异氟烷预处理对心肺转流术后早期肺损伤的影响

Effects of isoflurane preconditioning against cardiopul monary bypass-induced early injury of lungs

目的观察异氟烷预处理对心肺转流术（cardiopulmonary bypass，CBP）后早期肺损伤的影响。方法择期CBP下行心脏瓣膜置换术的病人16例，随机分为对照组（C组）和异氟烷组（I组），每组8例。两组均采用静脉注射芬太尼、咪唑安定、维库溴铵维持麻醉。I组分别在CPB开始前吸入异氟烷至呼气末浓度达1．3MAC后维持时间不少于30min，洗脱15min，而C组只吸入纯氧。分别于麻醉诱导后10min（T1），上下腔静脉开放30min（T2），上下腔静脉开放180min（T3）采桡动脉血测定血清中的肿瘤坏死因子啦（TNF电）、P-选择素（P-selectin）、丙二醛（MDA）浓度及髓过氧化物酶（MPO）活性，同时血气分析并计算呼吸指数（RI）。在关胸前每组取2例病人少量肺组织观察缝隙连接蛋白Cx43的表达及肺组织病理学检查。结果两组CBP后TNF-α、P-selectin、MDA、MPO水平比CBP前均显著升高（P〈0．05），其中P-selectin随时间推移升高更明显（P〈0．01），MPO随时间推移迅速恢复至CBP前水平。TNF-α、MDA水平CBP后I组比C组升高更明显（P〈0．05）；RI仅C组CBP后显著升高（P〈0．01），I组升高不明显。肺缝隙连接蛋白Cx43分布与着色两组无统计学差异。肺组织病理检查两组均可见肺泡结构破坏及渗出液，肺泡腔PMNS及红细胞浸润。结论异氟烷预处理抑制CBP后肺炎症反应，减轻肺组织的氧化应激反应，对CBP后早期肺损伤具有一定的保护作用。

Objective To observe the effects of isoflurane preconditioning against cardiopulmonary bypass （CBP）-induced early injury of lungs. Methods Sixteen patients undergone cardiac valve replacement were randomly divided into control group （group C, n=8） or isoflurane group （group I, n=8）. Midazolam, fentanyl and vecuronium were used to maintain anesthesia. Isoflurane was inhaled for at least 30 min before CBP and then eluted out in group I, while only pure oxygen was inhaled in group C. Serum TNF-α, P-selectin, MDA and myeloperoxidase （MPO） were measured and respiratory index （RI, PA-aDO2/PaO2） was calculated according to blood gas analysis 10 min after anesthesia induction （T1）, 30 min （T2） and 180 min （T3） after vena cava opened, respectively. Before chest closure a bit of lung tissue was taken for detection of gap junction protein 43 （Cx43） and pathological examination. Results Serum TNF-α, P-selectin, MDA, MPO and RI significantly increased after CPB （T2-3） in both groups （P〈0.05-0.01）, with less increasing extent in group I than in group C. There were no differences in distribution, colorful gap junction of lungs and CX43 expression in both groups. Pathological examination showed obvious edema in alveolar space, destroyed alveolar structure, severe neutrophil accumulation and erythrocyte infiltration in both groups. Conclusion Isoflurane preconditioning attenuates the oxidative stress response and lung inflammatory reaction, exerting protection of lungs against CBP-induced early injury.