Recognition of local anesthetic maldistribution in axillary brachial plexus block guided by ultrasound and nerve stimulation ★

Nerve stimulation may occur despite the presence of a fascial barrier between the needle tip and the nerve, which may prevent appropriate flow or distribution of local anesthetic solution. During an axillary nerve block, ultrasound (US) guidance was used to identify the median nerve. Insertion of a needle with US and nerve stimulator guidance resulted in the appearance of the needle tip in contact with the nerve. However, as local anesthetic injection was begun, it was clear that the injectate was accumulating superficial to the investing fascia of the neurovascular bundle. No injectate was seen below the fascia. With US guidance, the needle was repositioned at a greater depth. Repeat injection of local anesthetic clearly flowed around the nerve.