Nerve conduction studies in regional intravenous analgesia using 1 per cent lignocaine.

The effects of regional intravenous analgesia in the upper limb were studied in eight subjects by means of clinical examination and serial nerve conduction techniques. The changes following 1 per cent lignocaine analgesia and ischaemia were compared with those following ischaemia alone; the latter produced analgesia and impairment of conduction at a considerably slower rate than it did when combined with 1 per cent lignocaine. It was found that 1 per cent lignocaine caused a block in conduction of the nerve trunks at the site of maximal concentration of drug in the limb. The proximal site of blockade may be of value in practice when the peripheral sensory nerve endings in the region of the operative site cannot be perfused adequately.