Warriner C B, Brooks L, Pare P D
Can Anaesth Soc J. 1981 Sep;28(5):436-41. doi: 10.1007/BF03010352.
The effects of acid aspiration on lung mechanics, gas exchange, haemodynamics and lung water, and their modification by nebulized dexamethasone were studied in 10 dogs. Each dog received 0.1 N HCl pH of 1.0 (15 ml/l vital capacity), instilled down the tracheal tube. PEEP 0.98 kPa (10 cm H2O) was introduced 20 minutes after aspiration and was continued until the completion of experiment. Treated animals (N = 5) received dexamethasone 5 mg . kg-1 by continuous nebulization over a two hour period starting 20 minutes after aspiration. Untreated (N = 5) animals received nebulized saline. Measurements were taken before aspiration and at 20 minutes 2.5 and 5.0 hours after aspiration. Red blood cells labelled with 51Cr were injected before sacrifice. After sacrifice multiple lung samples were taken for measurement of pulmonary extravascular water (PEW) by the gravimetric technique. Acid aspiration caused significant changes in lung volumes, PaO2, and intrapulmonary shunt. Pulmonary extravascular water was 6.16 +/- 0.93 ml/g dry tissue in treated and 6.47 +/- 0.60 ml/g dry tissue in untreated animals. These results indicate the presence of severe pulmonary oedema. There were no significant differences in any measured parameter between treated and untreated animals. We conclude that nebulized dexamethasone is of no value in treatment of the acute changes induced by acid aspiration.
在10只犬中研究了酸误吸对肺力学、气体交换、血流动力学和肺水的影响，以及雾化地塞米松对这些影响的改善作用。每只犬经气管插管注入0.1N HCl（pH 1.0，15ml/肺活量）。误吸后20分钟开始给予呼气末正压（PEEP）0.98kPa（10cmH₂O），并持续至实验结束。治疗组动物（n = 5）在误吸后20分钟开始，在两小时内持续雾化给予地塞米松5mg·kg⁻¹。未治疗组动物（n = 5）雾化给予生理盐水。在误吸前、误吸后20分钟、2.5小时和5.0小时进行测量。在处死前注射用⁵¹Cr标记的红细胞。处死动物后，采集多个肺样本，采用重量法测量肺血管外水（PEW）。酸误吸导致肺容积、动脉血氧分压（PaO₂）和肺内分流发生显著变化。治疗组动物肺血管外水为6.16±0.93ml/g干组织，未治疗组为6.47±0.60ml/g干组织。这些结果表明存在严重肺水肿。治疗组和未治疗组动物在任何测量参数上均无显著差异。我们得出结论，雾化地塞米松对治疗酸误吸引起的急性变化无价值。
