Fig. 1
From: Influence of clonidine induced sympathicolysis on anaemia tolerance in anaesthetized pigs
a Typical example of an oxygen consumption (VO2) recording in the course of the experimental protocol. A linear regression analysis including the calculation of standard deviation was performed with VO2 values collected during the 60-min stabilization period. During the subsequent hemodilution protocol, a critical limitation of DO2 was assumed, when the actually measured VO2 value decreased below the lower 3 s. b Dependency of oxygen consumption (VO2) on oxygen delivery (DO2) during normovolemic anemia. The graph presentation of Fig. 1 panel is reflected around a vertical axis (with the x-axis to the right of the y-axis) to match the decreasing VO2 along the timeline of panel a. In panel b DO2 decreases from left to right along the x-axis and VO2 decreases from top to bottom along the y-axis. Despite an initial decrease of DO2, VO2 remains stable over a long period (DO2 is independent of VO2). If a critical hemoglobin concentration (Hbcrit) is reached, VO2 starts to decrease because of a critical restriction (DO2 dependent on VO2)