Comparative evaluation of ultrasound-guided supraclavicular approach and subclavian perivascular approach to brachial plexus block for upper-limb surgeries: A prospective randomised control study

Background: Subclavian perivascular block aims to anaesthetise three trunks of the brachial plexus at its most compact point. Hence, a low dose of local anaesthesia is sufficient. Methods: The prospective randomised study consisted of 60 adult patients belonging to American Society of Anaesthesiologists (ASA) classification Grade I and II, scheduled for upper-limb surgeries, who were randomised to Group A (US-guided supraclavicular block) and Group B (US-guided subclavian perivascular block). Blocks were performed with a 20 mL equal mixture of 2% lignocaine + adrenaline and 0.5% bupivacaine. Sensory and motor blockades were assessed using a needle prick method and four-point scale, respectively; blockade was evaluated every 3 min till onset and then every 30 min after surgery. Eventually, inference was made in terms of block performance time, onsets and duration of sensory and motor blocks and first rescue analgesia. Results: The mean age, body mass index, gender and ASA grades of the patients in both the groups were comparable. The block performance time was significantly shorter in Group B (12.3 ± 1.53) compared to Group A (21.90 ± 2.47; P < 0.0001). The complete blockade time for sensory and motor blocks was significantly shorter in Group B compared to Group A (P < 0.0001), whereas no significant difference was found with respect to first rescue analgesia (P = 0.9688). Conclusions: US-guided subclavian perivascular block is more rapidly executed than US-guided supraclavicular block with a similar duration of blockade.