Meier G H, Wood W J, Symbas P N
Ann Thorac Surg. 1979 Feb;27(2):161-8. doi: 10.1016/s0003-4975(10)63260-2.
This study evaluates the role of increased intratracheal pressure in developing systemic air embolization. Twenty healthy mongrel dogs were monitored for air embolization, both by means of an extracorporeal arteriovenous shunt constructed from transparent plastic tubing for visualization of air emboli and by means of a Doppler flow probe implanted at the root of the aorta. Systemic arterial, left atrial, intratracheal, and intrapleural pressures were recorded. In 10 of the dogs, a penetrating wound of the lung 1 cm wide by 4 cm deep was produced; in 5 the chest was left open and in 5 the chest was closed. The remaining 10 dogs served as controls (with no wound of the lung); in 5 the chest was left open and in the other 5 the chest was closed. No air embolization occurred in any animals at intratracheal pressures less than 65 mm Hg. However, systemic air embolization occurred in every dog in all groups upon hyperinflation of the lung above 65 mm Hg. The control groups differed from the groups with penetrating wound only in the quantity of embolized air. This study suggests that hyperinflation of the lung to an intratracheal pressure above 65 mm Hg results in systemic air embolization and that the presence of a penetrating wound of the lung at such intratracheal pressure predisposes to a greater quantity of air embolization.
本研究评估气管内压力升高在全身性空气栓塞形成中的作用。通过用透明塑料管构建的体外动静脉分流装置来观察空气栓子，以及通过植入主动脉根部的多普勒血流探头，对20只健康杂种犬进行空气栓塞监测。记录全身动脉压、左心房压、气管内压和胸腔内压。10只犬造成1厘米宽、4厘米深的肺穿透伤；5只犬胸部敞开，5只犬胸部闭合。其余10只犬作为对照（无肺损伤）；5只犬胸部敞开，另外5只犬胸部闭合。气管内压力低于65毫米汞柱时，所有动物均未发生空气栓塞。然而，当肺过度充气使气管内压力高于65毫米汞柱时，所有组的每只犬均发生全身性空气栓塞。对照组与有穿透伤的组之间的差异仅在于栓塞空气的量。本研究表明，肺过度充气使气管内压力高于65毫米汞柱会导致全身性空气栓塞，并且在这种气管内压力下存在肺穿透伤会使空气栓塞量更大。
