Sympatholytic Effects of High Thoracic Erector Spinae Plane Block: Changes in Optic Nerve Sheath Diameter

The thoracic erector spinae plane (ESP) block is a regional anesthesia technique used for pain management in complex regional pain syndrome. This procedure involves injecting 20 ml of 0.25% bupivacaine into the deep layers of the erector spinae muscles. The patient is positioned appropriately, and the injection site is identified using anatomical landmarks and ultrasound guidance, at the T2 level. A needle is then inserted perpendicularly until it contacts the transverse process, at which point the local anesthetic is administered. The primary objective is to provide significant pain relief.