The effect of adding intrathecal magnesium sulphate to bupivacaine in spinal anesthesia

Background:spinal anesthesia with use of local anesthetic drugs and opioid has been noted in compare with general anesthesia because of its high success ,satisfication of patients and low access of drugs recently.opiods although prolong duration of analgesia but its use has limited by its side effect such as pruritus ,respiratory depression,nausea and vomiting.use of intrathecal magnesium sulphate has realy shown to prolong the duration of analgesia in spinal anesthesia in recent clinical trial. In this study,we evaluated the efficacy of adding intrathecal magnesium sulphate to bupivacaine in patients under lower extremity surgery with spinal anesthesia. Materials and metods:in this prospective randomization triple blind study we enrolled 80patient undergoing lower orthopedic surgery in fatemi hospital with spinal anesthesia in 2013-214 .they randomly divided in two group .first group(s) recived 3 ml bupivacaine 0/5% plus 1ml salin and other group (M) recived 3 ml bupivacaine 0/5% plus 1 ml magnesium sulphate 5% (50 mg).The Onset and duration of sensory and motor block ,side effects,sedation score and duration of postoperative analgesia requirements were studied in two group.informations collected in check list and then data were analysed by SPSS software with chi-square and T-test and analysis of variance. Results: The onset time of both sensory(5/90 vs .2/90 min) and motor block(8/18 vs. 4/78 min) was delayed in the magnesium group(p05).The first postoperative analgesia requirements was significantly(p