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Background and Aims: Bupivacaine and lidocaine mixtures are the commonly used local anesthetic drugs for the peribulbar blocks. Because of its safe anesthetic profile, ropivacaine is being investigated as an alternative agent. Several centers have evaluated the effect of the addition of an adjuvant like dexmedetomidine (DMT) to ropivacaine in enhancing the block characteristics. We proposed to evaluate the effect of the addition of DMT to ropivacaine versus a control group not having DMT as adjuvant. Material and Methods: A prospective, randomized comparative study was conducted on a total of 80 patients attending our hospital for cataract surgeries. Patients were allocated into four groups of 20 each (n = 20) and peribulbar blocks were given 6 mL of 0.75% ropivacaine in group R and 6 mL of 0.75% ropivacaine plus 10 μg, 15 μg, and 20 μg DMT, respectively, in groups RD1, RD2, and RD3. Results: When DMT was used as an adjunct to ropivacaine, there was a prolongation of the duration of the sensory block. Conclusion: In peribulbar blocks, 6 mL of ropivacaine 0.75% produces satisfactory block characteristics, and the addition of 10 μg, 15 μg, or 20 μg of DMT as an adjuvant to ropivacaine 0.75% had the effect of significantly prolonging the duration of the sensory block, which is directly proportional to the dose of DMT employed. However, 20 μg of DMT added as an adjuvant to ropivacaine 0.75% appears to be the optimal dose, as this anesthetic drug mixture provides maximum prolongation of the sensory block besides providing satisfactory operating conditions, acceptable sedation levels, and stable hemodynamic parameters.

Background and Aims: Cataract surgery in ophthalmology is usually done under peribulbar block with a mixture of 0.5% bupivacaine and 2% lidocaine. Several case reports of fatalities associated with bupivacaine has necessitated a search for alternative safe agents. The aim of this study was to compare peribulbar block characteristics using a mixture of 0.5% bupivacaine and 2% lidocaine with a mixture of 0.5% ropivacaine and 2% lidocaine. Material and Methods: Eighty patients were allocated to two random groups of 40 each. Patients of groups BL and RL were given 4 ml of 0.5% bupivacaine and 4 ml of 0.5% ropivacaine each in a mixture with 4 ml of 2% lidocaine and 100 IU of hyaluronidase respectively. Block characteristics, hemodynamic variables, adverse drug interactions and other complications were recorded. Results: Demographic characteristics were comparable in both the groups. Duration of onset of the block and the side effect profile was comparable in both the groups but the total duration of the block and the time for first rescue analgesia was found to be longer in group BL than in group RL. Conclusions: Ropivacaine 0.5% and lidocaine 2% as a 1:1 mixture in a volume of 8 ml with 100 IU of hyaluronidase is as effective as a 1:1 mixture of bupivacaine 0.5% and lidocaine 2% in a volume of 8 ml with 100 IU of hyaluronidase with regards to onset and total duration of the block and side effects and hemodynamic changes.