改良极化液对体外循环二尖瓣置换患者心脏功能的作用及其机制

目的探讨改良极化液对体外循环（ECC）二尖瓣置换患者心脏功能的作用及其机制。方法将40例心脏二尖瓣置换患者随机分为对照组（19例）和改良极化（GIK）液治疗组（21例）。GIK组于麻醉诱导前经中心静脉给予改良GIK液500ml，对照组给予等量的平衡盐。分别于围术期不同时间点测定心脏指数（cI）、体循环阻力（SVR）、肺循环阻力（PVR），左心室射血分数（LVEF）、血浆葡萄糖、胰岛素、糖皮质激素、肾上腺素、乳酸水平，并计算胰岛素抵抗指数（HOMA-IRI）。结果GIK组患者术后24h、48h的CI和LVEF显著高于对照组，SVR、PVR显著低于对照组；ECC期间血浆葡萄糖、胰岛索水平高于对照组，术后低于对照组；术后12h、24h的HOMA-IRI低于对照组；围术期的乳酸水平低于对照组；糖皮质激素水平在ECC结束及术后24h低于对照组；肾上腺素水平ECC结束及术后均高于对照组；术后正性肌力药物用量显著低于对照组。结论围ECC期给予改良GIK液治疗，改善患者术后早期心脏功能和血流动力学状态，其机制可能与降低应激水平，改善机体代谢，维持内环境稳定有关。

Effect of modified glucose-insulin-potassium solution on cardiac function in patients undergoing mitral valve replacement with extracorporeal circulation

Objective To investigate the effect of modified glucose-insulin-potassium(GIK) solution on cardiac function and its mechanism in patients undergoing mitral valve replacement(MVR) with extracorporeal circulation(ECC). Methods Forty consecutive patients undergoing MVR were randomized into control group(n=19) and GIK group(n=21).The GIK group received GIK solution 500 ml(glucose 20%,insulin 33 IU,10% potassium chloride 30 ml) via central venous catheter at 60 ml per hour before induction of anesthesia and ended about six hours after aortic cross clamp(AXC) removal.The control group received equivalent 0.9% Sodium chloride in the same fashion.Peri-operative hemodynamic data and left ventricular ejection fraction(LVEF),serum concentrations of glucose,insulin,glucocorticoids,epinephrine and lactic acid were measured,and the insulin resistance index(HOMA-IRI) was calculated at different time points. Results The cardiac index(CI) at postoperative 24 and 48 hours of GIK group increased significantly compared with control group;the LVEF of GIK group was higher than that of control group.The systemic vascular resistance(SVR) and pulmonary circulation resistance(PVR) at postoperative 24 and 48 hours in GIK group decreased significantly compared with control group.The levels of blood glucose and insulin of GIK group were higher during the period of ECC but were lower postoperatively than that of control group.The HOMA-IRI of GIK group was lower than that of control group at postoperative 12 and 24 hours.The level of blood glucocorticoid of GIK group was lower and the level of blood epinephrine of GIK group was higher than that of control group at the end of ECC.Meanwhile,the peri-operative level of serum lactic acid was decreased in GIK group compared with control group. Conclusion GIK therapy during the peri-ECC period can significantly improve the cardiac function and hemodynamic status of MVR patients,and the mechanism may be related to its ability of stress reduction and metabolism stabilization.