七氟醚预先给药对心脏瓣膜置换术患者心肌损伤的影响

Effects of sevoflurane pretreatment on myocardial injury in patients undergoing cardiac valve replacement with cardiopulmonary bypass

目的评价七氟醚预先给药对心脏瓣膜置换术患者心肌损伤的影响。方法拟行心脏瓣膜置换术的风湿性心脏病患者20例，性别不限，年龄〈60岁，NYHA心功能分级Ⅱ或Ⅲ级，采用随机数字表法，将其随机分为2组（n=10）：对照组（c组）和七氟醚组（s组）。S组于主动脉阻断前吸入七氟醚，维持呼气末浓度1．0％并持续30min。于切皮前、主动脉阻断即刻、主动脉开放即刻、主动脉开放后30min、术后2、6、12和24h时抽取中心静脉血样，测定血浆c附浓度、CK和CK-MB的活性；主动脉阻断前和开放后10min时分别取右心耳组织，采用透射电镜观察心肌细胞线粒体超微结构。结果与C组比较，s组于主动脉开放后30min、术后2、6、12和24h时血浆cTnI浓度降低，术后24h时血浆CK、CK—MB的活性下降（P〈0．05）；两组主动脉开放后心肌细胞线粒体均出现不同程度的肿胀，但s组轻于C组。结论七氟醚预先给药可减轻心脏瓣膜置换术患者的心肌损伤。

Objective To investigate the effects of sevoflurane pretreatment on the myocardial injury in patients undergoing cardiac valve replacement with cardiopulmonary bypass （CPB）. Methods Twenty NYHA class II or m patients, aged 〈 60 yr, undergoing cardiac valve replacement with CPB, were randomly divided into 2 groups （ n = 10 each） ： sevoflurane group （group S） and control group （group C）. The patients were premeditated with intramuscular morphine and scopolamine. Anesthesia was induced with iv injection of midazolam 0.05-0.08 mg/kg, fentanyl 10-15 ug/kg and pipecuronium 0.08-0.10 mg/kg. Anesthesia was maintained with intermittent iv boluses of midazolam, fentanyl and pipecuronium and in addition sevoflurane was inhaled before aortic clamping and the end-tidal concentration was rapidly increased to 1.0% and maintained at the level for 5 min in group S. Blood samples were taken from the central vein before skin incision （T1）, immediately after aortic clamping （T2 ）, at 0 and 30 min after aortic unclamping （T3-4）, and at 2, 6, 12 and 24 h after operation （T5-8 ） for determination of the concentration of serum cardiac troponin I （cTnI） and activities of creatine kinase （CK） and creatine kinase isoenzyme-MB （CK-MB）. Myocardial specimens were taken from right auricle before aortic clamping and at 10 min after aortic unclamping for electron microscopic examination. Results The concentration of serum cTnI and activities of CK and CK-MB were significantly increased at T4-8 in both groups （P 〈 0.05）. The serum cTnI concentration at T4-8 and the activities of CK and CK-MB at Ts were significantly lower in group S than in group C （ P 〈 0.05）. Different degrees of mitochondrial swelling were observed after aortic unclamping in both groups, but the changes were milder in group S than in group C. Conclusion Sevoflurane pretreatment can attenuate the myocardial injury in patients undergoing cardiac valve replacement with CPB.