The perfusion index (PI) measured in brachial plexus blocks with ultrasonography; Investigation of correlation with block success

Objective: Brachial plexus block is one of the peripheral nerve blocks commonly used in regional anesthesia. Peripheral nerve blocks provide more advantageous conditions in cases where general anesthesia or spinal anesthesia is risky, such as heart, kidney, respiratory system diseases, chest trauma and diabetic patients. Successful peripheral nerve blockage; local vasodilatation, increased local blood flow, a slight increase in skin temperature and loss of sensation in the extremities due to blockage of sympathetic fibers. However, in an intense and cold operating room environment, these clinical findings may not appear quickly enough to confirm block adequacy before or during surgery, and may not be used for clinical decision making, which also requires patient collaboration. In our study; we aimed to investigate whether perfusion index (PI) measurement can be used as a reliable and objective method to evaluate the adequacy of upper extremity blocks. Method: Thirty three ASA I-II patients aged 18-65 years were included in the study. Brachial plexus block of the appropriate type was applied to these patients. After the completion of the block application sensory and motor block 20 minutes within 5, 10 and 20 minutes. Peripheral oxygen saturation (SpO2), heart rate (HR), noninvasive arterial pressure (NAB) and perfusion index (PI) measured from both extremities were recorded at 5, 10 and 20. minutes. Findings: In 32 of 33 patients with brachial plexus block, our block was successful and perfusion index (PI) measurements in the blocked extremity increased continuously from the 5th minute on during the 20 minutes observation period. In one patient with block failure and in the arm group without block; no statistically significant difference was found in the perfusion index (PI) measurements at 5, 10 and 20th min. Conclusion: Perfusion index (PI) measurement; it is a valuable and useful method for early, easy and objective evaluation of the success of peripheral nerve blocks. Keywords: Peripheral nerve block, brachial plexus block, axillary block, infraclavicular block, supraclavicular block, perfusion index.