ABSTRACT
The frist successful trial of extradural opioids injection was in Jerusalem[1]. Chronic pain was magaged extradurally at first by 2 mg morphine. Up to 10 mg morphine was used extradurally with very good analgesia but on the expense of severe respiratory depression[2]. Morphine can be detected in the cerebrospinal fluid it is injected in such a high dose[3]. Many trials was performed to use morphine in the extradural space for postoperative pain relief, with gradually decreasing dose in order to obtain pain relief with prevention of respiratory depression[4]. Extradural morphine 2 mg did not produce sufficient pain relief following caeserian section[5]. Morphine 3 mg injection in the extradural space can be effective in postoperative pain relief as previously reported[6]. Many factors may contribute to the effect of extraduraI opioids as the direct dural effect, fat deposition and systemic absorbtion. To reduce the incidence of respiratory depression it was suggested to use lipid. Isoluble drug, as buprenorphine, as this agent enter the neural tissue rather than it remains in the cerebrospinal fluid. When buprenorphine is injected in the extradural space a higher dose is required to compensate for deposition in fat and systemic absorbtion[7]. A dose of 0.1 mg buprenorphine was suggested as the optimum extradural dose for the relife of postoperative pain[8]. Because of the high lipid solubility of buprenorphine it has been suggested that its extradural dose is similar to the intravenous one[8]. Because of the high lipid solubility of buprenorphine it has been suggested that its extradural dose is similar to the intravenous one[9]. On intramuscular administration a dose of 0.09 mg of buprenorphine is equipotent to 3 mg morphine[9]. In the present study we compared 3 mg morphine with buprenorphine 0.09 mg extradurally for post operative pain relieve after transurethral prostatectomy [TUR]. A larger dose of buprenorphine [0.18 mg] was also studied