Clinical Research Directory

Inclusion Criteria: * Adults aged 18 to N/A (no limit) * Scheduled for elective lumbar spine surgery (e.g., decompression or fusion) via posterior approach * American Society of Anesthesiologists (ASA) physical status I-III * Body weight ≥ 50 kg * Ability to provide written informed consent * Expected postoperative hospitalization of at least 48 hours Exclusion Criteria: * Known allergy or contraindication to ropivacaine, dexamethasone, or dexmedetomidine * Infection at or near the site of block placement * Coagulation disorders or current use of anticoagulant therapy (not discontinued per guidelines) * Chronic opioid use or opioid dependence * Neurological or psychiatric disorders interfering with pain assessment * Diabetes mellitus with poorly controlled glycemia (e.g., HbA1c \> 8%) * Severe hepatic or renal dysfunction * Body mass index (BMI) \> 40 kg/m² * Pregnancy or breastfeeding * Refusal or inability to cooperate with the study protocol