Block characteristics of Dexmedetomidine as an adjuvant to local anaesthetic in Infraclavicular brachial plexus block using peripheral nerve stimulator and ultrasound

Introduction: Dexmedetomidine has been frequently used in regional anaesthesia to improve the quality of blocks. Addition of dexmedetomidine to local anaesthetics has been shown to hasten the onset of both sensory and motor blocks and also prolong the duration of analgesia. The objective of this prospective comparative study was to assess the change in characteristics of infraclavicular brachial plexus block after adding Inj. Dexmedetomidine to 2% Lignocaine with Adrenaline. Methods: Sixty-six patients, scheduled for upper limb surgeries under ultrasound guided infraclavicular brachial plexus block were randomly allocated to two groups. Group LS received Inj. Lignocaine 2% with Adrenaline, 7mg/kg diluted to 30 ml with saline and Group LD received Inj. Dexmedetomidine 0.75 mcg/kg in addition to Inj. Lignocaine 2% with Adrenaline, 7mg/kg again diluted to a total volume of 30 ml. The parameters studied were: onset of sensory and motor blocks and duration of analgesia. Results: Sixty patients completed the study. The demographic variables and motor block were similar between both groups. The mean time to onset of sensory block was significantly faster in Group LD compared to Group LS (9.80±4.85 min vs 12.30±3.97 min, p=0.033). The duration of analgesia was also found to be prolonged in Group LD compared to Group LS (286.73±55.38 min vs 226.53±41.19 min, p < 0.001). Conclusion: Addition of 0.75 mcg/kg of Dexmedetomidine to 2% Lignocaine with Adrenaline hastens the onset of sensory block and prolongs the duration of analgesia in ultrasound guided and peripheral nerve stimulator guided infraclavicular block.

Comparison of the onset time between 0.375% ropivacaine and 0.25% levobupivacaine for ultrasound-guided infraclavicular brachial plexus block: a randomized-controlled trial

At centers with pressure on rapid operating room turnover, onset time is one of the important considerations for choosing a local anesthetic drug. To hasten the onset of the block, higher concentrations of local anesthetics are sometimes used. However, the use of diluted local anesthetics may be safer. Therefore, we aimed to compare the onset times of equipotential levobupivacaine and ropivacaine at low concentrations for infraclavicular brachial plexus block. Adult patients undergoing upper extremity surgery under ultrasound-guided infraclavicular brachial plexus block at our center were randomly allocated to the levobupivacaine and ropivacaine groups. Infraclavicular brachial plexus block was induced with 0.25% levobupivacaine or 0.375% ropivacaine depending on the assigned group. The degrees of sensory and motor blockade were assessed for 40 min after the administration of local anesthetics. A total of 46 patients were included in the analysis. Infraclavicular brachial plexus block with 0.25% levobupivacaine and 0.375% ropivacaine provided sufficient surgical anesthesia. The sensory onset time of 0.375% ropivacaine was shorter than that of 0.25% levobupivacaine (group R, 15 [15.0–22.5] min; group L, 30 [17.5–35.0] min, p = 0.001). There were no significant differences in other block characteristics and clinical outcomes between the two groups. Thus, when a quicker block onset is required, 0.375% ropivacaine is a better choice than 0.25% levobupivacaine.Trial registration ClinicalTrials.gov (NCT03679897).