Background and Aims:Ropivacaine is a new amide, long acting, pure S-enantiomer, local anesthetic, with differential blocking effect. The addition of clonidine to local anesthetic improves the quality of peripheral nerve blocks. This study was conducted to evaluate the effect of clonidine on characteristics of ropivacaine-induced supraclavicular brachial plexus block.Material and Methods:A total of 60 adult patients were randomly recruited to two groups of 30 each: Group I: 30 ml 0.75% ropivacaine + 1 ml normal saline. Group II: 30 ml 0.75% ropivacaine + 1 mcg/kg clonidine diluted to 1 ml with normal saline.Results:The onset of sensorimotor block was earlier in Group II (4.36 ± 0.81 min for sensory block and 9.83 ± 1.12 min for motor block) than in Group I (4.84 ± 0.65 min for sensory block and 10.85 ± 0.79 min for motor block). The duration of both sensory and motor block were significantly prolonged by clonidine (P < 0.001). The duration of analgesia was also prolonged in patients receiving clonidine (613.10 ± 51.797 min vs. 878.33 ± 89.955 min). Although incidence of hypotension and bradycardia was higher in Group II when compared to Group I, it was not clinically significant.Conclusions:Ropivacaine 0.75% is well-tolerated and provides effective surgical anesthesia as well as relief of postoperative pain. Clonidine as an adjuvant to ropivacaine significantly enhances the quality of supraclavicular brachial plexus block by faster onset, prolonged duration of sensory and motor block and improved postoperative analgesia, without associated adverse effects at the dose used.

Background and Aims:Intravenous regional anaesthesia (IVRA) provides reliable and rapid analgesia with good muscular relaxation of the extremity distal to the tourniquet, but tourniquet pain and absence of post-operative analgesia are major drawbacks. α2 agonists, clonidine and dexmedetomidine are known to potentiate peripheral nerve blocks. The aim of this study was to compare clonidine and dexmedetomidine as adjuvants to IVRA with respect to block characteristics, tourniquet pain and post-operative analgesia.Methods:A prospective, randomised, double-blind study was conducted on 60 adult patients of American Society of Anesthesiologists physical status grades I and II, in two groups of 30 each, to receive either clonidine 1 μg/kg or dexmedetomidine 1 μg/kg added to 40 ml 0.5% preservative-free lignocaine. Independent samples t-test was used for analysing demographic data, haemodynamic data and block characteristics and Mann-Whitney U-test for skewed data.Results:Sensorimotor block onset was significantly faster and recovery delayed with dexmedetomidine as compared to clonidine. Intra-operative visual analogue scale (VAS) at 10 min, 15 min and 40 min and post-operative VAS at 30 min and 2 h were significantly higher with clonidine. Fentanyl consumption and sedation were comparable. Duration of analgesia was significantly longer with dexmedetomidine. Haemodynamic parameters were comparable.Conclusions:Dexmedetomidine significantly facilitates onset, prolongs recovery of sensory as well as motor block and also prolongs duration of analgesia as compared to clonidine.   Both decrease tourniquet pain satisfactorily and have comparable intra-operative fentanyl requirement . Patient satisfaction is better with dexmedetomidine.

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