Pulse Wave Transit Time After Infraclavicular Block

This prospective observational study aims to evaluate the time-dependent changes in Pulse Wave Transit Time (PWTT) following ultrasound-guided infraclavicular brachial plexus block. PWTT is a non-invasive hemodynamic parameter reflecting vascular tone and sympathetic nervous system activity. Patients undergoing upper extremity surgery under infraclavicular block will be monitored using standard perioperative monitoring devices. PWTT measurements will be obtained before and after block placement at predefined time intervals. Secondary outcomes will include perfusion index, skin temperature, heart rate, blood pressure, respiratory rate, and oxygen saturation. The study seeks to determine whether PWTT can serve as an objective and non-invasive marker of sympathetic blockade following infraclavicular block.

Inclusion Criteria: * Patients undergoing elective upper extremity hand surgery * 18 - 65 years * ASA I * No coagulopathy, thrombocytopenia, coagulation disorders * Patients who provide informed consent to participate in the study Exclusion Criteria: * History of drug allergy relevant to study procedures or local anesthetics * Body mass index (BMI) ≥ 30 kg/m² * Body weight \< 40 kg * Age \< 18 years or \> 65 years * History of significant cardiac disease (e.g., arrhythmia, conduction abnormalities) * Coagulopathy (INR \> 1.5 or platelet count \< 100,000/mm³) * Pregnancy or lactation * Infection at the site of peripheral nerve block * ASA II-IV * Failed block or motor block duration exceeding 30 minutes * Patients reporting pain (NRS ≥ 3), due to potential influence on sympathetic activity * Chronic opioid use