小剂量氯胺酮对体外循环促炎细胞因子反应及心肌损伤的影响

目的 探讨小剂量氯胺酮对体外循环（CPB）诱发的促炎细胞因子反应及心肌损伤的影响。方法 20例择期瓣膜替换术病人，随机分成氯胺酮组（n＝10）和对照组（n＝10）。氯胺酮组于麻醉诱导和转流开始时按1mg.kg^-1静注氯胺酮，对照组则采用等量生理盐水注射。分别于术前（T1）、CPB60min（T2）、CPB结束后2h（T3)、4h(T4)及24h（T5）各时间点测定动脉血中下列各项指标；肿瘤坏死因子－α（TNF－α）、白细胞介素－6（IL－6）、白细胞介素－8（IL－8）、血浆过氧化脂质（LPO）、心肌肌酸酶同工酶（CK－MB）。结果 与术前（T1）比较，两组TNF－α、IL－6、IL－8、LPO、CK－MB均明显升高（P＜0．05或0．01）；但氯胺酮组T2－T5TNF－α、IL－6、IL－8浓度、T3LPO浓度和T3、T4、CK－MB活性均显著低于对照组（P＜0．05）。结论 小剂量氯胺酮能有效抑制CPB诱发的促炎细胞因子反应和心肌损伤。

Effects of low-dose ketamine on cardiopulmonary bypass-induced proinflammatory cytokine response and myocardial injury

Objective To investigate the effects of low-dose ketamine on cardiopulmonary bypassinduced proinflammatory cytokine response and myocardial injury. Methods Twenty adult patients undergoing cardiac valve replacement were randomly divided into control and ketamine group of ten patients each. All patients were premedicated with intramuscular pethidine 1.0 mg@ kg-1 and scopolamine 0. 006 mg @ kg-1 . Anesthesia was induced with midazolam 0.15mg@ kg-1, fentanyl 10μg@ kg-1 and vecuronium 0.1 mg@ kg-1 administered intravenously. After tracheal intubation the patients were mechanically ventilated with pure oxygen. PET CO2 was maintained within normal range. Anesthesia was maintained with intermittent intravenous bolus of fentanyl and vecuronium. The total dose of fentanyl amounted to 40 μg@kg-1. MAP, CVP, HR, PETCO2, SpO2, nasal and rectal temperature were monitored continuously. In the ketamine group, ketamine lmg@ kg-1 was given intravenously twice, first before induction of anesthesia and then before the initiation of hypothermic CPB. Blood samples were taken from radical artery before operation(T1) and 2h, 4h, and 24h after weaning from CPB(T3, T4, T5) for determination of plasma levels of tumor necrosis factor (TNF)α, interleukin (IL)-6, and IL-8, lipid peroxide(LPO) and creatine kinase isoenzyme(CK-MB) activity .Results The age, body weight, aortic cross-clamp time, CPB time,duration of operation, and changes in hemodynamics were comparable between the two groups. In both groups TNF-α, IL-6, IL-8, LPO concentrations and CK-MB activity increased significantly from T2-T5 as compared with the baseline values (P<0.05 or 0.01), but TNF-α, IL-6 and IL-8 levels at T2-T5, LOP level at T3 and CK-MB activity at T3 and T4 were significantly lower in ketamine group than those in control group (P<0.05).Conclusions Low-dose ketamine is effective in reducing CPB-induced proinflammatory cytokine response and myocardial injury.[Key Words] Ketamine; Cardiopulmonary bypass; Myocardial reperfusion injury