不同体位肺保护通气方式对肺内/外源性急性呼吸窘迫综合征犬肾上腺髓质素的影响

Effects of lung protective ventilation in prone or supine position on inhibiting adrenomedulin release in acute respiratory distress syndrome caused by pulmonary and extrapulmonary insults in dog

目的观察在仰卧位和俯卧位条件下小潮气量+呼气末正压(PEEP)通气对急性呼吸窘迫综合征(ARDS)模型犬肺不同部位(肺上区肺尖叶、肺下区腹侧肺心叶和肺下区背侧肺膈叶)支气管肺泡灌洗液(BALF)中肾上腺髓质素(ADM)的作用,以评价不同体位肺保护通气方式对肺内/外源性ARDS(ARDSp/ARDSexp)的抗炎作用机制。方法健康雄性杂种犬24只,随机分为ARDSp仰卧位通气组、俯卧位通气组以及ARDSexp仰卧位通气组、俯卧位通气组,每组6只。静脉注射油酸制备ARDSexp动物模型;气管内注入十六烷磺基丁二酸钠盐制备ARDSp动物模型。动态观察不同卧位条件下小潮气量+PEEP对ARDS模型犬氧合指数和肺不同部位BALF中ADM的变化。结果肺损伤后ARDS犬氧合指数明显下降;ARDSp模型犬肺尖叶和肺心叶BALF中ADM水平明显高于ARDSexp模型;俯卧位条件下肺保护性通气对ARDS模型犬具有更好的治疗效果,氧合指数改善更为明显,ADM释放受到抑制。结论ARDSexp和ARDSp对肺不同部位ADM释放的影响具有明显差异;俯卧位+小潮气量+PEEP通气模式对ARDSexp和ARDSp均具有良好的治疗效果。

Objective To investigate the changes in adrenomedulin release in bronchial alveolar lavage fluid (BALF) from different lung areas in acute respiratory distress syndrome (ARDS) of produced dogs, by pulmonary and extrapulmonary causes, with low tidal volume and positive end expiratory pressure (PEEP) treatment under supine and prone position. Methods Twentyfour male mongrel dogs were randomly divided into ARDSp (ARDS caused by pulmonary causes) supine group, ARDSp prone group, ARDSexp (ARDS caused by extrapulmonary causes) supine group, and ARDSexp prone group. A detergent to cause lung injury in ARDSp dogs, and intravenous oleic acid was given in ARDSexp dogs. The results of adrenomedulin in different areas of dog′s lung (upper lobe, middle lobe, and lower lobe) and arterial blood gas under lung protective ventilation treatment were measured. Results After lung injury, the arterial oxygenation index was lowered, and the levels of adrenomedulin in the upper lobe and middle lobe of ARDSp dogs were higher than that of ARDSexp dogs. After receiving low tidal volume and PEEP ventilation, the conditions of all the dogs were gradually getting ameliorated, and prone position ventilation gave better effects on lung injury dogs by inhibiting adrenomedulin release. Conclusion There are statistical differences in adrenomedulin release in different lung areas between ARDSp dogs and ARDSexp dogs, and in both ARDSexp dogs and ARDSp dogs low tidal volume and PEEP treatment under prone position ventilation give better results compared to supine position.