Comparison of Levobupivacaine 0.5% versus Ropivacaine 0.75% with Dexmedetomidine as an Adjuvant in Ultrasound-guided Supraclavicular Brachial Plexus Block: A Randomised Clinical Study

Introduction: Peripheral nerve blocks not only provide surgical anaesthesia but also minimise the stress response, in addition to providing postoperative analgesia. The addition of adjuvants augments the anaesthetic action of the drug and reduces the dose required, thus improving the safety margin. However, no single drug can be considered the optimum local anaesthetic or adjuvant at this time. In the quest to find a better local anaesthetic and adjuvant combination, dexmedetomidine has recently emerged as a promising adjuvant to local anaesthetics during regional anaesthesia procedures. Aim: To study the efficacy of levobupivacaine and ropivacaine with dexmedetomidine as an adjuvant using ultrasound in the Supraclavicular Brachial Plexus Block (SCPB). Materials and Methods: A randomised, double-blinded clinical study was conducted in the Department of Anaesthesiology, Jagjivan Ram Railway Hospital, Mumbai Central, Maharashtra, India from November 2019 to April 2021 on 60 adults aged 21-65 years with American Soceity of Anaesthesiology (ASA) class I and II, scheduled for upper limb surgery. Patients were randomised into two groups, each containing 30 patients. Group A received 20 mL of levobupivacaine 0.5% with 50 mcg of dexmedetomidine, while Group B received 20 mL of ropivacaine 0.75% with 50 mcg of dexmedetomidine. A comparison was made regarding the efficacy in terms of the onset of sensory and motor blockade, duration of sensory and motor blockade, haemodynamics, any adverse effects, and postoperative analgesia. Categorical covariates were compared using the Chi-square test, and continuous covariates were compared using the unpaired t-test. Results: The groups were comparable concerning demographic data and baseline haemodynamic parameters. There was no statistically significant difference when comparing the mean Heart Rate (HR), mean blood pressures, and mean oxygen saturations at different time intervals between the groups. The mean time±Standard Deviation (SD) for the onset of sensory block and motor block in the levobupivacaine group was 19.13±1.87 min and 29.53±2.86 min, respectively; this was statistically faster at 11.26±1.92 min and 7.53±1.35 min in the ropivacaine group (p-value <0.05). The mean duration of sensory and motor block in the levobupivacaine group was 459.83±26.40 min and 539.33±23.77 min, respectively, while it was longer at 878.66±17.46 min and 786.16±17.50 min in the ropivacaine group (p-value <0.05). Conclusion: The use of dexmedetomidine with ropivacaine for SCPB results in a quicker onset and longer anaesthetic effect compared to levobupivacaine. Dexmedetomidine should be utilised as an adjuvant to reduce anaesthesia induction time in SCPB.