[Brachial plexus block with a nerve stimulator and "around the needle" catheter technique]

Brachial plexus block using a nerve stimulator is an accurate procedure. But prolonged analgesic effect can not be obtained. Therefore we used "around the needle" catheter technique to have a long analgesic effect. A 20-gauge, 5-inch intravenous catheter (Angiocath) was threaded over a 23-gauge, 10-cm needle (Pole). We used axillary approach. The cathode of the nerve stimulator (NS-2CA, Professional Instrument company) is connected to the needle, and its anode is connected to the electrode on the surface of the skin. When the needle is introduced and advanced, 1 mA of electric current is applied for nerve stimulation. When the muscle twitch is obtained, a plastic cannula is then threaded off the needle into the axillary sheath. An infusion tube and three way stopcock is connected to the cannula. From 1988 to 1991 we had 31 cases. The success rate is about 90%. If we stimulate other nerves in the same sheath, it is not necessary to seek aimed one. But the musculocutaneous nerve is the only exception, because it may be stimulated outside the neurovascular sheath.