The effects of two different anesthesia techniques on peripheral regional tissue oxygenation, perfusion index, and brachial artery flow volume in the upper extremity

INTRODUCTION AND OBJECTIVE: In addition to general anesthesia (GA), the interscalene nerve block (ISB), either in combination with GA or used alone, are routine anesthesia methods for shoulder surgery. Both anesthesia choices are known to increase local blood flow. Our study aims to compare the effects of two different anesthesia techniques on forearm tissue oxygenation. METHODS: Our study included a total of 49 patients aged 18-65 who underwent shoulder surgery in our hospital between 15.12.2023 and 15.03.2024. After routine monitoring, a pulse oximeter was placed on the second finger of the side to be operated on, and an rSO2 sensor was attached to the forearm for perfusion index (PI) and regional oxygen saturation (rSO2) measurement. Measurements were performed using ultrasound (USG) by visualizing the brachial artery 2-3 cm proximal to the antecubital fossa. GA was administered to Group 1, and ISB to Group 2. Mean arterial pressure (MAP), heart rate (HR), SpO2, flow volume (FV), brachial artery diameter (BAD), near-infrared spectroscopy (NIRS) data (rSO2, ΔcHbi, Δo2Hbi, ΔHHbi), and PI values were recorded before the procedure and at 10, 20, 30, and 60 minutes after the block procedure was completed. RESULTS: In our study, statistically significant differences were observed in FV at 20, 30, and 60 minutes; rSO2 at 10, 20, 30, and 60 minutes; and Δo2Hbi at 30 and 60 minutes in patients who received GA and ISB. Significant increases in rSO2 and ΔcHbi were observed in the ISB group between 0/10 min, 0/20 min, 0/30 min, and 0/60 min. A significant increase in Δo2Hbi was found in the ISB group between 0/20 min, 0/30 min, and 0/60 min. PI values showed significant increases at 0/10 min, 0/20 min, 0/30 min, and 0/60 min in both groups. CONCLUSION: In our study, we believe that FV and rSO2 values will provide more significant data on forearm tissue perfusion and oxygenation. We think that the NIRS values (ΔcHbi, Δo2Hbi, ΔHHbi) used in measuring peripheral tissue oxygenation will guide future studies and that more research is needed.