Accuracy and precision of transcardiopulmonary thermodilution in patients with cardiogenic shock

Hemodynamic monitoring plays a crucial role in the supportive treatment of critically ill patients. In this setting, the use of the pulmonary artery catheter (PAC) is a standard procedure. In this study we prospectively compare the accuracy and precision of pulmonary thermodilution (PTD) by PAC and transcardiopulmonary thermodilution (TC-PTD) in patients with cardiogenic shock following an acute cardiac event. In this prospective study 77 hemodynamic measurements were taken in 11 patients presenting cardiogenic shock (CS) treated at the medical intensive care unit of our university hospital. Hemodynamic parameters were measured simultaneously by PTD and by TC-PTD. Both techniques assessed showed a strong correlation in the obtained hemodynamic parameters. The mean bias of cardiac index between measured by PTD (CIpa) and by TC-PTD (CIpi) was 0.04 ± 0.35 L/min/m². During intra-aortic balloon pump (IABP) counterpulsation and therapeutic hypothermia (TH) in post-resuscitation care, mean bias between CIpa and CIpi was 0.04 ± 0.36 and 0.04 ± 0.34 L/min/m², respectively. Similarly, patients presenting mitral or tricuspid regurgitation showed interchangeable parameters. Preload parameters obtained by TC-PTD showed significant differences in patients with left ventricular ejection fraction (LVEF) <35 %, compared to patients with LVEF ≥35 %. In contrast, pulmonary arterial occlusion pressure showed no significant difference. Hemodynamic measurements by PTD and TC-PTD are interchangeable during therapy of CS, including patients IABP, TH, mitral or tricuspid regurgitation. Preload parameters measured by TC-PTD seem to be more accurate in these patients than pressure parameters of PTD to gather the acute hemodynamic situation.