全身麻醉术后对中老年病人认知功能的影响

The influence of general anesthesia on postoperative cognitive function

目的 研究全身麻醉对非心脏外科术后认知功能的影响。方法 随机选择40例无神经、精神系统疾病史或服用相应药物的择期非心脏外科手术病人（ASAI-Ⅱ）,其中20例施行全身麻醉,20例施行全身麻醉复合硬膜外阻滞,分别就7项认知功能于术前、术后3d和7d进行测定评分。7项测试项目中至少2项,其中单项测试值低于基础值20％以上者即确定为认知功能损害。结果 40例病人术后3d和7d认知功能紊乱发生率分别为65.2％和40％。术后早期认知功能紊乱全麻复合硬膜外阻滞与单纯全麻组间无显著性差异。年龄与术后认知功能测试项目中的视觉再生（γ=-0.49）和钉板试验（γ= 0.49）有相关关系（P<0.05）。结论 非心脏外科手术后病人特别是高龄病人早期存在认知功能紊乱,应当引起临床医生的足够重视。

Objective To determine the influence of general anesthesia on postoperative cognitive function in patients undergoing noncardiac surgery. Methods Forty ASA Ⅰ -Ⅱ patients aged 50-70 years undergoing elective noncardiac surgery under general anesthesia ( n = 20) or general anesthesia combined with epidural block (n =20) were studied.Patients with psychiatrical or neurological disorders or taking hyponotics regularly were excluded.General anesthesia was induced with propofol 1.5-2.5mg/kg and fentanyl 2μg/kg.Tracheal or bronchial intubation was facilitated with vecuronium 0.6mg/kg.The patients were then mechanically ventilated and PETCO2 was maintained at 30-40mm Hg. Anesthesia was maintained with 1.0%-2.0% isoflurane and intermittent iv boluses of vecuronium. Epidural catheter was inserted at T8.9 and a mixture of 0.33% poutocaine and 2%lidocaine was infused through catheter at a rate of 4-6ml/h by using Graseby 3500 infusion pump.Radial artery was cannulated for intra-arterial pressure monitoring. ECG, PETCO2 and end-tidal-isoflurane concentration were monitored during operation. Whenever BP was < 90/60mm Hg or decreased by 30 % of the baseline value, ephedrine 6mg was given iv at a time. The patients were asked to perform at least two of the following seven cognitive tests before operation and on the 3rd and 7th postoperative day: (1) response of the patient in doing addition, (2) visual reproduction test, (3) verbal tearing ability, (4) the digital span test, (5) digit symbol test, (6) the trial marking test-A and (7) pegboard test. If the patient scored less than 20% of the baseline value in both tests, the patients was considered to have cognitive dysfuntion. Results The percentage of the patients who developed postoperative cognitive dysfunction (POCD) was 65.2% on the 3rd postoperative day and 40% on the 7th day after operation. There was no significant difference in the incidence of POCD between the two anesthesia groups (general vs general) .There was no significant correlation between the incidence of POCD and patients height, body weight, duration of operation or the level of education. Only age was significantly correlated with visual reproduction test and pegboard test. Conclusions Short-term postoperative cognitive dysfunction after non-cardiac surgery is a frequent complication and may result from many factors. More attention should be to POCD either short term or persistent.