Supraclavicular brachial plexus block using a nerve stimulator and an insulated needle

A technique employing a nerve stimulator and an insulated needle was used for supraclavicular brachial plexus block in 71 patients using 0.5% plain bupivacaine 15-20 ml. The mean minimal stimulating current to produce paraesthesia was 0.09 mA. The plexus was identified at a mean depth of 27 mm below the skin. The block was successful in 98% of patients when the stimulation was felt in the index, middle or ring finger, but was often incomplete when felt in the thumb or little finger.