Ultrasound-guided continuous infraclavicular brachial plexus block using bupivacaine alone or combined with adenosine for pain control in upper limb surgery

INTRODUCTION: The infraclavicular brachial plexus block (ICB) is designed to deposit anesthetic high in the plexus, achieving anesthesia of the hand, forearm, elbow, and distal arm. Adenosine is a metabolic intermediate that is involved in nearly all aspects of cell function, including neurotransmission and signal transduction.This study was aimed to show whether addition of adenosine to bupivacaine in ultrasound-guided ICB had an analgesic effect. METHODS: Sixty adult patients were divided into two equal groups, each group included 30 patients. Group I received infraclavicular bupivacaine 0.325% in a volume of 30 ml. Group II received 30 ml of 0.325% bupivacaine + 12 mg adenosine. The block was maintained with an infusion of 10 ml/h. The following parameters were assessed: Success rate, time of the sensory onset, motor block, visual analog scale (VAS), and amount of i.v. pethidine needed. RESULTS: This study showed an analgesic effect of infraclavicular adenosine as evidenced by a statistically significant shorter mean time of onset of the sensory block (16 vs. 20 min, P < 0.05), lower mean VAS score over 48 h (1.7 vs. 2.7, P < 0.05), longer mean time of first parenteral analgesic requirement (299 vs. 255 min, P < 0.05), and lower mean total dose of pethidine needed over 48 h after surgery (25.5 vs. 56.6 mg, P <0.05). All patients got successful infraclavicular block and recovered uneventfully without any sensory or motor deficit. CONCLUSION: Adenosine may provide valuable addition to the therapeutic options in anesthesia and pain management. Further research is required to figure out its exact role