In their manuscript Creteur, Neves and Vincent describe the effects of allogeneic red blood cell (RBC) transfusion on parameters of tissue perfusion and oxygenation in 44 critically ill patients. The data were obtained with near-infrared spectroscopy on the surface of the thenar muscle. In case of manifest tissue hypoxia and altered microperfusion, RBC transfusion improved tissue oxygenation and perfusion. The opposite was observed when tissue oxygenation and perfusion were basically preserved. The effects were independent of the storage time of RBCs. The basic principles of the regulation of microperfusion and tissue oxygenation are nicely reviewed in the discussion.
– Oliver Habler