摘要目的 探讨老年病人全麻术后颅内兴奋性氨基酸(EAA)水平的变化与术后认知功能障碍(POCD)发生的关系.方法 40例择期老年病人行全麻手术,年龄65～79岁,ASA Ⅰ～Ⅲ级.于麻醉前、术毕、术后24、48和72h时取颈内静脉球部血样,采用反相高效液相色谱荧光法(RP-HPLC)检测血浆EAA浓度.所有患者均实施有效的术后镇痛,采用简易智力状态检查法(MMSE)分别评估麻醉前、术后3d认知功能.结果 术后3d期间,11例病人发生POCD(28%).与麻醉前比较,术后24、48h POCD病人血浆谷氨酸(Glu)、天冬氨酸(Asp)、甘氨酸(Gly)浓度升高(P<0.05或0.01),术后72h恢复.与非POCD病人比较,术后24、48h POCD病人血浆Glu、Asp、Gly浓度升高(P<0.05).POCD病人Glu和Asp浓度与MMSE评分呈显著负相关(Glu:r=-0.86,P<0.01;Asp:r=-0.99,P<0.01).结论 老年病人全麻术后颅内EAA水平的升高可能参与了POCD发生的病理生理过程.

abstractsObjective To investigate the relationship between the changes in intracranial excitatory amino acid(EAA) levels and the incidence of postoperative cognitive dysfunction (POCD) in eldedy patients after general anesthesia. Methods Forty ASA Ⅰ-Ⅲ patients of both sexes aged 65-79 yr weighing 48-76 kg undergoing elective non-cardiac surgery under general anesthesia were studied.Anesthesia was induced with midazolam,fentanyl,etomidate and succinylcholine and maintained with continuous iv infusion of propofol,remifentanil,isoflurane inhalation and intermittent iv boluses of vecuronium.The right internal jugular vein was cannulated with a catheter which was advanced cephalad until jugular bulb.The jugular bulb venous blood samples were taken before (T0,baseline),at the end of (T1) and at 24,48 and 72h(T2-4) after operation for measurement of plasma concentrations of glutamate (Glu),aspartate (Asp) and glycine (Gly) by RP-HPLC.The cognitive function was evaluated by mini-mental state examination (MMSE) at T0 and T4.Results Eleven of the 40 patients developed POCD (28%).The plasma Gh,Asp and Gly concentrations were significantly increased after operation as compared with the baseline values in POCD patients and were significantly higher than in non-POCD patients.The plasma concentrations of Glu and Asp were negatively correlated with MMSE score(Glu:r=-0.86.P<0.01;Asp:r=-0.99,P<0.01).Conclusion Elderly patients may develop POCD after operation performed under general anesthesia through increase in intracranial EAA levels.