Intrathecal midazolam is a comparable alternative to fentanyl and nalbuphine as adjuvant to bupivacaine in spinal anesthesia for elective cesarean section: a randomized controlled double-blind trial

Background: Different adjuvants have been introduced to enhance the quality of local anesthetics and reduce its adverse events. This study was directed to compare the anesthetic and analgesic properties of intrathecal hyperbaric bupivacaine when three different adjuvant drugs were added.Methodology: One hundred full-term parturients aged 18 to 40 years, scheduled for elective cesarean section, were randomly assigned to 4 groups. Each group received 12.5 mg of 0.5% hyperbaric bupivacaine combined with either 0.5 ml saline (Group-B), 25 mu g fentanyl (Group-F), 0.8 mg nalbuphine (Group-N) or 2 mg midazolam (Group-M). The outcomes included the postoperative effective analgesia time, the sensorimotor characteristics, postoperative VAS score, pethidine consumption, maternal complications, and neonatal Apgar score.Results: Earlier onset of sensory and motor block was observed in Group F and N than in Group B and M. Duration of postoperative effective analgesia was longer in Groups F, N and M (252.42 +/- 46.11, 227.34 +/- 36.54 and 243.71 +/- 44.95 hours, respectively) than in Group B (172.11 +/- 20.99) (P < 0.001). VAS scores decreased in adjuvant groups during the first 12 hours postoperative and required pethidine doses were less.Conclusion: Addition of adjuvant agents to intrathecal bupivacaine improved the quality of subarachnoid block without increasing side-effects. Intrathecal midazolam provided comparable outcomes as the frequently used opioids.