Body Mass Index and Outcomes of Ultrasound-Guided Infraclavicular Brachial Plexus Block

This study aims to investigate whether body mass index (BMI) is associated with differences in the time needed to perform an ultrasound-guided infraclavicular nerve block and how well the block works. This type of regional anesthesia involves injecting a local anesthetic near the nerves below the collarbone to numb the arm for surgery. The study will include 100 adults undergoing planned hand, wrist, or forearm surgery at Ankara Bilkent City Hospital. Researchers will compare 50 participants with a BMI below 30 kg/m² and 50 participants with a BMI of 30 kg/m² or higher. The study will assess the time needed to perform the block, block success, the time until sensation and movement are blocked, and patient satisfaction. Researchers will also examine whether arm circumference and muscle measurements are associated with block outcomes. This is an observational study. Participants will receive routine anesthesia and surgical care, and their treatment will not be assigned or changed for research purposes.

Inclusion Criteria: * Age 18 years or older. * American Society of Anesthesiologists (ASA) physical status I, II, or III. * Scheduled for elective hand, wrist, or forearm surgery under ultrasound-guided infraclavicular brachial plexus block. * Willing to receive regional anesthesia. * Willing and able to provide written informed consent. Exclusion Criteria: * Known allergy to local anesthetic agents. * Infection at the planned injection site. * Anatomical deformity at the planned block site. * Coagulopathy or active bleeding diathesis. * Severe peripheral neuropathy. * Pregnancy or breastfeeding. * Inability to cooperate with study assessments because of cognitive or mental impairment.