Basic UGRA can be performed only with ultrasound without supplemental electrical nerve stimulation (ENS) technique
Advanced UGRA requires a combination of ultrasound and ENS for various blocks
ENS is obsolete for most blocks for the purpose of nerve localisation; however, sometimes peripheral nerves are not visible with ultrasound and ENS can be useful in order to confirm nerve identity
Generally, the main purpose of ENS is a safeguard in order to assist avoiding accidental piercing of peripheral nerves and intraneural injection
