Pericapsular Nerve Group Block vs Interscalene Block for Shoulder Arthroscopy

The diaphragmatic excursion will be measured in the supine position before the block and after surgery. A curvilinear US probe (5-7 MHz) will be placed at the subcostal area in the anterior axillary line, below the costal margin of the eighth and ninth ribs. The probe will be directed medially, cephalad, and dorsally to make the US beam reach the posterior third of the diaphragm perpendicularly. The probe will then be scanned along the long axis of the intercostal spaces, using the liver as the acoustic window on the right side and the spleen as on the left side. M-mode sampling line will be positioned perpendicularly to the diaphragm, and the diaphragmatic excursions could be measured during quiet and deep breathing.The measurement will be repeated three times, and the average value will be taken. After measurement of diaphragmatic excursion, patients will receive either a PENG block or an LV-ISBP block before induction of general anesthesia.