Dexmedetomidine and clonidine as an adjuvant to epidural anaesthesia: A prospective randomized, double blind study of their effect on postoperative sensory and motor block characteristics.

Background: Many researchers have been done to find an ideal adjuvant to ropivacaine in regional anaesthesia that inhibits intra and post-operative pain and prolong the duration of anaesthesia without any side effects. Aim: This study was conducted to evaluate the onset, extent and duration of sensory and motor block and side effects of clonidine or dexmedetomidine when used as an adjuvant to ropivacaine in epidural anaesthesia in lower limb orthopaedic surgery. Methods: A prospective randomized study was conducted on 60 patients of American society of anaesthesiologists’ status I and II, posted for lower limb orthopaedic surgery. All patients were randomly allocated into two groups of 30 each; group I was ropivacaine - clonidine group (RC) and group II was ropivacaine - dexmedetomidine group (RD). Group I (RC) patients received 16 ml of 0.75% ropivacaine and clonidine 2 mcg/kg. Group II (RD) patients received 16 ml of 0.75% ropivacaine and dexmedetomidine 1.5 mcg/kg. The onset, extent, duration of sensory and motor blocks, and side effects were recorded. Results: Dexmedetomidine had a visible edge over clonidine as it enabled an earlier onset and longer duration of sensory and motor block. Sedation scores were statistically significant with the RD group in comparison to RC group. The RD group showed visible superiority over the RC group in various post-operative block characteristics like the weaning of sensory and motor block, prolonged post-operative analgesia. Conclusion: Dexmedetomidine was a better alternative to clonidine as an adjuvant to ropivacaine in epidural anaesthesia in orthopaedic lower limb surgeries.

The Effects of Two Different Doses of Clonidine as Adjuvant to Ropivacaine in Supraclavicular Brachial Plexus Block- A Randomized Controlled Study.

Background: Several clinical studies have shown that clonidine prolongs sensory motor blockade when used with bupivacaine but ideal doses of clonidine on ropivacaine is not well defined and to evaluate the effect of two doses of clonidine on ropivacaine, for supraclavicular brachial plexus blockade. Methods: In a prospective randomized double blind study supraclavicular brachial plexus blockade were performed in 80 patients using 35 ml ropivacaine (0.5%). Group A (n=40) had 2 μg/kg clonidine and in Group B (n=40) 1 μg/kg clonidine added to ropivacaine. Sensory and motor blockade was assessed every 5 min till 30 min and at 15 min interval thereafter. Results: Mean sensory onset time in group A was 10.42 ± 5.5 min and in group B was 15.83 ± 6.51 min, which was statistically significant. Patients of group A had a mean motor onset time 14.35 ± 7.8 min and patients of group B had a mean motor onset time 18.53 ± 7.61 min, the difference being statistically significant. Mean duration of sensory block in group A was 484.13 ± 63.1 min and in group B was 390.83 ± 72.63 min, which was statistically significant. Patients in-group A had a mean duration of motor block 550 +60.1 min and patients in group B had a mean duration of motor block 430.43+68.5 min, which was statistically significant. Conclusion: The addition of clonidine in dose of 2 μg/kg to ropivacaine for brachial plexus blockade, increases the onset and duration of motor and sensory block significantly.