Thoracic wall blocks: From paravertebral to retrolaminar to serratus to erector spinae and back again - A review of evidence.

A multitude of thoracic wall blocks have been described, including parasternal-intercostal plane, Pecs I and II, serratus anterior plane, paraspinal-intercostal plane, erector spinae plane blocks, and retrolaminar blocks. They are almost all fascial plane blocks, relying on passive spread of local anesthetic to target nerves within the plane or in adjacent tissue compartments. They have emerged as attractive alternatives to thoracic paravertebral and epidural blocks because of their relative simplicity and safety. Although research into these techniques is still at an early stage, the available evidence indicates that they are effective in reducing opioid requirements and improving the pain experience in a wide range of clinical settings. They are best employed as part of multimodal analgesia with other systemic analgesics, rather than as sole anesthetic techniques. Catheters may be beneficial in situations where moderate-to-severe pain is expected for >12 h, although the optimal dosing regimen requires further investigation.