右美托咪啶对老年人术后认知功能的影响

Effects of Dexmedetomidine on Postoperative Cognitive Function in Elderly Patient

目的:探讨右美托咪啶对老年人术后认知功能的影响及可能作用机制。方法:将择期手术治疗的腰椎骨折和髋关节置换术46例患者随机分为对照组(I组)和右美托咪啶组(II组),II组麻醉诱导前静脉输注右美托咪啶,负荷剂量0.8 ug/kg,输注时间10～15 min,以0.5 mg.kg-1.h-1的速率持续至术毕,I组给予等容量的生理盐水。于给药前(T1)、手术开始后1 h(T2)和手术结束后(T3)检测血浆皮质醇浓度,分别于术前1 d、术后1 d、术后3 d、术后7 d评估病人认知功能状态。结果:与I组比较,II组术后认知功能障碍发生率明显降低(P<0.05),皮质醇浓度在麻醉诱导后(T2)明显降低(P<0.05)。结论:右美托咪啶围术期给药,可预防老年人认知功能障碍发生,其可能机制与降低皮质醇浓度有关。

Objective To investigate the effects of dexmedetomidine on postoperative cognitive function and possible mechanism in elderly patients. Methods Forty-six ASA I or Ⅱ elderly patients were randomly divid- ed into 2 groups：control group（group I）and dexmedetomidine group（group Ⅱ）.Dexmedetomidine was injected i.v . over 10-15 rain before ane- sthesia induction,and then was infused at a lower rate （group Ⅱ） until the end of op- eration.Group I received equal volume of normal saline. The plasma eortisol concentrations were detected at 3 time points：before anesthesia ,at lh after the beginning of operation and at the end of operation.Postoperative cog- nitive function was evaluated at 1 day before operation, ld,3d and 7d after operation with Mini-mental state ex- amination,and the postoperative cognitive dysfunction was recorded. Results The incidence of postoperative cognitive dysfunction was significantly lower in group Ⅱthan in group I.The plasma cortisol concentration in groupⅡ after intubation was inhibited stronger than in group I（P〈0.05）. Conclusion Dexmedetomidine can prevent postoperative cognitive dysfunction in elderly patients by perioperative treatment, and the possible mech- anism is related to reduction of cortisol level.