Comparison of pulmonary artery and aortic transpulmonary thermodilution for monitoring of cardiac output in patients with severe heart failure: validation of a novel method.

OBJECTIVE: Hemodynamic monitoring with the pulmonary artery catheter is frequently used in the management of severe heart failure. For measurement of cardiac output (CO), transpulmonary thermodilution (TPTD) has recently been adopted into clinical practice as an alternative to pulmonary artery thermodilution. However, no data have been published on the comparability of the two methods for patients with severely reduced left ventricular function. Our objective was to evaluate the correlation between these two methods of CO determination in patients with severe left ventricular dysfunction.
DESIGN: Prospective observational clinical study.
SETTING: Cardiological intermediate care unit and medical intensive care unit of a university hospital. PATIENTS: Twenty-nine patients with left ventricular ejection fraction <35% and symptoms of heart failure (New York Heart Association class III-IV). INTERVENTION: None.
MEASUREMENTS AND MAIN RESULTS: The two methods of intermittent CO measurement were compared by simultaneously recording the results of pulmonary artery thermodilution and TPTD after injection of a cold saline bolus. Measurements were performed when clinically necessary. A total of 325 data pairs were analyzed. Mean CO of both methods was 4.4 L/min with a bias of 0.45 L/min (2 SD 1.20 L/min), resulting in a percentage error of 27.3%.
CONCLUSION: In patients with severely impaired left ventricular function, measurement of CO by TPTD provides valid results.