外源性一氧化氮及氦-氧混合气对重症哮喘作用的实验研究

本研究的目的即通过动物实验 ,观察一氧化氮作为支气管扩张剂解除气道痉挛的作用及对肺内气体交换的影响 ,以及同时吸入一氧化氮和氦 氧混合气对哮喘的作用。方法 :选取 12只雄性杂种犬采用交叉设计、自身对照的方法进行实验 ,采用向气管内注入乙酰甲胆碱的方法使气道平滑肌痉挛。气道激发后观察吸入10 0× 10 -6的一氧化氮以及同时吸入一氧化氮和氦 氧混合气对吸气阻力、肺动脉压和肺内气体交换的影响。结果 :气道激发后吸气阻力、肺动脉压显著增高 ,呼吸系有效顺应性和动脉血氧分压明显下降 ,动 静脉分流增加伴随二氧化碳潴留。吸入 10 0× 10 -6一氧化氮能够降低气道阻力及肺动脉压 ,但对有效肺顺应性、动 静脉分流、动脉血氧分压、二氧化碳分压的影响不大。然而将一氧化氮与氦 氧混合气混合同时吸入 ,与单纯吸入一氧化氮比较 ,气道阻力进一步下降 ,有效肺顺应性、动脉血氧分压明显增加 ,动 静脉分流和动脉血二氧化碳分压显著下降。结论 :吸入较高浓度的一氧化氮能够对抗由乙酰甲胆碱引起的气道痉挛以及由缺氧引起的肺动脉压增高 ,但不能明显改善肺内气体交换。同时吸入氦 氧混合气后不但能进一步的降低气道阻力 ,而且对呼吸系有效顺应性、动 静脉分流以及动脉血氧分压、二氧化碳分压有明显的改

The experimental research on inhaled nitric oxide and helium-oxygen mixture in the asthma-tic dog

Objective:To investigate the effect of Nitric Oxide (NO) as a bronchodilator on releasing bronchoconstriction and improving pulmonary gas exchange through the experimental research, and investigate the effect of inhaling NO and Helium Oxygen mixture (Heliox) simultaneously on asthmatic dogs. Methods:12 male mangles were included in this study. The bronchoconstriction was induced by intratracheal infusion of methacholine. Then the inspiratory resistance (Ri), the pulmonary artery pressure (Ppa), the effective respiratory system compliance (Ceff) and pulmonary gas exchange were monitored during inhaling 100 ppm NO or inhaling Heliox and NO simultaneously. Results:The RI and Ppa increased significantly after bronchospasm, whereas Ceff and PaO 2 decreased. At the same time the pulmonary shunt (Qs/Qt) and PaCO 2 were increased. Inhaling 100 ppm NO decreased Ri and Ppa, but did not improved Ceff, PaO 2, PaCO 2 and Qs/Qt. However inhaling NO and Heliox simultaneously decreased more Ri and Ppa, and improved more pulmonary gas exchange compared with inhaling NO. Conclusion:Inhalation of high concentration of NO can inverse partly the bronchospasm induced by methacholine in the dog, but not improve the gas exchange. However, inhaling Heliox not only decreases the resistance of airways, but also improves the gas exchange in the lung.