亚麻醉剂量氯胺酮预处理对老年患者术后认知功能的影响

目的 探讨亚麻醉剂量氯胺酮预处理对老年患者术后认知功能的影响.方法 择期行胃大部分切除术的老年患者60例,ASA分级Ⅰ-Ⅱ级,术前简易智能状态量表评分>23分,采用随机数字表法将患者随机分为2组:对照组(n=30)和氯胺酮组(n=30).全麻诱导后,氯胺酮组肌肉注射氯胺酮1.0 mg/kg,对照组给予等容量生理盐水,然后插管.术后行静脉患者自控镇痛3 d,维持良好镇痛效果.于术前1 d采用简易智能状态检查量表(MMSE)评价认知功能,并记录作为基线数据;分别于术前1 d、术后1,24,48,72 h抽取外周静脉血样3 ml,检测白细胞介素-1β(IL-1β)、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α);术后24,48,72 h采用MMSE评分评价认知功能,记录术后认知功能障碍(POCD)的发生情况.结果 两组间患者年龄、体重、性别等一般资料及手术时间、麻醉时间、MMSE基础评分和麻醉药物总量比较差异无统计学意义(P>0.05).氯胺酮组术后血浆IL-1β、IL-6和TNF-α升高程度明显低于对照组(P<0.05).与麻醉诱导前1 d相比,氯胺酮组血浆IL-1β、IL-6和TNF-α轻微升高(P>0.05),对照组则升高明显(P<0.05).对照组术后24,48,72 h POCD发生率分别为33.3%,23.3%,10.0%;氯胺酮组分别为20.0%,13.0%,6.6%;对照组在第1,2天POCD发生率明显高于氯胺酮组,差异有统计学意义(P<0.05),第3天差异无统计学意义.结论 亚麻醉剂量氯胺酮预处理对老年患者术后认知功能有保护作用,可以降低POCD发生率,推测可能与氯胺酮的抗炎性反应有关.

Effects of subanesthetic dose of ketamine preconditioning on postoperative cognitive function in the elderly patients

Objective To investigate the effect of the subanesthetic dose of ketamine preconditioning on the postoperative cognitive function in elderly patients.Methods Sixty ASA Ⅰ or Ⅱelderly patients,scheduled for subtotal gastrectomy,35 males and 25 females,with preoperative mini-mental state examination(MMSE) scores above 23,were randomized into 2 groups:control group(n=30)and ketamine group(n=30).After induction of general anesthesia,the patients received an intramuscular injection of 1.0 mg/kg ketamine in ketamine group and the same volume of physiological saline in control group,and then intubated.After surgery,all patients had access to PCIA for 3 d to maintain the good postoperative analgesia.Mini-mental state examination(MMSE) was used to evaluate the cognitive function 1d before operation and at 24,48,72 h after operation,and recorded as the baseline.Peripheral venous blood samples were taken to detect the levels of IL-1β,IL-6,and TNF-α one day before surgery,and 1,24,48,72 h after surgery.Results There was no significant difference between two groups with respect to age,weight,gender,the duration of the operation,the duration of the anaesthesia,MMSE baseline score and the total amount of anaesthetic(P>0.05).Compared with control group,the serum levels of IL-1β,IL-6 and TNF-α were significantly increased after operation in ketamine group(P<0.05).After operation,serum concentrations of IL-1β,IL-6 and TNF-a were increased significantly in control group(P<0.05),but not in ketamine group(P>0.05).The incidences of postoperative cognitive dysfunction(POCD) were 33.3%,23.3%,10.0% in control group at 24,48,72 h after surgery,respectively,and 20.0%,13.0%,6.6% in ketamine group.The incidence of POCD at 1,2 d after surgery in control group were significantly higher than those in ketamine group(P<0.05),but no significant difference was found at 3 d after surgery between two groups.Conclusion The results suggest that subanesthetic dose of ketamine preconditioning has protective effect on postoperative cognitive dysfunction(POCD) in elderly patients,and that it can decrease the incidence of POCD,which may be related with the anti-inflammatory effect of ketamine.