Is Paravertebral-Epidural Spread the Underlying Mechanism of Action of Erector Spinae Plane Block?

Abstract

Erector spinae plane block (ESPB) is an ultrasound (US)-guided regional anaesthesia technique. The proposed mechanism of action of ESPB is local anaesthetic spread in a cephalocaudal direction within the fascial plane deep to the erector spinae muscle (ESM) in paraspinal region and towards paravertebral space through inter-transverse soft tissue (1, 2). It remains unclear how the block provides somatic and visceral blockade (3).