Oxygenation

Oxygen Suppy and Demand

ScvO₂ – Central Venous Oxygen Saturation (via Standard-CVC)

• Early indication of an imbalance between oxygen consumption (VO₂I) and oxygen delivery (DO₂I)
• Good clinical correlation between ScvO₂ and SvO₂ (mixed venous oxygenation measured via a PA- catheter)
• Less invasive than mixed venous SvO₂ measurement via PA-catheter
• High impact on patient outcome (EGDT)
• ScvO₂: 70-80%
• (SvO₂: 65-75%)

DO₂I  – Oxygen Delivery Index

• Calculated from the cardiac output, hemoglobin and arterial oxygen saturation (without dissolved oxygen)
• DO₂I= CI x Hb x 1.34 x SaO₂
• DO₂I indexed to body surface area
• DO₂I: 400 - 650 ml/min/m^₂

VO₂I – Oxygen Consumption Index

• Calculated from the cardiac output, hemoglobin, arterial and mixed-venous oxygen saturation, here ScvO₂ is used instead of SvO₂ (without dissolved oxygen)
• VO₂I= CI x Hb x 1.34 x (SaO₂ – ScvO₂)
• VO₂I indexed to body surface area
• VO₂: 125 - 175 ml/min/m²

If ScVO₂ is below the normal range the reason why must be identified.