Can ultrasound-guided regional anesthesia be improved with the combined use of nerve stimulation techniques?

Abstract

Currently, the most commonly used techniques to perform peripheral nerve blockade are ultrasound-guided regional anesthesia (UGRA) and nerve stimulation (NS). Since its introduction in the 1990s, the use of ultrasound has gained popularity. In the beginning, it was used together with NS to confirm identification of nerve structures, once the learning curve has reached its end, there is a trend to use UGRA alone. In this article, we discuss the pros and cons of performing RA procedures with NS, UGRA, or a combination of both, which we call stimulated and ultrasound-guided regional anesthesia (SUGRA). Even though the use of SUGRA does not seem to improve the success rate of the nerve blocks, does not shorten the time to perform them, and does not shorten the onset time, it does help to avoid intraneural injection without increasing patient's discomfort. The use of SUGRA with low-intensity current and without a generation of motor response, would allow positioning of the needle tip close to the nerve avoiding intraneural injection and nerve damage.