Stroke volume variation derived by arterial pulse contour analysis is a good indicator for preload estimation during liver transplantation

Background: Accurate determination of preload during liver transplantation is essential. Continuous right ventricular end diastolic volume index (RVEDVI) has been shown to be a better preload indicator during liver transplantation than the filling pressures. However, recent evidence has shown that dynamic variables, in this case stroke volume variation (SVV), are also good indicators of preload responsiveness. In this study, we evaluated the correlation between SVV, which we derived from arterial pulse contour analysis and RVEDVI. Methods: In this study, we looked for possible relationships between SVV obtained through FloTrac/Vigileo monitor, central venous pressure (CVP), pulmonary arterial occlusion pressure (PAOP), and RVEDVI in 30 patients undergoing liver transplantation. Measurements were taken at 11 defined points during different phases across liver transplantation. Each set of measurement was taken during a steady state, which means at least 15 minutes elpased after any changes occured in either the infusion rate of catecholamines or ventilator settings. Pearson's test was used for correlation estimation. Results: There was a statistically significant (P <.01) relationship between SVV and RVEDVI with a correlation coefficient of -0.87. The correlations between CVP (r = 0.42), PAOA (r = 0.46), and RVEDVI were less strong. Conclusion: We conclude that SVV is a good indicator for preload estimation during liver transplantation. A higher SVV value is associated with a more hypovolemic fluid status.