Objective: To validate thenar oxygen saturation (StO2) measured by near-infrared spectroscopy (NIRS) as a noninvasive estimation of central venous saturation (ScvO2) in septic patients. Design: Prospective observational study. Setting: A 26-bed medical-surgical intensive care unit at a university-affiliated hospital. Patients: Patients consecutively admitted to the ICU in the early phase of severe sepsis and septic shock, after normalization of blood pressure with fluids and/or vasoactive drugs. Measurements: We recorded demographic data, severity score, hemodynamic data, and blood lactate, as well as ScvO2, and StO2 measured simultaneously on inclusion. Patients were divided into two groups according to ScvO2 values: group A, with ScvO2 < 70%, and group B, with ScvO2 ≥ 70%. Results: Forty patients were studied. StO 2 was significantly lower in group A than in group B (74.7 ± 13.0 vs. 83.3 ± 6.2, P 0.018). No differences in age, severity score, hemodynamics, vasoactive drugs, or lactate were found between groups. Simultaneously measured ScvO2 and StO2 showed a significant Pearson correlation (r = 0.39, P 0.017). For a StO2 value of 75%, sensitivity was 0.44, specificity 0.93, positive predictive value 0.92, and negative predictive value 0.52 for detecting ScvO2 values lower than 70%. Conclusions: StO2 correlates with ScvO2 in normotensive patients with severe sepsis or septic shock. We propose a StO 2 cut-off value of 75% as a specific, rapid, noninvasive first step for detecting patients with low ScvO2 values. Further studies are necessary to analyze the role of noninvasive StO2 measurement in future resuscitation algorithms. © 2009 Springer-Verlag.
- Near-infrared spectroscopy
- Tissue oxygenation