Clonidine as an adjuvant to local anesthetic in supraclavicular brachial plexus block: a randomized, double blinded placebo controlled study

Background: Many drugs have been studied as adjuvants to local anesthetic agents with the aim of improving the quality of anesthesia and to provide profound analgesia. Clonidine has also been used as an adjunct to local anesthetic agents in various regional techniques. The studies regarding clonidine in brachial plexus block have given mixed results. Aim was to determine whether addition of clonidine to the local anesthetic solution for brachial plexus block by supraclavicular approach, prolongs sensory and motor blockade and improves postoperative analgesia. Also to observe side effects if any.Methods: 60 patients aged 18-60 years, were randomly allocated into two groups. Group A received 2 µg / kg of Clonidine diluted to 1 ml with saline and group B received 1 ml of saline added to bupivacaine (10 ml 0.5%) and lignocaine (20 ml 2 %) solution, in the supraclavicular block. The onset and duration of sensory and motor block was compared along with the duration of analgesia, sedation in both the groups. Patients’ pulse rate, blood pressure, saturation was also recorded.Results: Addition of clonidine had no effect on the onset of the block, but was found to increase the duration of sensory and motor block along with the increase in the duration of analgesia. Visual analogue score for pain was significantly lower in the group receiving clonidine.Conclusions: Clonidine 2 µg / kg added to 10 ml of 0.5 % Bupivacaine + 20 ml of 2% lignocaine with adrenaline (1:200000) is a good option for improving the quality and duration of supraclavicular brachial plexus block