Upper limb nerve blocks

Regional anaesthesia of the upper limb can be achieved by injecting local anaesthetic solutions into the brachial plexus according to many described techniques. The level at which injections are made into the neurovascular sheath will largely determine the block pattern. Terminal nerves of the brachial plexus can also be blocked further distal than the brachial plexus, either as a sole regional anaesthetic technique, or as a supplement to a brachial plexus block. The popular axillary approach has been the subject of a significant amount of research and it is now largely accepted that multiple-injection techniques provide more complete and reliable analgesia of the arm. A single injection into the plexus using median nerve stimulation often results in insufficient spread of the local anaesthetic to the retroarterial region. This could lead to incomplete anaesthesia because the radial nerve is not blocked. The musculocutaneous nerve also needs to be blocked separately. The advance of ultrasound-guided regional anaesthesia may improve the safety, success rate and ease of performance of some of the methods of brachial plexus block. It has helped the renewed interest in some of the less popular approaches to the brachial plexus, such as the infraclavicular block. However, further research is required to establish the definitive role of ultrasound in this area.