Are the perfusion İndex and pleth variability index title an early İndicator of brachial plexus block?

Background: Studies on the evaluation of the Perfusion Index (PI) and the Pleth Variability Index (PVI) and the success of PI and PVI block in patients undergoing brachial plexus are limited and quite inadequate.

Aim: In our study, we aimed to compare PI and PVI between the interscalen block and infraclavicular block and evaluate its use as an early marker in block success.

Patients And Methods: Single-center prospective randomized controlled trials. Preoperative unit, operating room. Patients over 18 years of age who have had upper extremity surgery. Brachial plexus block (interscalene, infraclavicular). Demographic data, Hemodynamic parameters, Perfusion index and Pleth Variability Index. 40 patients, including ASA1-2, 20 patients over the age of 18, who were planned for upper extremity surgery, in the interscalen group, and 20 in the supraclavicular group, were included in the study. Demographic data of the patients were recorded by measuring PI and PVI values at baseline before the block and at the 1, 5, 10, 15, and 20 minutes after the block, both simultaneously.

Results: 62.5% (n = 25) of the patients included in the study were female. The mean age of the patients was detected as 52.63 ± 16.472, the mean BMI as 26.57 ± 4.423, and the mean entry hemoglobin level as 13.71 ± 1.87 g/dL. The hemodynamic data of the groups were similar across the time periods. The increase in PI increased significantly after 1 minute in both groups. The PVI was similar between the groups at all measurement times.

Conclusion: In our study, we observed an increase in PI from the 1 minute compared to the non-blocked arm in successful block applications. We consider the early indicator of PI in the evaluation of block success. In our study, we did not observe a significant change in the arm that was blocked and the arm that was not treated with PVI.