Enhancing Spinal Anesthesia for Lower Limb Surgeries: A Comparative Study of Intrathecal Midazolam and Hyperbaric Bupivacaine

Background: Spinal anesthesia is a critical technique for lower limb surgeries, offering rapid onset and reliability. However, the limited duration of anesthesia and postoperative analgesia with bupivacaine presents a clinical challenge. This study investigates the efficacy of adding preservative-free midazolam to hyperbaric bupivacaine to enhance the analgesic profile of spinal anesthesia. Methods: This prospective, randomized, single-blinded study involved 60 patients undergoing elective lower limb surgeries, divided into two groups. Group B received 3 ml of 0.5% hyperbaric bupivacaine, and Group B+M received the same dose of bupivacaine plus 0.2 ml (1 mg) preservative-free midazolam. The study assessed the onset and duration of sensory and motor block, the duration of postoperative analgesia, and the incidence of side effects. Results: There was no significant difference in demographic and baseline characteristics between the groups. However, Group B+M demonstrated a significantly longer duration of analgesia (218.5 ± 22.52 minutes) compared to Group B (171.5 ± 18.76 minutes) (p<0.001). The incidence of side effects such as nausea, vomiting, and respiratory depression showed no significant difference between the groups. Conclusion: The addition of preservative-free midazolam to hyperbaric bupivacaine significantly extends the duration of analgesia without increasing the risk of major complications, suggesting a valuable enhancement to spinal anesthesia for lower limb surgeries.