Real-time view of anesthetic solution spread during an ultrasound-guided thoracic paravertebral block

Thoracic paravertebral block is a technique for perioperative analgesia in patients undergoing thoracic, chest wall, or breast surgery, or for pain management with rib fractures, which can be performed with or without ultrasound guidance. The ultrasound guidance technique can be used to identify the thoracic paravertebral space, guide needle placement, monitor the spread of local anesthetic (LA) solution, and reduce complications such as pleural puncture and pneumothorax. The possibility of assessing anesthetic spread in real time using ultrasound guidance during paravertebral block offers numerous advantages, including the immediate and accurate identification of the extent of nervous block, with a consequent reduction of LA dose. The real-time visualization of spread may be used to achieve good anesthetic cover by administering the block at a single level, thus reducing complications normally associated with the technique.

This case report describes the use of ultrasound-guided thoracic paravertebral block, at thoracic (T) 4 and 5 levels, in a patient undergoing breast surgery for perioperative analgesia. The authors were able to witness cranial diffusion of LA at T3-T4 in real time, and measure the increase in space between the costotransverse ligament and pleura, as an indication of anesthetic spread, at T2-T3 and T6-T7 levels.

This is the first known case in the literature of direct viewing of LA diffusion in a paravertebral space other than the one in which the block is administered and may open important scenarios for the improvement of anesthesia technique.