Effect of combined versus sequential injection of 2% lidocaine and 0.5% bupivacaine on the onset and duration of supraclavicular brachial plexus block: A double blinded randomised controlled trial

Abstract

ObjectiveTo assess whether sequential (one after the other with a delay of 120 s) or combined (freshly prepared mixture) administration of 2% lidocaine and 0.5% bupivacaine in supraclavicular brachial plexus block (SCBPB) provides faster onset and prolonged duration of block. DesignRandomised controlled double blinded study. SettingSingle centre study in an operating theatre of a tertiary care facility between November 2018 and May 2020. PatientsNinety-seven patients of either sex, aged between 18 and 65 years, belonging to ASA I to III and undergoing surgery suitable to be performed under SCBPB were enrolled. InterventionUltrasound guided SCBPB was performed with 20 mL of freshly prepared mixture of 2% lidocaine and 0.5% bupivacaine (10 mL each) in group C (combined) and 10 mL 2% lidocaine followed 120 s later by 10 mL 0.5% bupivacaine in group S (sequential). Main outcome measuresTime to onset of complete sensory block was the primary outcome while time to onset of first sensory block and complete motor block, duration of sensory and motor block, duration of analgesia, use of intraoperative supplement, rescue analgesic consumption, and pain scores at rest and with movement were secondary outcomes. Main resultsThere was no significant difference between group C and group S in time to onset of complete sensory block [median (IQR) 16 (11, 20.5) and 15.5 (13, 21.75) minutes respectively] (p-value 0.58). The time to onset of first sensory block and motor block, duration of sensory and motor block, duration of analgesia, use of intraoperative supplement, postoperative pain scores and rescue analgesic requirement were also similar (p-value >0.05). ConclusionThere was no advantage of sequential administration of 2% lidocaine and 0.5% bupivacaine over the administration of combination of both LAs in terms of onset and duration of block.