The adjunctive midazolam or magnesium sulfate to intrathecal bupivacaine analgesic effect in caesarean section: a randomized controlled trial

Background: Pain modulation is very important after operation, particularly for women who undergo caesarean section. Physiologic and psychological problems are the consequences of the improper pain management which raise the healthcare costs and prolong the recovery process. Objectives: The aim of the present work is to assess the analgesic effect of combination of intrathecal midazolam or magnesium sulfate with bupivacaine in comparison to bupivacaine alone in parturient women who are candidate for non-emergent caesarean section. Methods: Current study is a randomized controlled trial. 93 parturient women who were candidate for non-emergent caesarean section were selected. All individuals signed a written consent. By random block allocation they were divided to 3 groups. 10 mg bupivacaine 0.5% along with 2 mg midazolam intrathecally was administered for one group. An intrathecal injection of 10 mg bupivacaine 0.5% in addition to 100 mg magnesium sulfate was administered for second group. And finally the control group received an intrathecal injection of 10 mg bupivacaine 0.5% with 1 ml normal saline. The postoperative analgesic period, mean arterial pressure, heart rate, and frequency of nausea and vomiting were evaluated in 3 groups. Results: The mean time from the anesthesia to start of pain sensation and demand for the first dose of analgesic was longer in midazolam and magnesium sulfate groups in comparison to the control group, although it wasn't statistically significant. Furthermore, there was no significant difference between the pain-free parturient rates also the pain severity was not significantly different between the three groups 4 h after caesarean section. Hemodynamic changes such as mean arterial pressure and heart rate, the postoperative nausea and vomiting rate and the mean first and fifth minutes Apgar score did not differ in 3 groups. Conclusion: The present work showed no benefit for intrathecal midazolam or magnesium sulfate combined with bupivacaine in women who undergo caesarean section.