去甲肾上腺素对山羊急性呼吸窘迫综合征吸入一氧化氮疗效及肺损伤的影响

目的：观察去甲肾上腺素(NE)对山羊感染性急性呼吸窘迫综合征(ARDS)吸入一氧化氮(NO)疗效(血流动力学和肺氧合)及肺损伤的影响。 方法： 静脉注入小剂量内毒素诱导山羊感染性ARDS模型6只，吸入40×10－6 NO 30 min后，联合静脉泵入NE 0.5 μg·kg-1·min-1。通过股动脉、Swan-Ganz导管分别取动脉血、混合静脉血分析血气，测定或计算基础、ARDS、NO吸入治疗30 min和联合NE静脉泵入治疗30 min后血流动力学和肺氧合参数，直视下取右下肺组织，光镜观察肺损伤变化。 结果： NO吸入治疗显著降低ARDS山羊的平均肺动脉压(MPAP，P<0.01)，增加动脉氧分压(PaO2，P<0.01)、减少肺泡动脉氧分压差［P(A-a)O2］和肺内分流率(Qs/Qt，均P<0.05)，基本不影响混合静脉血氧分压(PvO2)；联合NE静脉泵入不影响吸入NO后降低的MPAP，增加吸入NO后升高PaO2(P<0.05)，降低NO吸入后减少的P(A-a)O2和Qs/Qt(均P<0.05)，亦不影响PvO2升高吸入NO后无改变的平均动脉压(P<0.05)；吸入NO及联合应用NE治疗均不改变ARDS山羊的心排血量；吸入NO不能减轻ARDS肺损伤，联合小剂量NE静脉泵入则能减轻。 结论： 静脉注入小剂量NE增强吸入NO改善感染性ARDS肺氧合的疗效并减轻肺损伤。

Effects of norepinephrine on lung injury in acute respiratory distress syndrome goats with inhaled nitric oxide

AIM: To observe the effects of norepinephrine (NE) on the cardiopulmonary and lung injury in goats with acute respiratory distress syndrome (ARDS) induced by endotoxin. METHODS: A model of septic ARDS was induced by intravenous infusion of low dose endotoxin in six goats. Then 40×10-6 NO inhalation was applied to the animals. After 30 min, combined intravenous infusion of NE at concentration of 0.5 mg·kg-1·min-1 was conducted. The dynamic changes in gas exchange and hemodynamics were measured with the aid of Swan-Ganz catheter. Arterial blood gas analysis before and after the onset of ARDS, 30 min after NO inhalation and combined NE was detected. Histology of the lung was also observed. RESULTS: Inhalation of NO rapidly reduced mean pulmonary arterial pressure (MPAP), increased PaO2, decreased P(A-a)O2 and Qs/Qt in septic ARDS goats. These decrease and increase were more significant than those in NO inhaled alone when animals received NE. The combination of NO inhalation and NE injection resulted in increase in mean arterial pressure. NO inhalation did not ameliorate lung injury and combined NE intravenous injection ameliorated lung injury. CONCLUSION: Injection of low dose norepinephrine improves the beneficial effects of inhaled nitric oxide on lung gas exchange and ameliorates lung injury in goats with acute respiratory distress syndrome induced by endotoxin.