Background and objective: Intraoperative management of patients with end-stage liver disease undergoing liver transplantation requires fluid administration to increase cardiac output and oxygen delivery to the tissues. Filling pressures have been widely shown to correlate poorly with changes in cardiac output in the critically ill patient. Continuous right ventricular end-diastolic volume index (cRVEDVI) and left ventricular end-diastolic area index (LVEDAI) monitoring have been increasingly used for preload assessment. The aim of this study was to compare cRVEDVI, LVEDAI, central venous pressure and pulmonary artery occlusion pressure with respect to stroke volume index (SVI) during liver transplantation.
Methods: Measurements were made in 20 patients at four predefined steps during liver transplantation. Univariate and multivariate panel-data fixed effect regression models (across phases of the surgical procedure) were fitted to assess associations between SVI and cRVEDVI, pulmonary artery occlusion pressure, central venous pressure and LVEDAI after adjusting for ejection fraction (categorized as <or=30, 31-40, >40).
Results: SVI was associated with continuous right ventricular ejection fraction. The model showing the best fit to the data was that including cRVEDVI: even after adjusting for continuous right ventricular ejection fraction and phase, the regression coefficient of cRVEDVI in predicting SVI was statistically significant and indicated an increase in SVI of 0.21 ml m(-2) for each increase of 1 ml m(-2). At the multivariate analysis, an increase in LVEDAI of 1 cm m(-2) led to an increase in SVI of 1.47 ml m(-2) (P = 0.054).
Conclusion: cRVEDVI and LVEDAI gave a better reflection of preload than filling pressure, even if only cRVEDVI reached statistical significance.