亚麻醉剂量氯胺酮与右美托咪定对老年骨科全麻患者早期术后认知功能障碍的影响

目的：观察亚麻醉剂量氯胺酮与右美托咪定对老年骨科全麻患者早期术后认知功
能障碍（POCD）的影响，并阐明其相关机制。方法：选择年龄60岁以上择期行骨科手术的全麻
患者120例，随机分为氯胺酮组、右美托咪定组、氯胺酮+右美托咪定组及生理盐水对照组，
每组30例。所有患者均采用全凭静脉麻醉。麻醉前，氯胺酮组患者给予0.5 mg/kg
氯胺酮静脉注射；右美托咪定组患者首先经静脉输注右美托咪定1 μg/kg，随后
以0.5 μg/kg/h的速度输注至术毕前30 min；氯胺酮+右美托咪定组患者同时静脉输
注氯胺酮和右美托咪定；对照组患者静脉输注生理盐水。分别于术前1 d及术后1、7 d使用简易智能精神
状态检查量表（MMSE）进行评分，记录POCD发病率；并分别于麻醉前、手术结束、术后24 h
抽取静脉血，检测血清白细胞介素6（IL-6）水平。结果：与对照组比较，右美托咪定组患
者清醒睁眼至拔管时间(T2)明显延长(P<0.05)。各组患者术后1和7 d POCD发病率，对照组为26.7%、13.3%，氯胺酮组为6.7%、0%，右美托咪定组为20.0%、10.0%，氯胺酮+右美托咪定组为13.3%、3.3%；与对照组比较，氯胺酮组患者术后1和7 d POCD发病
率明显降低（P<0.05），右美托咪定组及氯胺酮+右美托咪定组术后1和7 d POCD发病率差异均无统计学意义（P>0.05）。各组患者血清IL-6水平比较差异无统计学意义（P>0.05）。结论：术中单独应用亚麻醉剂量氯胺酮可以减少骨科全麻患者术后早期POCD的发病率，右美托咪定或氯胺酮与右美托咪定复合应用不能降低术后早期POCD的发病率，且POCD的发生与炎症反应无关。

Influence of sub-anesthetic dose of ketamine and dexmedetomidine on early postoperative cognitive function in elderly orthopedic patients under total intravenous anesthesia

Objective To observe the influence of the sub-anesthetic doses of ketamine and dexmedetomidine on early postoperative cognitive dysfunction(POCD) underwent orthopedic surgery in elderly patients,and to clarify its related mechanism.Methods 120 patients aged 60 years underwent elective orthopedic surgery were randomly divided into ketamine group,dexmedetomidine group,ketamine+dexmedetomidine group and control group,30 cases in each group.All patients received total intravenous anesthesia.Before anesthesia,the patients in ketamine group received 0.5 mg·kg-1 ketamine intravenous injection.The patients in dexmedetomidine group received infusion of dexmedetomidine 1 μg·kg-1 at first,followed by 0.5 μg·kg-1·h-1 infusion until 30 min before the end of operation.The patients in ketamine+dexmedetomidine group received intravenous infusion of ketamine and dextromedetomidine.The patients in control group received intravenous infusion of saline.The Mini Mental State Examination(MMSE) was used to assess cognitive function 1 d before operation and 1,7 d after operation.The incidence of POCD was recorded.Blood samples were taken before anesthesia induction,at the end of operation and 24 h after operation for determination of IL-6.Results Compared with control group,the time from consciousness to extubation of the patients in dextromedetomidine group was singnificantly prolonged(P<0.05).The incidence of POCD were 26.7% and 13.3% in control group at 1,7 d after operation,6.7% and 0 in ketamine group,20.0% and 10.0% in dexmedetomidine group,13.3% and 3.3% in ketamine+dexmedetomidine group.Compared with control group,the incidence of POCD in ketamine group at 1,7 d after operation was significantly decreased(P<0.05),the incidence of POCD in dexmedetomidine group and ketamine + dexmedetomidine group at 1,7 d after operation had no significant differences(P> 0.05).The serum IL-6 levels had no significant difference between various groups(P<0.05).Conclusion The application of sub-anesthetic dose of ketamine can reduce the incidence of early POCD in orthopedic surgery.Dexmedetomidine alone or combined with ketamine can not reduce the incidence of early POCD in orthopedic surgery.The occurrence of POCD has nothing to do with inflammatory reaction.