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/m2


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.