吸氧排氮对家兔低气压暴露时气泡产生的影响

目的 探讨不同时间的吸氧排氮方案对高空减压病的预防效果。方法 24只家兔随机分为对照组、吸氧排氮30、60和120min组4组。麻醉后行机械通气，分别吸氧排氮0、30、60和120min后上升至11000m停留30min，用超声多普勒技术检测气泡产生情况。结果 高空减压时气泡首次检出时间随着吸氧排氮时间的增加而延长，吸氧排氮60min和120min组家兔气泡首次检出时间较对照组显著延长(P＜0．01)，气泡首次检出时间与吸氧排氮时间呈正相关关系(P＜0．01)；累积气泡数随着吸氧排氮时间的增加而减少，吸氧排氮60min和120min组家兔累积气泡数较对照组显著减少(P＜0．01)，累积气泡数与吸氧排氮时间呈负相关关系(P＜0．01)。结论 吸氧排氮60min和120min两种方案可以显著减少兔由地面上升到11000m高空减压时气泡的产生。

Effects of Denitrogenation on Bubble Formation during Decompression in Rabbits

Objective To explore the effect of different degrees of denitrogenation on decompression sickness. Method Twenty-four rabbits were randomly divided into control group, 100% oxygen inhalation 30 min group, 60 min group and 120 min group. The rabbits were anesthetized and ventilated by mechanical ventilator. After 0, 30, 60 and 120 min of denitrogenation by inhalation of 100% oxygen, the rabbits were exposed to 11 000 m for 30 min. The gas bubbles generated in the body of rabbits were detected and monitored by a Doppler ultrasound detector over the precordium. Result Time to bubble appearance increased with time of 100% oxygen inhalation during altitude decompression. As compared with the control group, time to bubble appearance lengthened significantly in 100% oxygen inhalation 60 min and 120 min groups (P<0.01). Time to bubble appearance was positively correlated with time of 100% oxygen inhalation (P<0.01). Accumulative number of bubbles decreased with the time of 100% oxygen inhalation. As compared with the control group, accumulative number of bubbles decreased significantly in 100% oxygen inhalation 60 min and 120 min groups (P<0.01). Accumulative number of bubbles was negatively correlated with time of 100% oxygen inhalation (P<0.01). Conclusion Denitrogenation by inhalation of 100% oxygen for 60 min and 120 min may reduce the generation of gas bubbles in rabbits when decompressed to an altitude of 11 000 m.