Abstract
Background: Dexmedetomidine, a selective α2-adrenergic agonistic provides additional analgesic action along with local anaesthetics in spinal anaesthesia.
Aims and Objectives: To assess the analgesic and hemodynamic effects of intrathecal administration of Ropivacaine 0.75% alone versus Ropivacaine 0.75% with 5 mcg of Dexmedetomidine in elective lower limb orthopedic surgeries.
Material and Methods: After approval of ethical committee, 120 patients who were scheduled for elective lower limb orthopedic surgeries were selected and randomized in 2 groups: In , Group 1, 3 ml volume of 0.75% isobaric Ropivacaine with 0.5ml normal saline to make 3.5ml , was administered . In Group 2 , 3 ml volume of 0.75% isobaric Ropivacaine with 5 μg Dexmedetomidine to make a volume of 3.5ml was administered .Onset of sensory block , analgesic effects and hemodynamic effects were compared between the 2 groups.
Results: Onset of sensory bock was 5.17 ± 0.7 minutes for only Ropivacaine group and 4.63 ± 0.61 for Ropivacaine with Dexmedetomidine group. Time taken by block to reach maximum level was 11.87 ± 1.36 minutes for only Ropivacaine group and 11.68 ± 1.24 minutes for Ropivacaine with Dexmedetomidine group. Time taken by block for two segment regression from highest sensory level was 65.3 ± 1.68 minutes for only Ropivacaine group and 125.87 ± 1.74 minutes for Ropivacaine with Dexmedetomidine group. Mean time of required for first dose of rescue analgesia was 244.33 ± 2.83 minutes for only Ropivacaine group and 466.23 ± 2.4 minutes for Ropivacaine with Dexmedetomidine group. Mean Highest pain score on VAS was 4.9 ± 0.8 for only Ropivacaine group and 3.8 ± 0.66 for Ropivacaine with Dexmedetomidine group. Number of Diclofenac injections in first 24 hrs postoperatively was 3.73 ± 0.64 for only Ropivacaine group and 1 ± 0.59 for Ropivacaine with Dexmedetomidine group. Blood pressure and Heart rate were significantly lower in Ropivacaine with Dexmedetomidine group compared to only Ropivacaine group.
Conclusion: Dexmedetomidine (5 μg ) as an adjunct to Ropivacaine is superior to Ropivacaine alone in intrathecal analgesia .It augments onset of action , prolongs sensory blockade and reduces requirement rescue analgesics. Its hemodynamic side effects can be treated with vasopressors.
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