小剂量吗啡关节内注射用于膝关节镜术后镇痛的临床观察及机制探究

Study on the effect of low-dose intra-articular morphine after knee arthroscopy and its mechanism in molecular level

目的 观察和对比小剂量吗啡关节内注射用于膝关节镜术后的镇痛效果和慢性炎症时膝关节滑膜组织μ阿片受体的表达。方法 采用随机分组,双盲研究。腰麻下行膝关节镜手术病人100例,随机分为吗啡组和对照组,每组50例。吗啡组手术后在关节内注射盐酸吗啡1mg,对照组注射等体积的生理盐水,给药后8和24h在病人双足站立、膝关节伸展状态下进行视觉模拟评分(VAS),观察吗啡用于膝关节手术后的镇痛效果。膝关节内阿片受体免疫组化研究以成年人膝关节滑膜组织为研究对象,分为炎性组和对照组,每组20例。炎性组取自诊断为慢性膝关节炎需做全膝置换手术的病人,对照组取自健康成年人膝关节滑膜组织。采用免疫组化的方法测定μ阿片受体的表达情况。结果 给药后8和24h,吗啡组VAS评分为1.7±1.0和1.4±1.0,而对照组为3.7±1.5和2.4±1.3,吗啡组均显著低于相应的对照组,两组有显著差异。免疫组化结果显示,炎性组膝关节滑膜组织μ阿片受体光密度值、阳性细胞百分率较对照组显著增高(P<0.05)。结论 小剂量吗啡关节内注射可以有效缓解膝关节镜手术后的疼痛,其机制可能与膝关节组织阿片受体上调有关。

Objective To evaluate the analgesic effects of low-dose intra-articular morphine after knee arthroscopy and compare the expression of μ opioid receptor in the knee joint synovium tissue when chronic inflammation. Methods In the double-blind study, 100 patients were randomized to receive either low-dose morphine 1mg(morphine group,n = 50)or the same volume of normal saline solution(control group, n = 50) intra-ardcularly at the end of arthroscopic knee surgery. Analgesic efficacy was evaluated by visual analogue scale(VAS) 8 and 24 hours after administration of morphine or placebo. The synovium tissues of the knee joint in adults were used to compare the expression of μ-opioid receptors when chronic inflammation. The chronic inflammation patients who received total knee replacement were allocated to the inflammation group(n = 20) ,and the healthy adults were allocated to the control group(n=20). Immunohistochemical technique was used to measure the contents of μ-opioid receptor in the knee joint of two groups. Results 8 hours and 24hours after administration, the scores of VAS were 1. 7 ± 1. 1 and 1. 4 ± 1. 0 in morphine group, respectively, which were significantly less than those 3. 7±1. 5 and 2. 4±1. 3 in control group, respectively (P<0. 05). Immunohistochemical results revealed that the optical density (OD) of immunoreaction of μ-opioid receptor in the knee synovium tissue in the chronic inflammation group were significantly more than that in control group. Conclusion Low-dose intra-articular morphine can effectively relieve the pain after arthroscopic knee surgery, which related to the up-regulation of μ-opioid receptor in knee synovium tissue.