Comparison of Interscalene Brachial Plexus, Anterior Suprascapular Nerve, and Costoclavicular Brachial Plexus Blocks in Arthroscopic Shoulder Surgery: A Prospective Observational Study

<b>Background:</b> Interscalene brachial plexus block (ISB) remains the gold standard anesthesia method in shoulder surgery. However, risk of diaphragm paralysis is a major concern among anesthesiologists. Recent studies on anterior suprascapular nerve block (ASB) and costoclavicular brachial plexus block (CCB) have given promising results for preventing diaphragm paralysis and providing sufficient analgesia. <b>Methods:</b> Forty-six patients who underwent arthroscopic shoulder surgery under one of three regional anesthesia techniques, including ISB (<i>n</i> = 15), ASB (<i>n</i> = 15), and CCB (<i>n</i> = 16), were included in the study. Diaphragmatic excursion was measured by ultrasonography 30 min after the block. Postoperative pain was assessed with a numerical rating scale. The groups were compared in terms of diaphragm paralysis and postoperative pain status. <b>Results:</b> The groups were similar in basic patient and surgical characteristics as well as motor and sensory block scores. There was no difference in analgesic use between the groups. Diaphragm measurements in the ISB group were found to be significantly lower compared to the ASB and CCB groups (<i>p</i> < 0.001). In addition, diaphragm measurements in the ASB group were found to be lower than in the CCB group (<i>p</i> = 0.036). When comparing diaphragm measurements between the initial and 30th min of block, significant decreases were observed in the ISB and ASB groups (<i>p</i> < 0.001), whereas no difference was found in the CCB group. <b>Conclusions:</b> Postoperative pain scores and analgesic use were similar between the three blocks. In terms of diaphragm paralysis, the best blocks appeared to be CCB followed by ASB. CCB and ASB can be considered as safe and effective alternative blocks in arthroscopic shoulder surgery, particularly for patients without serious obstructive or restrictive pulmonary disease.