Alleviating central venous oxygen saturation (ScvO2): a new approach of kidney protection after cardiac surgery?

In a recent article, Balzer et al. [1] reported an unexpected relationship between an initial central venous oxygen saturation (ScvO2) >80 % on ICU admission and increased morbidity and mortality in cardiac surgery patients. Interestingly, as compared with low (<60 %) or normal (60–80 %) ScvO2 levels, values above 80 % were associated with more acute kidney injury (AKI) and a higher hemodialysis need. This goes against common belief that a higher ScvO2 is a prerequisite for more optimal organ, and in particular kidney, protection. Transient brief episodes of upper arm ischemia after induction of anesthesia reduce the rate of AKI and the