Nerve Blocks at the Wrist for Carpal Tunnel Release Revisited: The Use of Sensory-Nerve and Motor-Nerve Stimulation Techniques

Abstract

This study describes how infrequently an initial motor response is identified when a nerve stimulator is used on the median nerve at the wrist. A very high success rate of median and ulnar nerve block at the wrist is obtained by use of sensory or sensory-motor-nerve stimulation and less than 10 mL of anesthetic solution.

Minimal Local Anesthetic Volume for Peripheral Nerve Block

“…7Y9, 16,17 Casati et al 18 used 15 mL LA for femoral nerve block using a single-injection technique to achieve a 50% success rate. By using a multi-injection technique, the same authors could slightly reduce the volume of LA for the same nerve block to 14 mL.…”

Outpatient Regional Anesthesia For Upper Extremity Surgery Update (2005 to Present) Distal to Shoulder

“…For instance, an example of such a scenario is the performance of carpal tunnel surgery under elbow or wrist blocks. 46,47 Ultrasound guidance allows for visualization of ulnar, median, and radial nerves from the elbow to the wrist. 48 The only randomized controlled trial evaluating whether ultrasound or nerve stimulation is superior for wrist block performance in patients undergoing carpal tunnel surgery did not reveal any differences in success rate, but showed a shorter block performance time in the ultrasound group, whereas the nerve stimulation group had a faster onset time of complete sensory block.…”

An objective assessment of nerve stimulators used for peripheral nerve blockade*

“…However, Aβ fibres, as found in some afferent nerves supplying skin receptors, have conduction velocities close to those of motor fibres. This could explain how low intensities applied for short durations during the final search for a nerve are able to elicit pulse‐synchronous paresthaesias when using the nerve stimulator [21].…”