Figure 3.

Four‐quadrant and polar plots of changes in transpulmonary thermodilution cardiac output (ΔTPTD_CO) in relation to changes in pulmonary artery thermodilution (ΔPATD_CO) using 5 mL (A and B) and 10 mL (C and D) of ice‐cold physiological saline as thermal indicator (Phase‐1); and 4‐quadrant and polar plots of changes in pulse contour analysis cardiac output (ΔPCA_CO) in relation to ΔPATD_CO (Phase‐2) during phenylephrine and nitroprusside‐induced changes in systemic vascular resistance (E and F). The exclusion zones (cardiac output changes ≤0.5 L/min) in 4‐quadrant plots (A, C, and E) are shown by the intersection of the dashed lines whereas in the polar plots they are shown by the dashed circles. Mean angular biases and radial limits of agreement of polar plots are shown by continuous and dashed lines, respectively (B, D, and F).