Fig. 7. Single-experiment depiction of the serum concentration of epinephrine during the course of the experiment. Note the different scales of the y-axes. bl = baseline; G 0.21 = group with a fraction of inspired oxygen (Fio2) of 0.21; G 1.0 = group with an Fio2of 1.0; Hbcrit= critical hemoglobin concentration.