胸段硬膜外阻滞对油酸诱发猪急性肺损伤时炎性反应的影响

目的 观察胸段硬膜外阻滞对油酸诱发猪急性肺损伤(ALI)时炎性反应的影响.方法 家猪14只,体重30～35kg,随机分为2组(n=7):对照组(C组)及硬膜外阻滞组(TEB组).于T3,4硬膜外置管后,采用静脉输注油酸的方法 制备ALI模型.ALI模型制备成功后,TEB组硬膜外注射0.25%罗哌卡因5ml,随后以2ml/h速率持续输注4 h,C组给予等容量生理盐水.分别于输注油酸前即刻、ALI模型制备成功后即刻、硬膜外给药1、2、3和4 h时测定PaO2.于硬膜外给药4 h时处死动物,行右侧支气管肺泡灌洗,计数支气管肺泡灌洗液(BALF)中细胞总数,计算中性粒细胞(PMN)百分比及PMN凋亡率;取左肺组织,测定总肺水量(TLW)及血管外肺水量(EVLW),并观察肺组织病理学结果 .结果 与C组比较,TEB组BALF中细胞总数、PMN百分比、TLW及EVLW均降低,PaO2和PMN凋亡率升高(P＜0.05或0.01).TEB组肺组织病理学损伤程度较C组减轻.结论 胸段硬膜外阻滞可减轻猪ALI时肺组织的炎性反应.

Influence of thoracic epidural blockade on pulmonary inflammatory response in a piglet model of oleic acid-induced acute lung injury

Objective To investigate the influence of thoracic epidural blockade(TEB)on the pulmonary inflammatory response in a piglet model of oleie acid-induced acute lung injury(ALI).Methods Fourteen piglets of both sexes weighing 30-35 kg were randomly divided into 2 groups(n=7 each):I control group(C)and Ⅱ TEB group.The animals were anesthetized with 2.5% pentothal sodium,intubated and mechanically ventilated.Right internal carotid cartery wag cannulated for BP monitoring and blood sampling.Right internal jugular vein was cannulated for oleic acid administration.Epidural catheter was placed at T3.4 interspace and was advanced cephalad for 5 cm in the epidural space.Correct placement was confirmed by X-ray.ALI was induced by administration of oleic acid 0.1 ml/kg in 20 ml which was infused via internal jugular vein at 40 ml/h until Pa02/Fi02≤200.Abolus of 0.25% ropivacaine 5 ml was administered followed by continuous infusion at 2 ml/h for 4 h via epidural catheter after induction of ALI in TEB group.In control group equal volume of normal saline was administered instead of0.25% ropivacaine.Pa02 was measul'cd before ALI was induced (baseline),immediately after ALI induction and at 1,2,3 and 4 h after epidural rpivacaine.The animals were killed at 4 h after epidural ropivacaine and the lungs were immediately removed.The right main bronchus was lavaged and broncho-alveolar lavage fluid(BALF) was collected for determination of the total number of cells,the percentage of PMN and the rate of PMN apoptosis.The left lung was removed for determination of total lung water(TLW)and extravascular lung water(EVLW)and microscopic examination.Results The total number of cells and the percentage of PMN in BALF and TLW and EVLW were significantly decreased while the rate of apoptosis of PMN and PaO2,were significantly increasedin TEB group as compared with control group(P