Research progress on brachial plexus block techniques for preserving diaphragmatic function in shoulder surgery

Shoulder surgeries, including shoulder arthroscopy, open reduction and internal fixation(ORIF)for clavicular fractures and proximal humeral fractures, are common orthopedic procedures. Severe postoperative pain frequently occurs following these surgeries due to intraoperative electrocautery, continuous intra-articular irrigation and other operative factors. Ultrasound-guided brachial plexus block can effectively reduce surgical stress responses, provide satisfactory postoperative analgesia and facilitate early functional rehabilitation. It can also achieve sufficient surgical anesthesia and avoid tracheal intubation under general anesthesia, thereby significantly reducing perioperative anesthetic risks for high-risk patients. However, hemidiaphragmatic paralysis(HDP), the most prevalent adverse effect of brachial plexus block, limits its clinical application in patients with preexisting respiratory insufficiency, such as those with morbid obesity and neuromuscular diseases. Notably, patients with respiratory dysfunction are often the population who benefit the most from nerve block anesthesia. Accordingly, numerous studies have focused on brachial plexus block techniques with diaphragmatic function preservation. This review summarizes the research progress of these modified block techniques, so as to provide a reference for their clinical application.