Transcardiopulmonary vs pulmonary arterial thermodilution methods for hemodynamic monitoring of burned patients.

The objective of this study was to validate a new method of transcardiopulmonary thermodilution for assessment of cardiac index (CI), stroke volume index (SVI), systemic vascular resistance index (SVRI) and additional parameters such as intrathoracic blood volume index and extravascular lung water index (EVLWI) by comparison with conventional pulmonary artery catheter values in a severely burned population. The pulmonary artery measurements were performed continuously with the Vigilance system, and the transcardiopulmonary thermodilution with the PiCCO(R) system. One hundred thirteen measurements with each system on up to six consecutive days were taken in 14 severely burned patients (average TBSA, 49.6%; average ABSI, 10.3), aged 21 to 61 years (mean, 42.2 years) and compared intraindividually. An excellent correlation between the two methods was shown for CI (r = 0.80) and its derived parameters SVI and SVRI in states of low to normal cardiac output. The correlation was poor for cardiac indices greater then 5.5 up to their maximum values (r = 0.46). No correlation between index of oxygenation (PaO2/FiO2) vs EVLW I was observed. There was no difference between survivors and nonsurvivors, and between patients with and without inhalation injury in EVLWI. The method of transcardiopulmonary thermodilution is suitable to assess SVI, CI and SVRI under the special pathophysiologic condition of a major burn for low to normal cardiac output states. It is less reliable when cardiac output is high. The lower cost and less invasive nature are the advantages of the system compared with use of the pulmonary artery catheter. The role of intrathoracic blood volume index and EVLWI in cardiopulmonary monitoring of severely burned patients remains to be further determined.