Basic UGRA can be performed only with ultrasound without supplemental electrical nerve stimulation (ENS) technique.
Advanced and expert UGRA require 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ENS is obsolete for most blocks for the purpose of nerve localisation.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.
