Continuous right ventricular end-diastolic volume index is more relevant than the use of pressure values to guide interventions to influence cardiac output in cardiac surgical patients

GRAZ-01-30 Introduction: As the impact of right ventricular function on cardiac performance is increasingly recognized, a new pulmonary artery catheter (PAC) has been developed to assess right ventricular parameters and cardiac output continuously. Using this new PAC, we evaluated the association between pressure preload indicators (central venous pressure, CVP; pulmonary artery wedge pressure, PAWP; continuously measured right ventricular end-diastolic volume index, cRVEDVI) and continuous cardiac output (cCO) in cardiac surgical patients. Methods: Following institutional approval and informed consent, patients undergoing elective coronary artery bypass grafting were studied. A new PAC (CEDV-Catheter 744H®; Baxter Healthcare Corp., Irvine, CA, USA) connected to a computerized monitoring system (Vigilance® CCO/SvO2/CEDV; Baxter Healthcare Corp.) was used to determine CVP, PAWP, cRVEDVI, and cCO. Measurements were recorded at eight predefined time points (1 h, 2 h, 3 h, 4 h, 6 h, 8 h, 10 h, and 12 h) after weaning from cardiopulmonary bypass. Statistical analysis was performed using linear regression of data pairs and Pearson's correlation coefficient (r). Results: Overall, 80 measurements have been conducted in 10 patients (60.8 ± 7.9 yr). During the entire study period, no correlation was found between CVP and cCO (r = 0.27; P = n.s.), and between PAWP and cCO (r = 0.32; P = n.s.). In contrast, a significant positive correlation was documented between cRVEDVI and cCO (r = 0.68; P < 0.01). Conclusions: These data indicate that continuous assessment of right ventricular volume parameters like cRVEDVI is clinically more relevant than the use of pressure values with regard to the haemodynamic state of the patient. In conclusion, the new PAC is a useful monitoring device to guide interventions to influence CO in cardiac surgical patients.