Comparative Study of Intrathecal Midazolam Used as Adjuvant to Intrathecal Bupivacaine with Intrathecal Bupivacaine Alone in Orthopedic Surgeries

Background: Spinal anesthesia is a common technique used in orthopedic surgeries involving hip and lower limbs. It provides adequate analgesia both intra and post-operative and it also avoids complications associated with general anesthesia. Spinal block remains the first choice in these kinds of surgeries due to its rapid onset, superior blockade, less failure rates and cost effectiveness, but has the drawbacks of shorter duration of block and lack of postoperative analgesia. Use of intrathecal adjuvants has gained popularity with the aim of prolonging the duration of block, better success rate and patient satisfaction. Methods: 60 patients, ASA I/II were enrolled into the study. All patients had spinal anesthesia and randomly allocated into one of two groups. Group C: (30 patients): The patient received 15mg of bupivacaine 0.5% plus 0.4ml saline, Group M: (30 patients): The patient received 15mg of bupivacaine 0.5% plus 0.4ml of midazolam (2mg). In both groups assessment was done for time to reach T10 dermatome, time to peak sensory level, time to reach complete motor block (Bromage 3), regression to SI dermatome and time for motor recovery. Results: This study demonstrated that the Midazolam group was associated with increased sensory block time with no increase neither in onset nor in motor block duration. Hemodynamic variables were stable and there were no significant differences between both groups. Conclusion: Finally, it is concluded that Midazolam (2mg) is effective as useful adjuvant to Bupivacaine for intrathecal anesthesia. Midazolam increased the duration of sensory block but with less duration of motor block. Midazolam also reduced intraoperative shivering with no significant side effects.