氯胺酮具有诱导迅速,镇痛强,作用时间短,毒性低,可以重复用药等特点,已广泛用于小儿麻醉。但对于长时间的小儿手术,单一用药很难满足手术要求,术中需反复追加药量,致使血流动力学波动明显。为了减轻氯胺酮的不良反应,提高小儿麻醉的成功率及安全性,我院从2004年12月-2005年12月 Ketamine has the characteristics of rapid induction, strong analgesia, short acting time, low toxicity and repeated administration, and has been widely used in pediatric anesthesia. But for a long time pediatric surgery, a single medication is difficult to meet the surgical requirements, intraoperative need to repeatedly add the dose, resulting in significant fluctuations in hemodynamics. In order to reduce the adverse reaction of ketamine and improve the success rate and safety of pediatric anesthesia, our hospital from December 2004 -2005 December