Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA 94143-0648, USA.
BMC Anesthesiol. 2012 Mar 10;12:4. doi: 10.1186/1471-2253-12-4.
The effect of peripheral nerve blocks on postoperative delirium in older patients has not been studied. Peripheral nerve blocks may reduce the incidence of postoperative opioid use and its side effects such as delirium via opioid-sparing effect.
A prospective cohort study was conducted in patients who underwent total knee replacement. Baseline cognitive function was assessed using the Telephone Interview for Cognitive Status. Postoperative delirium was measured using the Confusion Assessment Method postoperatively. Incidence of postoperative delirium was compared in two postoperative management groups: femoral nerve block ± patient-controlled analgesia and patient-controlled analgesia only. In addition, pain levels (using numeric rating scales) and opioid use were compared in two groups.
85 patients were studied. The overall incidence of postoperative delirium either on postoperative day one or day two was 48.1%. Incidence of postoperative delirium in the femoral nerve block group was lower than patient controlled analgesia only group (25% vs. 61%, P = 0.002). However, there was no significant difference between the groups with respect to postoperative pain level or the amount of intravenous opioid use.
Femoral nerve block reduces the incidence of postoperative delirium. These results suggest that a larger randomized control trial is necessary to confirm these preliminary findings.
外周神经阻滞对老年患者术后谵妄的影响尚未得到研究。外周神经阻滞可能通过减少阿片类药物的使用及其副作用（如谵妄）来降低术后阿片类药物的使用和其副作用的发生率。
本前瞻性队列研究纳入了接受全膝关节置换术的患者。使用电话认知状态测试（Telephone Interview for Cognitive Status）评估基线认知功能。术后使用意识混乱评估方法（Confusion Assessment Method）评估术后谵妄。在接受股神经阻滞+患者自控镇痛（patient-controlled analgesia）和仅接受患者自控镇痛（patient-controlled analgesia only）的两组患者中比较术后谵妄的发生率。此外，比较两组患者的疼痛程度（使用数字评分量表）和阿片类药物的使用情况。
共 85 例患者入组。术后第 1 天或第 2 天发生术后谵妄的总发生率为 48.1%。股神经阻滞组的术后谵妄发生率低于仅接受患者自控镇痛组（25% vs. 61%，P=0.002）。然而，两组患者术后疼痛程度或静脉阿片类药物使用量无显著差异。
股神经阻滞可降低术后谵妄的发生率。这些结果提示需要进行更大规模的随机对照试验来证实这些初步发现。
