关节腔内注射吗啡复合布比卡因、玻璃酸钠对膝关节镜术后疼痛的影响

目的观察膝关节镜术后关节腔内注射不同药物镇痛效果的差异。方法40例在腰麻下行膝关节镜手术病人随机分为两组(n=20),术后向关节腔内注入不同的药物。BM组:布比卡因75 mg加吗啡2 mg;HM组:玻璃酸钠30mg加吗啡2 mg。记录术后8、12、24、48 h患者屈膝关节90°VAS评分及不良反应。结果术后第8、12、24、48 h患者屈膝关节90°VAS评分HM组显著低于BM组。差异有统计学意义(P<0.05),两组病人仅BM组有1例出现皮肤瘙痒,余无一例出现恶心、呕吐、皮肤瘙痒和尿潴留等不良反应。结论关节腔内注射玻璃酸钠复合吗啡可有效缓解膝关节镜术后疼痛,其镇痛效果优于布比卡因复合吗啡。     

关节腔内给予右美托咪定对膝关节镜术后镇痛的影响

目的 本研究评价关节腔内给予右美托咪定对膝关节镜术后镇痛的影响.方法 拟行膝关节镜手术患者60例,随机均分为三组:关节组关节腔内给予右美托咪定0.7 μg/kg(用生理盐水配置成15 ml),静脉给予生理盐水15 ml;静脉组静脉内给予右美托咪定0.7 μg/kg(用生理盐水配置成15ml),关节腔内给予生理盐水15 ml;对照组静脉和关节腔内给予生理盐水各15 ml.记录患者术后静息时和运动时VAS评分和术后2h改良Ramsay镇静评分,以及术毕至首次需要镇痛药时间和术后24 h内曲马多用量.结果 关节组术后1～6h.静脉组术后1h静息时和运动时VAS评分明显低于对照组(P＜0.05).首次使用镇痛药时间.关节组(198.0±50.5)min明显长于静脉组(97.0±39.5)min和对照组(62.0±28.1)min(P＜0.01).使用曲马多剂量关节组(82.0±36.5)mg明显低于静脉组(119.2±44.1)mg和对照组(163.0±52.5)mg(P＜0.01),静脉组又明显低于对照组(P＜0.05).术后2h改良Ramsay镇静评分静脉组明显高于关节组和对照组(P＜0.05).结论 关节腔内给予右美托咪定可提供膝关节镜术后的有效镇痛,延长术后首次使用镇痛药的时间和减少术后镇痛药的使用.     

关节腔内注射酮咯酸氨丁三醇用于老年患者膝关节镜术后镇痛

目的 观察关节腔内注射酮咯酸氨丁三醇或吗啡复合罗哌卡因对老年患者膝关节镜术后的镇痛效果.方法 48例腰一硬联合阻滞下行膝关节镜手术的老年患者,随机均分为关节腔内注射吗啡复合罗哌卡因组(RM组)、酮咯酸氨丁三醇复合罗哌卡因组(RK组)和生理盐水对照组(C组),记录术后2、4、8、12、24和48 h患者屈膝关节90°状态下的VAS评分、镇痛满意度及术后8 h内按需注射曲马多用量.结果 术后2、4、8、12、24和48 h患者屈膝90°VAS评分RM、RK组均显著低于C组(P<0.01);术后镇痛满意度RM、RK组较C组高,而RK组高于RM组(P<0.05);RM、RK组术后8 h曲马多平均使用量较C组明显减少(P<0.05).结论 关节腔内注射酮咯酸氨丁三醇复合罗哌卡因可有效缓解老年患者膝关节镜术后疼痛,患者满意程度优于吗啡复合罗哌卡因.     

硬膜外腔注射氢吗啡酮在剖宫产术后镇痛的临床观察

目的 观察硬膜外腔注射不同剂量盐酸氢吗啡酮对剖宫产术后镇痛的效果和安全性.方法 选择单胎足月于硬膜外麻醉下行剖宫产手术的初产妇60例,按随机数字表法分为A组、B组、C组,每组20例.3组分别于术毕前10 min经硬膜外腔注射5 ml生理盐水稀释的盐酸氢吗啡酮0.1、0.2、0.3 mg.记录术后3、6、12、24 h的疼痛VAS评分,24 h镇痛药物追加的例数及术后副作用发生的情况.结果 术后6、12、24 h的VAS评分C组低于A、B两组,B组低于A组(P＜0.05);镇痛药追加例数C组(2例)少于A组(8例)(P＜0.05);副作用组间比较差异无统计学意义(P＞0.05).结论 硬膜外腔内注射不同剂量的盐酸氢吗啡酮用于剖宫产术后早期可获得良好的镇痛效果,0.3 mg的盐酸氢吗啡酮效果更佳.     

地塞米松和吗啡关节内注射用于膝关节镜术后镇痛

目的观察和比较地塞米松和小剂量吗啡配伍关节内注射用于膝关节镜手术后的镇痛效果。方法选择ASAⅠ～Ⅱ级择期腰麻下行单侧膝关节镜手术的病人90例,随机分为三组,每组30例。Ⅰ组手术后在关节内注射地塞米松5 mg＋盐酸吗啡1 mg;Ⅱ组手术后在关节内注射盐酸吗啡1 mg;Ⅲ组手术后在关节内注射生理盐水5 mL。给药后8、24、36、48 h在病人双足站立、膝关节伸展状态下进行视觉模拟评分（visual analogue scales,VAS）,观察三组膝关节手术后的镇痛效果以及不良反应,如呼吸抑制、恶心呕吐、尿潴留及搔痒等症状的发生率。结果给药后8、24、36、48 h,Ⅰ组VAS评分均显著低于Ⅱ组（P〈0.05或P〈0.01）和Ⅲ组（P〈0.01）;Ⅱ组给药后8、24 h VAS评分显著低于Ⅲ组（P〈0.05）,36、48 h VAS评分和Ⅲ组相比无显著性差异（P〉0.05）;Ⅱ组36、48 h VAS评分和8、24 h相比显著升高（P〈0.05）。三组患者术后均未发生呼吸抑制、恶心呕吐、尿潴留及搔痒等不良反应。结论地塞米松和小剂量吗啡关节内注射或单纯小剂量吗啡关节内注射均可有效缓解膝关节镜手术后的疼痛,而前者效果更好,更持久。     

膝关节腔内复合镇痛的疗效观察

目的观察膝关节镜术后关节腔内注射复合麻醉剂的临床效果。方法膝关节镜手术120例,男60例,女60例,随机分为注射组和对照组各60例,注射组手术结束前给予关节腔内复合麻醉剂12 ml,其中含0.75%罗哌卡因10 ml+舒芬太尼10 ug+玻璃酸钠注射液20 mg。对照组未注射任何药品。观察比较两组患者术后不同时点膝关节疼痛评分、术后追加止痛剂及术后并发症的发生情况。结果注射组可以明显缓解患者术后疼痛的发生。尤其在术后4、6、12、24 h,4个时点VAS评分明显小于对照组(P<0.05),仅术后48h时点两组VAS评分无统计学差异(P>0.05)。术后患者血压、心率平稳、意识清醒、伤口愈合良好、无感染发生、无皮肤瘙痒及术后软骨损害等并发症,两组比较无统计学意义。结论膝关节镜术后关节腔内注射复合麻醉剂镇痛效果好、并发症少及操作简单、安全等优点。     

地佐辛关节腔内注射对膝关节镜术后镇痛效果研究

目的探讨地佐辛关节腔内注射对膝关节镜术后镇痛效果及安全性的临床研究。方法选择2018年1月至2019年12月绍兴市中心医院接受膝关节镜手术的80例患者进行研究,通过随机数表法分为对照组和观察组,每组40例,对照组术后给予氢吗啡酮关节腔内注射治疗,观察组术后给予地佐辛关节腔内注射。比较两组患者术后视觉模拟评分法(VAS)评分、膝关节功能、膝关节功能优良率及并发症发生率。结果观察组术后6、24小时的VAS评分均低于对照组,差异有统计学意义(P0.05);术后1个月,观察组膝关节功能中疼痛指标明显低于对照组,关节功能、活动度、肌力、屈曲畸形和稳定性均明显高于对照组,且膝关节功能优良率明显高于对照组,差异具有统计学意义(P0.05);观察组肿胀、慢性疼痛、活动受限的总发生率明显低于对照组,差异具有统计学意义异具有统计学意义(P0.05)。结论地佐辛关节腔内注射对膝关节镜术后镇痛效果显著,值得推广。     

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

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。     

氢吗啡酮复合纳布啡用于胃肠道手术后PCIA的效果

目的评价氢吗啡酮复合纳布啡用于胃肠道手术后病人自控静脉镇痛(PCIA)的效果。方法择期行胃肠道手术病人600例,年龄18～80岁,BMI≤35 kg/m2,ASA分级Ⅰ～Ⅲ级。按随机数字表法将病人分为2组(n=300):氢吗啡酮组(H组)和舒芬太尼组(S组)。术后48 h内采用PCIA,H组配方为氢吗啡酮10 mg+纳布啡40 mg;S组配方为舒芬太尼100 μg+纳布啡40 mg。2组药物均加生理盐水稀释至100 ml,背景剂量1 ml/h,单次剂量0.5 ml。记录病人术后48 h内VAS评分、镇痛有效按压次数、镇痛泵用药量、不良反应及术后恢复情况。结果 2组术后48 h内VAS评分、镇痛泵用药量和镇痛泵有效按压次数比较差异无统计学意义(P>0.05)。与S组比较,H组术后48 h内头晕、恶心、呕吐发生率降低,首次下床时间缩短(P<0.05)。结论氢吗啡酮复合纳布啡用于胃肠道手术后PCIA的效果优于舒芬太尼复合纳布啡。     

多模式镇痛用于膝关节镜下交叉韧带重建术临床分析

目的探讨围术期多模式超前镇痛在膝关节镜手术应用的镇痛效果。方法行膝关节镜下交叉韧带重建术患者60例,随机分为A组与B组,每组30例。两组均采用腰硬联合麻醉,A组为多模式超前镇痛组,在术前30分钟肌注帕瑞昔布钠40 mg,B组患者肌注等量生理盐水。手术后A组患者在B超引导下行单次股神经阻滞(0.2%罗哌卡因25 m1)。B组患者在术后给予硬膜外注射吗啡2 mg。两组均带自控镇痛泵,2 mL/h,每次追加0.5 ml,锁时15分钟。术后12小时A组患者肌肉注射帕瑞昔布钠40 mg,B组患者肌注等量生理盐水。记录术后6小时、12小时、1天和2天的膝关节疼痛视觉模拟评分(visual analogue scale,VAS)、股四头肌肌力、自控镇痛泵按压次数和不良反应发生情况。结果 A组在术后6小时、12小时和1天的VAS评分和自控镇痛泵按压次数均显著低于B组(P0.05),两组术后2天的VAS评分和自控镇痛泵按压次数比较,差异无统计学意义(P0.05),两组术后各时间点股四头肌肌力比较,差异无统计学意义(P0.05)。A组术后发生不良反应例数明显低于B组(P0.05)。结论多模式超前镇痛在膝关节镜下交叉韧带重建术的镇痛效果明显优于传统硬膜外给予吗啡的方法,不良反应发生率低。     

Comparison of the analgesic efficacy and plasma concentrations of high-dose intra-articular and intramuscular morphine for knee arthroscopy

BACKGROUND AND OBJECTIVE: It is important to provide good postoperative analgesia after discharge from day case surgery. The usefulness of intra-articular morphine for analgesia after day case knee arthroscopy remains controversial. A large dose of morphine intra-articularly may provide a good long-lasting analgesia, but its efficacy and pharmacokinetics are not known and may be no better than intramuscular morphine. We compared the effect of 10 mg intra-articular and intramuscular morphine for 24 h post-injection in a randomized double-blind study. METHODS: Forty adults undergoing knee arthroscopy were recruited and received either 10mg morphine intra-articularly or intramuscularly. Our primary outcome was overall visual analogue assessment of pain (0-100 mm scale where 0 is no pain and 100 is worst possible pain) between 4 h (on discharge) and 24 h (post-operatively). Plasma morphine concentrations were measured at 15 min, and 1, 2, 4 and 24 h. The use of additional analgesia was noted. RESULTS: The assessment of pain experienced between discharge (4 h) and 24 h was significantly better in the intra-articular (n = 20; mean+/-SD: 18+/-19) than the intramuscular (n = 19; mean+/-SD: 34+/-20) group (P = 0.027). The number of patients consuming any additional analgesia between discharge and 24 h was significantly lower in the intra-articular morphine group (P = 0.038), with 4 (20%) patients in the intra-articular group and 11 (60%) patients in the intramuscular group consuming supplementary analgesia. There were no differences in plasma morphine concentrations between the groups. CONCLUSIONS: A large dose of intra-articular morphine provided better analgesia than the same dose of intramuscular morphine, low plasma morphine levels suggesting a peripheral mechanism.     

右美托咪定对患者膝关节腔注射罗哌卡因镇痛ED_(50)的影响

目的观察右美托咪定对罗哌卡因膝关节腔注射用于老年患者膝关节镜术后镇痛ED_(50)的影响。方法选择择期行膝关节镜诊治术老年患者72例,男35例,女37例,年龄60~75岁,ASAⅠ或Ⅱ级。随机分为罗哌卡因组(R组)和右美托咪定复合罗哌卡因组(DR组),每组36例。R组患者膝关节腔内注射不同浓度罗哌卡因;DR组患者关节腔内注射不同浓度罗哌卡因和右美托咪定1μg/kg的混合液。术后2hVAS评分低于3分为镇痛有效。采用序贯法确定罗哌卡因浓度,初始浓度为0.15%,相邻浓度比值为1.1,镇痛有效则下一例采用低一级浓度,镇痛无效则下一例采用高一级浓度。采用Dixon-Massey法确定ED_(50)及其95%CI。记录术前5min(T_0)、术后1h(T_1)、2h(T_2)、3h(T_3)、6h(T_4)、12h(T_5)、24h(T_6)和48h(T_7)患者BP和HR,并对患者进行改良的OAA/S评分和VAS评分。结果术前和术后各时点两组患者BP、HR、VAS评分和OAA/S评分差异均无统计学意义。C组ED_(50)为0.31%(95%CI 0.30%~0.32%);DR组ED_(50)为0.14%(95%CI 0.14%~0.15%)。结论右美托咪定可增强罗哌卡因膝关节腔注射用于患者膝关节镜术后镇痛的效果,并可减少罗哌卡因的用药剂量。     

Low-dose intra-articular ketorolac for pain relief following arthroscopy of the knee joint

The systemic administration of nonsteroidal anti-inflammatory agents has been shown to improve analgesia following arthroscopy of the knee joint. Ketorolac 60 mg, when given intra-articularly, provides better postoperative analgesia than an identical dose administered systemically. We compared the postoperative analgesic effect of ketorolac 10 mg given intravenously with 5 mg intra-articularly in 60 patients undergoing arthroscopy of the knee joint under general anaesthesia. Patients were randomly allocated in a double-blind manner to receive 0.25% bupivacaine 20 ml and ketorolac 5 mg intra-articularly (n = 27) or intravenous ketorolac 10 mg followed by 0.25% bupivicaine 20 ml (n = 30) at the end of surgery. There were no differences between the groups in terms of their physical characteristics or in the nature of procedure performed. There was no statistical difference between the two groups in time to first analgesia or postoperative visual analogue pain scores at 1, 2 and 4 h (p = 0.6). The median consumption of a standard analgesic was reduced in the intra-articular group in the second 24-h period but this did not achieve statistical significance (p = 0.08). Only five patients in total needed postoperative morphine. A reduced amount of locally applied ketorolac (5 mg) provides similar analgesia to a higher systemic dose (10 mg) following knee arthroscopy.     

Intra-articular morphine enhances analgesic efficacy of ropivacaine for knee arthroscopy in ambulatory patients

The aim of this double-blind, randomized control trial was to compare the effectiveness of intra-articular ropivacaine alone or with morphine or ketoprofen for controlling pain after arthroscopic knee surgery. One hundred fifty-six patients scheduled for elective knee arthroscopy were recruited. All patients received general anesthesia and were randomly assigned to 4 groups to receive intra-articular ropivacaine 40 mg (group R), ropivacaine 24 mg plus morphine 8 mg (group R+M), ropivacaine 36 mg plus ketoprofen 100 mg (group R+K), or normal saline (group N/S). Pain, sedation, orientation, nausea, vomiting, and urine retention were recorded at 0, 1, 2, 4, 8, 12, and 24 hours postoperatively. Pain was evaluated by a 10-cm visual analog scale (VAS). When the pain was >2, a suppository of 400 mg paracetamol plus 10 mg codeine plus 50 mg caffeine was given. Results showed that at 4 hours postoperatively, pain differed significantly among the 4 groups (P<.001), with less pain recorded in the R+M group. Similarly, the number of suppositories administered postoperatively to the R+M group was significantly less (P<.001) vs the other groups. Patients who received ropivacaine and morphine or normal saline had a higher incidence of nausea and vomiting vs the other groups (P=.001 and P=.036, respectively). The combination of intra-articular ropivacaine and morphine is associated with less pain after knee arthroscopy during early recovery but with a higher incidence of nausea and vomiting. However, the addition of ketoprofen to ropivacaine provides relatively satisfactory pain relief, but with fewer side effects compared to morphine.     

Combination of intra-articular tenoxicam, lidocaine, and pethidine for outpatient knee arthroscopy

BACKGROUND: Studies of intra-articular non-steroidal anti-inflammatory drugs have revealed an analgesic effect equivalent to that of intra-articular local anaesthetic agents and morphine. The aim of this study was to evaluate the analgesic effect of intra-articular lidocaine, pethidine and tenoxicam compared with that of lidocaine and pethidine on postoperative pain after arthroscopy. METHODS: After day-case knee arthroscopy, 60 patients were randomly allocated to one of three groups to receive 20 ml of a solution containing 0.9% saline (group S), 2% lidocaine and 10 mg preservative-free pethidine (group LP) and 2% lidocaine, 10 mg preservative-free pethidine and 20 mg tenoxicam (group LPT). Postoperative pain was assessed using a visual analogue scale and measuring analgesic requirements. RESULTS: Pain scores were significantly lower in the LP group than in the S group at 1 and 2 h after surgery. From 4 h until the end of the first postoperative day, pain scores were significantly lower in the LPT group of patients at rest and on knee flexion than in the other two groups; these patients also used less oral analgesics (P<0.05). CONCLUSION: The combination of 20 ml lidocaine 2%, 10 mg pethidine and 20 mg tenoxicam given intra-articularly provided superior analgesia and reduced oral analgesic requirement during the first day after arthroscopy compared with lidocaine and pethidine alone.     

Comparisons of analgesic effects of different doses of morphine and morphine plus methylprednisolone after knee surgery

BACKGROUND: In this double-blind randomized study, the analgesic effects of morphine alone and with methylprednisolone were examined in 72 patients undergoing arthroscopic knee surgery. METHODS: At the end of arthroscopy, patients were allocated randomly to one of four groups to receive intra-articular administrations of saline, morphine 1 mg, morphine 5 mg or morphine 1 mg with methylprednisolone 40 mg. Preoperative and postoperative pain levels at rest and during movement (active flexion of the knee) were measured by a visual analogue scale (VAS). Postoperative analgesic requirements to alleviate pain were evaluated. RESULTS: Pain scores were significantly lower for the patients who received 5 mg morphine and 1 mg morphine with 40 mg methylprednisolone than for those who received saline or 1 mg morphine. This was accompanied by a decrease in the postoperative consumption of analgesics and prolongation of the duration of pain relief. CONCLUSIONS: This study confirms that the analgesic effect of morphine given intra-articularly is dose dependent and that combination of methylprednisolone with morphine has an additive effect on analgesia.     

布托啡诺与吗啡用于腹部手术后硬膜外镇痛效果的比较

目的 研究不同剂量布托啡诺用于腹部手术患者术后硬膜外镇痛的效果及副作用,并与吗啡硬膜外镇痛进行比较. 方法 择期腹部手术ASAⅠ～Ⅱ级患者75例,按术后镇痛用药不同随机分为3组(n=25):M组(吗啡12 mg+0.1%罗哌卡因共150ml),B1组(布托啡诺9mg+0.1%罗哌卡因共150 ml),B2组(布托啡诺12mg+0-1%罗哌卡因共150ml).负荷量为0.25%罗哌卡因5 ml加吗啡2 mg或布托啡诺2 mg,持续背景输注剂量均为1-5 ml/h,按压追加药量均为2 ml/次,按压锁定时间20 min.观察记录3组患者术中芬太尼的总药量;术后1、4、8、12、18、24、36、48 h各时间点的疼痛视觉模拟评分(pain visual analogue scores,VAS);术后1、4、8、12 h的警觉镇静评分(observer's assessment ofalertness/sedation scores,OAA/S);术后48 h内按压总次数及总药量;肛门排气时间;术后镇痛副作用(头痛头晕、嗜睡、呼吸抑制、搔痒、恶心、呕吐、腹胀)的发生情况.结果 术后4 h时间点B1组VAS评分为2.8±1.0,高于M组的2.0±0.7及B2组的2.0±0.9(P<0-05),其余时间点3组间比较差异无统计学意义(P>0.05).M组的头痛头晕、恶心、呕吐,腹胀,搔痒发生例数分别为3、11、7、4、5例,而B1组仅有1例头痛头晕,B2组有2例头痛头晕,1例恶心,发生率均低于M组(P<0.05).3组患者术中芬太尼的总药量、48 h内按压总次数及总药量、术后不同时间点OAA/S评分及肛门排气时间的比较差异无统计学意义(P>0.05). 结论 每天3 mg～4 mg布托啡诺应用于腹部手术后硬膜外镇痛,镇痛效果确切,且其副作用发生率较吗啡明显降低.     

Intra-synovial, compared to intra-articular morphine provides better pain relief following knee arthroscopy menisectomy

PURPOSE: To evaluate the analgesic effect of morphine 1 mg administered into the synovial tissue and the outer third of the meniscus after knee arthroscopy. METHODS: In a prospective, double-blind, randomized study, 60 patients who required elective knee arthroscopy were assigned to two groups: Group A consisted of 30 patients who received a direct injection of morphine 1 mg into either the synovial tissue or the outer third of the meniscus following menisectomy. Group B consisted of 30 patients who received a direct injection of NaCl 0.9% 1 mL into the synovial tissue or the outer third of the meniscus following menisectomy. At the end of the operation Group A received an intra-articular injection of NaCl 0.9% 1 mL and bupivacaine 0.5% 10 mL and Group B received an intra-articular injection of morphine 1 mg and bupivacaine 0.5% 10 mL. Analgesic effect was evaluated by pain intensity (visual analogue scale; VAS) and analgesic requirements (paracetamol) during the first one, three, six, 12, 24, and 48 hr postoperatively. RESULTS: There was no significant difference between the two groups within the first six hours and after 24 hr following the operation regarding VAS score and analgesic requirements. At 12 and 24 hr following the operation, the VAS score and the analgesic requirements were significantly higher in Group B compared to Group A (P <0.01 and P <0.01, respectively). No patient developed side effects. CONCLUSION: We conclude that direct morphine injection into the synovia or the outer third of the meniscus provided better pain relief than intra-articular morphine after knee arthroscopy.     

Intra-articular clonidine analgesia after knee arthroscopy

Recently, it was suggested that peripherally-mediated analgesia can be accomplished by the intra-articular delivery of the mu-opioid morphine or of the a2-agonist clonidine. This clinical study assesses the potential peripheral analgesic effect of the combination of morphine and clonidine after intra-articular administration. Sixty patients (American Society of Anesthesiologists status I or II) undergoing arthroscopic repair of the knee during general anaesthesia were randomized to receive after operation, in a double-blind manner, either 1 mg morphine intra-articularly (group 1); 150 microg clonidine intra-articularly (group 2); or 1 mg morphine + 150 microg clonidine intra-articularly (group 3); or normal saline intra-articularly (group 4) in a volume of 30 mL, respectively. Visual analogue pain scores (VAS), duration of analgesia as defined by first demand for supplemental analgesics, subsequent 24 h consumption of postoperative supplementary analgesics, and patient satisfaction were evaluated. Co-administration of morphine + clonidine (group 3) resulted in a significant VAS reduction at 2 h after injection compared with the other groups. There was a tendency towards a lower need for supplementary rescue analgesia and towards a more prolonged analgesia in group 3 (211 min +/- 224 min SD) compared with group 1 (173 min +/- 197 min SD) and group 4 (91 min +/- 21 min SD). More patients were very satisfied with the postoperative analgesic regimen receiving the combination of morphine and clonidine (group 3) at 24 h postoperatively. Thus we conclude, that the peripheral co-delivery of an opioid and an a2-agonist will result in improved postoperative pain relief, when compared with each single agent given alone.