Near-infrared spectroscopy during stagnant ischemia: a marker of ScvO₂–SvO₂ mismatch in septic patients with low cardiac output

Excerpt

Monitoring of oxygen saturation in the superior vena cava (ScvO₂) was suggested as a simpler and cheaper assessment of the global DO₂:VO₂ ratio and was used successfully as a goal in treatment of patients with septic shock and severe sepsis [1]. In patients with low cardiac output (CO) the difference between SvO₂ and ScvO₂ is more expressed and problematically large confidence limits and poor correlation were found between the two values [2]. The thenar muscle oxygen saturation (StO₂) measured with near-infrared spectroscopy (NIRS) during stagnant ischemia (cuff inflation-induced vascular occlusion) decreases slower in septic shock patients [3]. This may be due to slower muscle tissue oxygen consumption in sepsis. This phenomenon possibly contributes to the ScvO₂–SvO₂ mismatch in patients with low CO by adding more oxygenated venous blood to flow through the superior vena cava. The aim of present study was to determine the relationship between the StO₂ deceleration rate and the ScvO₂–SvO₂ difference in septic patients with low CO. …