COMPARATIVE EFFECT OF INTRATHECAL HYPERBARIC LEVOBUPIVACAINE VERSUS BUPIVACAINE WITH MIDAZOLAM AS ADJUVANT IN LOWER LIMB SURGERY

Abstract

Background and Objectives: The search for a cardio-stable local anaesthetic with a superior safety profile has led to the increased use of levobupivacaine. This study aimed to compare the clinical efficacy and safety of hyperbaric levobupivacaine versus hyperbaric bupivacaine, both using midazolam as an intrathecal adjuvant, in patients undergoing lower limb surgeries. Materials and Methods: In this prospective, randomized, double-blind study, 60 ASA I and II patients aged 15–75 years were divided into two equal groups (n=30). Group B received 2.8 ml of 0.5% hyperbaric bupivacaine with 1 mg preservative-free midazolam, while Group L received 2.8 ml of 0.5% hyperbaric levobupivacaine with 1 mg midazolam. The primary objective was to compare the onset of sensory and motor blockade. Secondary objectives included the assessment of hemodynamic changes, duration of analgesia, sedation levels (OAA/S scale), and the incidence of adverse effects. Results: The mean time to sensory block onset at the T10 level was significantly faster in Group B (3.2 ± 0.92min) than in Group L (4.06 ± 1.14 min; p=0.002). However, motor block onset times (4.69 vs. 5.00 min; p=0.36) and total duration of motor blockade (3.21 vs. 3.2 hours; p=0.95) were comparable. Group L demonstrated significantly greater hemodynamic stability, maintaining higher Mean Arterial Pressure (MAP) at 20, 60, 150, 180, and 240 minutes (p<0.05). The total duration of analgesia was similar in both groups (Group B: 3.91 hrs; Group L: 4.2 hrs; p=0.38). No significant sedation or adverse effects were observed in either group. Conclusion: Hyperbaric levobupivacaine with intrathecal midazolam provides an effective anaesthetic block for lower limb surgery with superior hemodynamic stability compared to racemic bupivacaine. While bupivacaine offers a marginally faster sensory onset, levobupivacaine is a safer alternative for maintaining cardiovascular consistency while providing equivalent postoperative analgesia.