What causes low oxygen extraction in sepsis/septic shock?

Updated: Oct 07, 2020
  • Author: Andre Kalil, MD, MPH; Chief Editor: Michael R Pinsky, MD, CM, Dr(HC), FCCP, FAPS, MCCM  more...
  • Print
Answer

In patients experiencing septic shock, oxygen delivery is relatively high, but the global oxygen extraction ratio is relatively low. Oxygen uptake increases with rising body temperature despite a fall in oxygen extraction.

In patients with sepsis who have low oxygen extraction and elevated arterial lactate levels, oxygen uptake depends on oxygen supply over a much wider range than normal. Therefore, oxygen extraction may be too low for tissue needs at a given oxygen supply, and oxygen uptake may increase with a boost in oxygen supply—a phenomenon termed oxygen uptake supply dependence or pathologic supply dependence. This concept is controversial, however; some investigators argue that supply dependence is an artifact rather than a real phenomenon.

Maldistribution of blood flow, disturbances in the microcirculation, and, consequently, peripheral shunting of oxygen are responsible for diminished oxygen extraction and uptake, pathologic supply dependency of oxygen, and lactate acidemia in patients experiencing septic shock.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!