Rethinking shoulder analgesia: The SHAC block technique and utilization in the emergency department

There are a marked number of Emergency Department (ED) patients with shoulder pain and pathologies including shoulder dislocation and proximal humeral fractures that benefit from nerve blocks. Further, there is a significant interest in nerve blocks that are low-risk and pose no risk of phrenic nerve paralysis. There was a recent nerve block developed in anesthesia and cadaveric studies, called the SHoulder Anterior Capsule Block (SHAC Block). The thought, compared to an interfascial plane block alone (injecting in between deltoid and subscapularis), by also injecting anesthetic deep to subscapularis, there would be more reliable coverage beyond the axillary nerve distribution. This technique was employed in the ED; to our knowledge, this is the first case series exploring the applications of its use in the ED. There were three patients that received a SHAC block (two proximal humerus and one shoulder dislocation); these all had successful pain management without any complications. The patient with an anterior shoulder dislocation underwent reduction without sedation and in minimal pain. This highlights the potential of this block in the ED, and also poses the potential of future research of this block, including studies comparing the efficacy of the SHAC to alternative blocks.