Fascial plane approach to anesthetizing the radial, median, and ulnar nerves: an educational review

Brachial plexus block provides effective anesthesia and analgesia for upper extremity surgery but requires injection of large anesthetic volumes near major vascular structures. Moreover, the extensive motor and sensory loss produced by plexus block often exceeds the neural distribution needed for corresponding surgical procedures.High-resolution ultrasound facilitates selective nerve blocks at nearly every level of the upper extremity. We present fascial plane injection techniques for selective radial, median, and ulnar nerve blocks. These techniques can be used to match sensory distribution with specific surgical procedures. They are performed using low anesthetic volumes and without proximity to nerves or vascular structures. In this article, fresh cadaver dissections with corresponding ultrasound images are used to demonstrate stepwise fascial plane techniques for the radial, median, and ulnar nerves. These techniques are performed using familiar anatomic landmarks.Practical applications of these techniques are demonstrated for commonly performed procedures of the upper extremity. Corresponding injection volumes with duration of postoperative analgesia are presented. Selected injections are described for both surgical anesthesia and postoperative analgesia.Selective fascial plane injections can provide surgical anesthesia and postoperative analgesia in settings that might otherwise require much larger volumes of local anesthetic. These selective nerve blocks can match sensory loss with the anatomic pain distribution in each patient. Reliable techniques for selective nerve blocks of the upper extremity can expand the capabilities for ultrasound-guided regional anesthesia.