Right Ventricular End-Diastolic Volume Index as a Predictor of Preload Status in Patients With Low Right Ventricular Ejection Fraction During Orthotopic Liver Transplantation

Abstract

Objective The objective of this study was to compare the accuracy of 2 variables: pulmonary artery occlusion pressure (PAOP) and right ventricular end diastolic volume index (RVEDVI) as predictors of the hemodynamic response to fluid challenge as well as definition of the overall correlation between RVEDVI and change in PAOP, right ventricular ejection fraction (RVEF), central venous pressure (CVP), and determination of the right ventricular function during orthotopic liver transplantation. Materials and Methods A modified pulmonary artery catheter equipped with a fast response thermistor was used to determine RVEF, allowing calculation of RVEF end-diastolic volume index (EDVI, as the ratio of stroke index [SI] to EF). The above-mentioned hemodynamic measures were taken in 4 phases: T0, after induction of anesthesia; T1, during anhepatic phase; T2, 30’ after graft reperfusion; and T3, at the end of surgery. Results The variation of the REF value was 36 ± 4% and 39 ± 6%. Linear regression analysis showed a significant correlation between RVEDVI (range, 133 ± 33–145 ± 40 mL/m 2) and stroke volume index (SVI) in each phase ( r 2 = 0.49, P < .01; r 2 = 0.57, P < .01) at T0 and T1, respectively, and at T2 and T3 ( r 2 = 0.51, P < .01; r 2 = 0.44, P < .01), respectively. No significant variations in the linear regression analysis between RVEDVI, PAOP, CVP, and RVEF were observed. No relationship was found between PAOP (range, 10 ± 2–6 ± 2 mm Hg) and SVI. Conclusion RVEDVI may be the best clinical estimate of right ventricular preload. In fact, minor changes of RVEF have been recorded, confirming that RV function was not altered during uncomplicated orthotopic liver transplantation.