The Interfascial Plane Block: An Adjunctive Ultrasound-Guided Block for Proximal Humerus Fracture and Fracture Dislocation Anesthesia and Analgesia in the Emergency Department

BACKGROUND: Proximal humerus fractures (PHFs) and fracture-dislocations (PHFDs) are frequently encountered in the emergency department (ED). Adequate pain control for these injuries can be challenging, and traditional methods, including opioid analgesics and other blocks may pose significant risks such as medication side-effects and hemidiaphragmatic paresis. The interfascial plane block (IPB) is an emerging, ultrasound-guided technique that targets the fascial plane between the deltoid and subscapularis muscles, potentially offering safer and more focused analgesia for acute shoulder injuries.

CASE REPORT: We present two cases of acute traumatic shoulder injuries-a proximal humerus fracture and a proximal humerus fracture-dislocation-managed successfully with the IPB in the ED. Both patients achieved significant pain relief within 15 minutes of receiving 20 mL of 7.5 mg/mL ropivacaine, facilitating immobilization in one case and closed reduction in the other without additional sedation. This technique carries several advantages for ED practice, including reduced risk of diaphragmatic compromise compared to interscalene blocks (ISBs) and a lower likelihood of motor blockade. Furthermore, the IPB is relatively easy to learn, particularly for clinicians already accustomed to ultrasound-guided regional anesthesia techniques. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Given its rapid onset, simplicity, and favorable safety profile, the IPB presents a valuable addition to the repertoire of regional anesthesia techniques in the ED. It can reduce reliance on systemic opioids, enhance patient comfort, and potentially expedite crucial interventions such as fracture reduction-all of which are vital for optimal patient care in a busy acute care setting.