Fig. 2. Comparison between cardiac output (CO; l/min) measurements obtained by pulmonary artery thermodilution (CO^pa) and transpulmonary thermodilution (CO^aort) using within-subject correlation (  A ) and Bland-Altman plot (  B ) (within-subject correlation  r ²= 0.95; bias =−0.21 and SD = 0.51). The bias of −0.21 indicates that transpulmonary thermodilution systematically overestimates CO.  Open triangles = time 0;  closed triangles = 30 min;  closed squares = 90 min;  open squares = 150 min.