Continuous cardiac output monitoring by the Fick method

Current methods for longitudinal assessment of cardiac output in severely ill patients are intermittent only and in many respects appear unsatisfactory. We have developed a computerized on-line system for continuous Fick cardiac output monitoring, utilizing fiberoptic arterial and pulmonary arterial probes with a metabolic analyzer for VO2. In 15 patients, cardiac output ranged 1.9-6.8 L/min and 12 were within 5% of thermodilution values. Continuous output monitoring during interventions in two patients (saline infusion and coronary angioplasty) illustrate the utility of the technique. Two additional patients had unsatisfactory VO2 data due to low airflow velocity. The results of this pilot study suggest that cardiac output monitoring by the Fick method may have clinical and investigational uses in intensive care units and during cardiac catheterization or surgical procedures.