Cardiac output determination: thermodilution versus a new computerized Fick method.

A computerized system is described for the on-line analysis of respiratory flow, complete analysis of inspired and expired gas, and computation of oxygen consumption and carbon dioxide production. The system has been compared to traditional Douglas bag determinations of these quantities. Fick cardiac output using computed oxygen consumption (VO2) was highly correlated (r = .92, p less than .001) with thermodilution cardiac output, determined simultaneously. Moreover, the computerized Fick method was much more reproducible.