Fentanyl as an adjuvant for brachial plexus block: a randomized comparative study

Background: Adjuvants are known to enhance the effect of local anaesthetics (LA). Several adjuvants have been suggested to enhance the duration and analgesic effect of local anesthetic agents. We designed this randomized single blinded prospective study to compare the analgesic efficacy of Fentanyl used as an adjuvant to ropivacaine for supraclavicular brachial plexus block in patients undergoing orthopaedic surgeries of forearm. Methods: For this randomised prospective, single blinded study 66 ASA I and II patients aged 18-65 years were included and were divided into 2 groups, group R (35) and RF (31). Supraclavicular brachial plexus block was performed in the group R using 0.5% ropivacaine 30 ml  plus 1 ml NS (total 31 ml) and in group RF received 0.5% ropivacaine plus 50 micrograms fentanyl in 1 ml NS (total 31 ml) in brachial plexus block. The onset time of sensory and motor block, duration of sensory and motor block were recorded. Results: Compared to group R, group RF showed a significant greater duration of sensory and motor blockade (?=0.0001). Demographic parameters and block onset time were comparable in both the groups. Conclusions: The addition of fentanyl to ropivacaine significantly prolonged the duration of analgesia compared to ropivacaine used alone for supraclavicular brachial plexus blocks in patients undergoing forearm surgeries.