly inferred from theoretical modeling and clinical observations with noninvasive bubble-measuring techniques of intravascular bubbles. In this report we visually followed the in vivo resolution of micro-air bubbles injected into adipose tissue of anesthetized rats decompressed from 101.3 kPa to and held at 71 kPa corresponding to approximately 2.750 m above sea level, while the rats breathed air, oxygen, heliox (50:50), or heliox (80:20). During air breathing, bubbles initially grew for 30-80 min, after which they remained stable or began to shrink slowly. Oxygen breathing caused an initial growth of all bubbles for 15-85 min, after which they shrank until they disappeared from view. Bubble growth was significantly greater during breathing of oxygen compared with air and heliox breathing mixtures. During heliox (50:50) breathing, bubbles initially grew for 5-30 min, from which point they shrank until they disappeared from view. After a shift to heliox (80:20) breathing, some bubbles grew slightly for 20-30 min, then shrank until they disappeared from view. Bubble disappearance was significantly faster during breathing of oxygen and heliox mixtures compared with air. In conclusion, the present results show that oxygen breathing at 71 kPa promotes bubble growth in lipid tissue, and it is possible that breathing of heliox may be beneficial in treating decompression sickness during flight.
潜水后减压至高空或飞行中因机舱压力意外丧失而在组织中形成的气泡命运，仅通过理论建模以及使用血管内气泡无创测量技术的临床观察进行间接推断。在本报告中，我们在视觉上追踪了注入麻醉大鼠脂肪组织中的微气泡在体内的消散情况。这些大鼠从101.3 kPa减压至71 kPa并保持在该压力，相当于海拔约2750米，同时大鼠呼吸空气、氧气、氦氧混合气（50:50）或氦氧混合气（80:20）。在呼吸空气时，气泡最初会生长30 - 80分钟，之后它们保持稳定或开始缓慢收缩。呼吸氧气会使所有气泡最初生长15 - 85分钟，之后它们会收缩直至消失不见。与空气和氦氧混合气呼吸相比，呼吸氧气时气泡的生长明显更大。在呼吸氦氧混合气（50:50）时，气泡最初生长5 - 30分钟，从那时起它们会收缩直至消失不见。在转换为呼吸氦氧混合气（80:20）后，一些气泡会轻微生长20 - 30分钟，然后收缩直至消失不见。与空气相比，呼吸氧气和氦氧混合气时气泡消失明显更快。总之，目前的结果表明，在71 kPa下呼吸氧气会促进脂质组织中气泡的生长，并且呼吸氦氧混合气可能对治疗飞行中的减压病有益。
