Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block for Analgesia in Arthroscopic Shoulder Surgery

Inclusion Criteria: * Classified as American Society of Anesthesiologists (ASA) physical status I-II-III * Scheduled for elective shoulder arthroscopy surgery * Surgery performed under general anesthesia * Provision of written informed consent Exclusion Criteria: * Use of anticoagulant or antiplatelet medications * Presence of bleeding diathesis or coagulation disorders * Known allergy or hypersensitivity to local anesthetics or opioid medications * Infection or history of previous surgery at the planned block site * Alcohol or drug dependence * Cognitive impairment preventing reliable pain assessment using the NRS * Pregnancy or lactation * Diabetes mellitus * Renal or hepatic impairment