RESUMO
PURPOSE: The relationship between near-infrared spectroscopy cerebral oximetry (CrSO2), peripheral oximetry (PrSO2) and hemodynamic variables is not fully understood. METHODS: The relationship between CrSO2/PrSO2 and cardiac index (CI), systemic vascular resistance index (SVRI) and mean arterial pressure (MAP) in patients experiencing cardiogenic shock and those undergoing venoarterial extracorporeal membrane oxygenation (ECMO) was retrospectively analyzed; in patients on ECMO, total circulatory index (TCI) was calculated from the sum of CI and extracorporeal blood flow index. RESULTS: In patients experiencing cardiogenic shock (n=10), significant correlations between PrSO2 values and CI (Spearman r=0.81; P<.0001), SVRI (r=-0.45; P<.0001), and MAP (r=0.58; P<.0001) were found. Significant correlations between CrSO2 and CI (r=0.55; P<.0001) and SVRI (r=-0.47; P<.0001), but not MAP, were observed. Linear regression analysis revealed that CI could be calculated using the following equation: CI=PrSO2/24.0. In patients on VA ECMO (n=12), significant correlations were found between PrSO2 and TCI (r=0.68; P<.0001), SVRI (r=-0.47; P<.0001), and MAP (r=0.27; P=.025). Significant correlations were also found between CrSO2 and TCI (r=0.68; P<.0001) and SVRI (r=-0.51; P<.0001), but not MAP. CONCLUSIONS: Results of the present study suggest that CrSO2 and PrSO2 in particular can be used for noninvasive estimation and monitoring of global circulatory status in patients experiencing cardiogenic shock and individuals undergoing ECMO.
