The infraclavicular nerve block, which is frequently preferred in upper extremity surgeries, provides additional advantages such as reduction in opioid consumption by providing analgesic effect in the postoperative period as welll. The success of peripheral nerve blocks is usually assessed by subjective feedback from the patient, and patient cooperation is needed. The aim of this study is to assess whether the perfusion index level, which can be measured noninvasively, can be a predictor of the infraclavicular block success.

Thirty patients who were operated on for carpal tunnel syndrome under infraclavicular brachial plexus block were included in our study. After the procedure, at 10-minute intervals, the sensory block was assessed by a pinprick test, and the motor block was assessed by the ability to flex the hand and the forearm. In addition, PI and skin temperature were measured 0-10-20-30 minutes after the block and at postoperative 2, 4, and 6 hours. 30 minutes after the measurements, the surgical procedure was allowed to begin in patients with successful block.

Inclusion Criteria:

• Ages of 18-75
• Patients who will diagnose with carpal tunnel syndrome by electroneuromyography (ENMG), and will undergo unilateral surgery under elective conditions
• ASA I-II-III patients

Exclusion Criteria:

• Patients who will refuse this method
• Neurological deficits,
• Diabetes mellitus,
• Local anesthetic allergy,
• Morbidly obese,
• Peripheral vascular disease, coronary artery disease, or coagulopathy