Background and Objective: Various adjuvants are being used with local anaesthetics for prolongation of intraoperative and postoperative analgesia in epidural block for lower limb surgeries. Dexmedetomidine, a highly selective α2-adrenergic agonist, is a new neuraxial adjuvant gaining popularity. The aim of the present study was to compare the efficacy, bispectral index (BIS) value, and haemodynamic spectrum of epidurally administered dexmedetomidine when combined with ropivacaine and levobupivacaine in long bone surgeries. Material and Methods: This prospective, randomized, double-blind study included 120 patients of American Society of Anaesthesiologists (ASA) Grade I and II, aged 18-65 years of either sex, undergoing lower limb surgeries after informed consent. Patients were randomized into two groups of 60 each: Group RD received 22 ml of 0.75% ropivacaine with dexmedetomidine (1 μg/kg), and Group LD received 22 ml of 0.5% levobupivacaine with dexmedetomidine (1 μg/kg). Groups were compared for haemodynamic changes, block characteristics (time to onset of analgesia at T10, maximum sensory level, time to maximum sensory and motor block, regression to S1 dermatome, and time to first rescue analgesia). Data were analyzed using Chi-square test, Fisher’s exact test, and Student t-test. P < 0.05 was significant, and P < 0.001 highly significant. Results: Group LD demonstrated longer sensory blockade (409.5 ± 38.7 min vs. 385.2 ± 36.8 min; p < 0.001), while Group RD showed prolonged motor blockade (395.4 ± 0.8 min vs. 299.4 ± 0.4 min; p < 0.001). Onset of sensory block was faster in Group LD (6.4 ± 1.0 min vs. 6.8 ± 1.0 min; p = 0.039). Time to rescue analgesia was longer with levobupivacaine (411 ± 0.7 min vs. 390.6 ± 72 min; p = 0.044). BIS values and haemodynamics remained comparable, with only minor, clinically manageable variations. Conclusion: Both regimens provided effective epidural anaesthesia with stable haemodynamics and minimal side effects. Levobupivacaine with dexmedetomidine yielded a longer sensory block and delayed rescue analgesia, whereas ropivacaine with dexmedetomidine produced a denser motor blockade. BIS changes were insignificant in both groups.
Thakur et al. (Wed,) studied this question.