Cardiac output measured by thermodilution in infants and children

To determine the accuracy and reproducibility of cardiac output determinations by thermodilution (CO_T) in children, simultaneous outputs were measured by the Fick technique (CO_F) (using measured oxygen consumption) and thermodilution in 26 children, ranging in age from 8 to 86 months, who were undergoing cardiac catheterization. There was excellent correlation between mean output by thermodilution and by the Fick technique: CO_T=1.10 CO_F−0.2 l/minute, r=0.91. In three-quarters of the patients the CO_T differed by 15% or less and in none differed by more than 25%. Serial values of thermodilution outputs were reproducible in each patient with a SD of 5.5%. Our observations indicate that CO_T is accurate, reproducible, and valuable in the care of critically ill infants and children.