氯胺酮超前镇痛对术后自控镇痛效果和应激反应的影响

目的：观察氯胺酮超前镇痛对下腹部手术患者围术期应激反应及自控镇痛效果的影响。方法：45例子宫肌瘤患者均于硬膜外麻醉行全子宫切除术，随机分为3组，即Ⅰ组：对照组，术前不施行超前镇痛；Ⅱ组：切皮前30 min静脉注入氯胺酮0.2 mg•kg^-1；Ⅲ组：切皮前30 min将氯胺酮30 mg加入实验剂量(2%利多卡因4或5 mL)中注入硬膜外腔。3组术后均连接Graseby9300镇痛泵行患者自控硬腺外镇痛(PCEA)，镇痛药物为0.2%罗哌卡因加50 mg•L^-1吗啡。分别于术前、术后第1、2天晨抽取静脉血，采用改良荧光法测定血浆肾上腺素（E）和去甲肾上腺素（NE），用放射免疫法检测血清皮质醇水平，并于术后不同时间点观察视觉模拟(VAS)评分、镇痛泵首次触发时间、吗啡消耗量、有效触发次数以及术后恶心、呕吐和皮肤瘙痒的发生率。 结果：从术后4 h至48 h 3组患者的VAS评分均升高，Ⅰ、Ⅱ、Ⅲ组之间差异无显著性，Ⅱ、Ⅲ两组PCEA泵首次触发时间明显延长，镇痛期内按压次数、吗啡总消耗量、不良反应发生率明显减少。Ⅰ组术后E及NE水平均高于术前，Ⅱ、Ⅲ组术后第1天E、NE水平均高于术前，第2天E、NE水平与术前无差别，与Ⅰ组术后第2天相比差异有显著性（P<0.05）。 结论：小剂量氯胺酮经硬膜外腔或静脉途径行超前镇痛能减轻下腹部手术术后儿茶酚胺和皮质醇的增高反应，提高患者自控镇痛效果，减轻阿片类药物的用量和不良反应。

Pre-emptive analgesia effects of ketamine on postoperative pain management and stress responses

Objective To study the pre-emptive analgesia effects of ketamine on postoperative pain management and stress responses. Methods Forty-five patients with hysteromyoma undergone hysteromyomectomy were randomly assigned to three groups (n=15,each group): group Ⅰ, control group without pre-emptive analgesia; group Ⅱ, the patients were administrated with 0.2 mg·kg -1 ketamine intravenously 30 min before operation; group Ⅲ, 30 mg ketamine was administrated into epidural analgesia 30 min before operation. All patients received postoperative analgesia with patient controlled epidural analgesia(PCEA). The VAS and first PCEA trigger time (min), morphine consumption (mg) and the number of PCEA successful triggers, analgesic-related adverse effects were observed. The changes of epinephrine (E), norepinephrine (NE) in plasma were detected by improved fluorescence method, and cortisol level in serum were also measured by radioimmunoassay. Results The VAS were significantly different between groupⅠ,Ⅱand Ⅲ. The first PCEA trigger times of groupⅡ and Ⅲ were longer than that of groupⅠ. The number of PCEA successful triggers and morphine consumptions two days after operation in group Ⅱ and Ⅲ were significantly less than those in groupⅠ; the levels of E and NE in plasma were increased in group Ⅱ and Ⅲ one day after operation and in group Ⅰ during 48 hours after operation, but the degree in group Ⅱ and Ⅲ was lower than that in groupⅠtwo days after operation. Conclusion The pre-emptive analgesia of ketamine can decrease morphine consumption, stress response time and analgesic-related adverse effects.