COMPARISON OF COMBINATION OF ISOBARIC LEVOBUPIVACAINE AND HYPERBARIC LEVOBUPIVACAINE VERSUS HYPERBARIC LEVOBUPIVACAINE IN SPINAL ANAESTHESIA FOR INGUINAL HERNIA SURGERY TO DETERMINE THE ONSET OF BLOCK: A RANDOMIZED CONTROL TRIAL

Abstract

Introduction: Spinal anaesthesia is the preferred regional technique for inguinal hernia surgeries due to its rapid onset, reliable sensory and motor blockade, and favorable safety profile. Levobupivacaine, available in both isobaric and hyperbaric formulations, is widely used, but the optimal combination for achieving faster onset of block remains unclear. This study aimed to compare the onset of sensory and motor blockade between a combination of isobaric and hyperbaric levobupivacaine versus hyperbaric levobupivacaine alone in patients undergoing inguinal hernia repair. Methodology- This randomized controlled trial was conducted over 18 months in 100 patients. Patients were randomly assigned to receive either a combination of isobaric (0.4 mL) and hyperbaric (2.6 mL) levobupivacaine (Group A) or hyperbaric levobupivacaine alone (3 mL, Group B) via intrathecal injection at L3–L4. Sensory block was assessed by loss of pinprick sensation to T8, and motor block was evaluated using the Modified Bromage Scale. Hemodynamic parameters and adverse effects were monitored perioperatively, and the onset, maximum level, duration, and regression of sensory and motor block were recorded. Result- Primary outcome (sensory onset to T8) 5.57 ± 0.99 minutes (Group A) vs 4.15 ± 0.77 minutes (Group B); p < 0.001. Motor onset (time to Bromage 3) 7.69 ± 1.47 minutes (Group A) vs 5.87 ± 1.01 minutes (Group B); p < 0.001. Group B provided faster onset and longer duration of sensory and motor block, while Group A demonstrated better hemodynamic stability. Conclusion- The combination of isobaric and hyperbaric levobupivacaine offers a more controlled block with lower hypotension incidence, making it preferable when haemodynamic stability and early recovery are priorities.