Department of Anesthesiology Shanghai General Hospital Affiliated to Shanghai Jiaotong University Shanghai China.
Brain Behav. 2018 Jan 30;8(2):e00910. doi: 10.1002/brb3.910. eCollection 2018 Feb.
Clinical observation, as well as randomized controlled trials, indicated an increasing rate of postoperative cognitive dysfunction (POCD) with increasing depth of general anesthesia. However, the findings are subject to bias due to varying degree of analgesia. In this trial, we compared the rate of POCD between patients receiving light versus high anesthesia while holding analgesia comparable using nerve block.
Elderly patients (≧60 years) receiving elective total knee replacement were randomized to receive the surgery under general anesthesia at BIS 40-50 (LOBIS group) or BIS 55-65 (HIBIS group). The femoral nerve and the sciatic nerve were blocked under ultrasonic guidance in all patients before induction. Cognitive performance was assessed with Montreal cognitive assessment (MoCA) at the baseline and 1d, 3d, and 7d after the surgery. POCD was defined by Z score of >1.96 using cross-reference. The extubation time and recovery time were also compared.
A total of 66 patients were randomized; 60 ( = 30 per group) completed trial as the protocol specified. POCD occurred in six patients (20%) in the LOBIS group vs. in one patient (3.3%) in the HIBIS group (Figure 3, = .04). In all seven cases, the diagnosis of POCD was based on MoCA assessment on 1d after the surgery. Assessment in 3d and 7d after surgery did not reveal POCD in any case. Extubation time was longer in the LOBIS group (12.16 ± 2.58 vs. 5.77 ± 3.01 min in the HIBIS group (.001)). The time of comeback of directional ability was 13.47 ± 3.14 and 6.17 ± 3.23 min in the LOBIS and HIBIS groups, respectively (.001).
In elderly patients receiving a total knee replacement, lighter anesthesia could reduce the rate of POCD with complete analgesia during surgery.
临床观察和随机对照试验表明，全身麻醉深度增加与术后认知功能障碍（POCD）的发生率增加有关。然而，由于镇痛程度不同，这些发现可能存在偏差。在本试验中，我们比较了在保持镇痛效果相当的情况下，接受浅麻醉和深麻醉的患者之间 POCD 的发生率，方法是使用神经阻滞。
择期行全膝关节置换术的老年患者（≧60 岁）随机分为在 BIS 40-50 下接受全身麻醉（LOBIS 组）或 BIS 55-65 下接受全身麻醉（HIBIS 组）。所有患者在诱导前均在超声引导下进行股神经和坐骨神经阻滞。在手术前、手术后 1d、3d 和 7d 使用蒙特利尔认知评估（MoCA）评估认知功能。使用交叉参考定义 POCD 为 Z 评分>1.96。还比较了拔管时间和恢复时间。
共有 66 例患者被随机分配；60 例（每组 30 例）按方案完成试验。在 LOBIS 组中有 6 例（20%）发生 POCD，而在 HIBIS 组中有 1 例（3.3%）发生 POCD（图 3，=0.04）。在所有 7 例中，POCD 的诊断均基于手术后 1d 的 MoCA 评估。在手术后 3d 和 7d 的评估中，在任何病例中均未发现 POCD。LOBIS 组的拔管时间更长（12.16±2.58 与 HIBIS 组的 5.77±3.01 min，<.001）。定向能力恢复的时间分别为 LOBIS 组的 13.47±3.14 min 和 HIBIS 组的 6.17±3.23 min，（<.001）。
在接受全膝关节置换术的老年患者中，浅全身麻醉可降低手术期间完全镇痛的 POCD 发生率。
