Objective: To compare measurements of cardiac output using a new pulmonary artery catheter with those obtained using two "gold standard" methods: the periaortic transit time ultrasonic flow probe and the conventional pulmonary artery thermodilution.
Design: Prospective clinical trial.
Setting: Cardiac surgery operating room and surgical ICU in a university hospital.
Material and methods: In the operating room, a new pulmonary artery catheter (truCCOMS system) was inserted in eight patients. A periaortic flow probe was inserted in four of them. Measurements of cardiac output obtained with the truCCOMS catheter and with the flow probe were compared at different phases of the surgical procedure. In the intensive care unit, the cardiac output displayed by the truCCOMS monitor was compared with the value obtained after bolus injection performed subsequently.
Results: In the operating room (70 measurements), the coefficient of correlation between cardiac output measured by the flow probe and the truCCOMS system was r2 = 0.79, the bias was +0.11 l/min with a precision of 0.47 l/min, and limits of agreement -0.83 to +1.05 l/min. In the intensive care unit (108 measurements), the coefficient of correlation between cardiac output measured by thermodilution and the truCCOMS system was r2 = 0.56, the bias was -0.07 l/min, the precision was 0.66 l/min, and the limits of agreement were -1.39 to +1.25 l/min.
Conclusion: The truCCOMS system is a reliable method of continuous cardiac output measurement in cardiac surgery patients.