Background and Aim: Sub arachnoid block is most commonly used technique for lower limb surgeries. Various adjuvants are being used with local anesthesia for prolongation of intra operative and post-operative analgesia. Most of the clinical studies about intrathecal alpha-2 agonists are related to clonidine. In view of few evidences of Dexmedetomidine, efficacy as adjuvant to Ropivacaine in Spinal Anesthesia. This study was conducted to explore its usefulness and also to compare this new alpha-2 adrenergic agonist with the previously established and widely used adjuvants like Clonidine on spinal block characteristics and post-operative analgesia. This study meant to compare the effects of Dexmedetomidine 5 mcg versus Clonidine 15 mcg on blockade characteristics and postop analgesia when given as adjuvants to 0.75 % Ropivacaine. The objectives were to compare the onset and duration of sensory and the motor blockade, duration of analgesia, hemodynamic parameters and side effect profile in among two groups. Materials and Methods: 60 adult patients posted for lower limb surgeries were randomly allocated into two groups. Group D received 3 mL 0.75% ropivacaine with 5 mcg of Dexmedetomidine and group C received 3ml of Ropivacaine with 15 mcg of Clonidine. Patients were preloaded with 10mL/kg of Ringer’s lactate. Onset and duration of sensory and motor blockade, peak sensory level, 2 segment regression duration of analgesia and rescue analgesia requirement were noted and compared. Results: Patients in group D had earlier onset of sensory and motor block compared to group C. Mean time of onset of sensory block group D was 3.467±0.507 min and group C was 3.900±0.759 min with a p value of 0.012. Mean time for onset of motor block group D 9.033±1.098 min was group C 10.00±1.66 min with a p value of 0.010. Mean time for two segments regression in group D was 135.5±7.925 min and in group C was 125.567±5.27 min with a p value of 0.000. Duration of motor and sensory block were also significantly prolonged in group D compared to group C. Mean duration of motor block in group D was 339.367±27.031 min and in group C was 306.600±23.940 min with p value of 0.000. Mean duration of sensory block in group D was 421.133±21.968 min and in group C was 360.600±23.940 min with a p value of 0.000. Group D showed a significantly less requirement of analgesia than group C with a p value of 0.000. Hemodynamic were stable and comparable among both groups. Conclusion: We conclude that dexmedetomidine is a better adjuvant than clonidine in Spinal Anesthesia as far as patient comfort, stable cardio-respiratory parameters, intra-operative and post-operative analgesia is concerned. Overall the experience with Dexmedetomidine was quite satisfactory as compared to clonidine.
Varsha et al. (Fri,) studied this question.