Mean Systemic Filling Pressure Trends in Liver Transplant Recipients: An Observational Pilot Study

Mean systemic filling pressure is a key determinant of venous return and cardiovascular function, with potential implications for hemodynamic stability in surgical interventions, such as liver transplantation. In this prospective observational pilot study, we investigated changes in mean systemic filling pressure in patients undergoing living related donor liver transplant (primary outcome) and its correlation with various hemodynamic and intraoperative parameters (secondary outcomes).

This study was conducted at a tertiary care hospital between May 2020 and October 2020. We obtained 193 mean systemic filling pressure values from 20 adult patients (aged 18-65 y) undergoing living related donor liver transplant. We analyzed mean systemic filling pressure, heart rate, central venous pressure, mean arterial pressure, cardiac output, systemic vascular resistance, and stroke volume variation measured at baseline and during surgery. Mean systemic filling pressure was assessed by using the arm technique.

The baseline mean systemic filling pressure was 35.7 ± 8.6 mm Hg. During dissection (n = 114 mean systemic filling pressure results), anhepatic (n = 39 results), and neo-hepatic (n = 40 results) phases, mean systemic filling pressure was 31.1 ± 8.3, 26.7 ± 5.8, and 27.9 ± 6.1 mm Hg, respectively (P = .002). Among the hemodynamic variables, mean systemic filling pressure was positively correlated with central venous pressure (r = 0.69, P = .001) and negatively correlated with cardiac output (r = -0.53, P = .015).

Mean systemic filling pressure values tended to decrease during the anhepatic phase and increase during the neo-hepatic phase. Although we observed strong positive correlation between mean systemic filling pressure and central venous pressure throughout surgery,the expected positive correlation between mean systemic filling pressure and cardiac output was not observed.