Key points are not available for this paper at this time.
Introduction: Dexmedetomidine, an selective alpha-2 agonist, has been proposed as a safe and effective adjunct capable of extending the duration of a single-shot block. The present study aimed to investigate the efficacy of IV dexmedetomidine in improving the duration and quality of ultrasound guided brachial plexus block as compared to perineural use of dexmedetomidine as adjunct.Material and Methods: This was a randomized and double blind prospective study. 70 patients undergoing unilateral upper limb surgery under supraclavicular brachial plexus block were inducted. All the patients received 20 ml infusion of either the study drug or placebo as per group allocation over 20 minutes just prior to execution of brachial plexus block.Results: Mean duration of onset of sensory and motor block in both the groups were found to be similar (p=0.692). Both groups showed longer onset time for motor blockade as compared to onset time of sensory block. Perineural group showed significantly longer sensory & motor block as compared to DIV group. The time point for demand for first rescue analgesia, perineural group showed considerably longer duration of analgesia than group DIV.Conclusion: Dexmedetomidine (0.5 mcg/kg body weight) administered either perineurally or as IV bolus at the time of execution of brachial plexus block can considerably prolong both sensory and motor blockade duration without much influence on duration of onset of block. Perineural dexmedetomidine provides longer duration period of analgesia than intravenous route. But IV dexmedetomidine provides better intraoperative sedation and patient comfort as compared to equivalent perineural dose.
Bezbaruah et al. (Mon,) studied this question.