Comparison of analgesic effects of epidural morphine and epidural non-morphine drugs

本研究旨在研制临床有效的硬膜外非吗啡用于术后镇痛，其结果和结论如下：1)硬膜外吗啡对大鼠躯体和内脏疼痛均有效。相比之下，硬膜外注射美度托咪定(一种镇静剂)、咪达唑仑(一种镇静剂)、氯胺酮(一种麻醉剂)和非吗啡阿片类药物(布托啡诺和丁丙诺啡)只能产生轻度到中度的镇痛。2)硬膜外注射大剂量局麻药(利多卡因和布比卡因)可产生较强的镇痛作用，但镇痛持续时间短，可引起严重的盆腔肢体共济失调。小剂量布比巴卡因、布托啡诺或丁丙诺啡联合应用可有效缓解躯体或内脏疼痛，且无明显共济失调。3)硬膜外吗啡或布比卡因与丁丙诺啡联合用于临床各种手术后的疼痛控制效果良好。虽然布比卡因的剂量比上述结果估计的剂量更大，但硬膜外布比卡因和丁丙诺啡在犬的病例中引起了轻微的共济失调。结论：硬膜外布比卡因和丁丙诺啡用于犬手术后镇痛是有效的。

This study was designed to develop the clinically effective epidural non-morphine for post-operative analgesia and the followings are the results and conclusion.1) Epidural morphine was effective for both somatic and visceral pain in rat model. In contrast, epidural administration of medetomidine (a sedative), midazolam (a tranquilizer), ketamine (an anesthetic), and non-morphine opioids(butorphanol and buprenorphine)induced only mild to moderate analgesia. The combinations of these drugs except for morphine were not also very effective for analgesia.2) Epidural administration of high dose of local anesthetics(lidocaine and bupivacaine)induced potent analgesia, however the duration of analgesia was short and caused severe ataxia of pelvic limbs. The combinations of low dose of bupibavacaine and butorphanol or buprenorphine induced potent analgesia against either somatic or visceral pain without apparent ataxia. These combinations, especially the combination of bupivacaine and buprenorphine may be a substitute of morphine when used epidurally.3) Epidural morphine or bupivacaine and buprenorphine were effective for post-operative pain management in clinical cases that were underwent various surgery. Although the higher dose of bupivacaine than the dose which was estimated from the results obtained above was needed, epidural bupivacaine and buprenorphine caused mild ataxia in dog cases. In conclusion, epidural bupivacaine and buprenorphine is effective for post-operative analgesia in dogs.