Objective: To observe the changes of systemic and pulmonary hemodynamics and the plasma levels of inducible nitric oxide synthase (iNOS) and endothelin-1 (ET-1) and investigate their association in patients with hepatopulmonary syndrome (HPS).
Methods: Twenty-six patients with HPS undergoing orthotopic liver transplantation (OLT) were enrolled in this study with 20 patients without hypoxemia as the control group. Blood samples were taken one day before OLT to measure the plasma levels of iNOS and ET-1 using fluorescence quantitative polymerase chain reaction (FQ-PCR) and radioimmunoassay, respectively, with 10 healthy volunteers serving as the healthy control group. Before the operation for OLT, the parameters of systemic and pulmonary hemodynamics were monitored after anesthesia induction.
Results: The systemic and pulmonary hemodynamics in patients without hypoxemia was characterized by high cardiac output and low resistance, and by comparison, the patients with HPS showed even higher cardiac output and lower mean pulmonary artery pressure, pulmonary artery wedge pressure, systemic vascular resistance and pulmonary vascular resistance. The two patient groups had comparable plasma iNOS and ET-1 levels, which were both higher than those in the healthy control group.
Conclusion: The hemodynamics in patients with end-stage liver disease exhibit a pattern of high cardiac output and low resistance, which is more obvious in HPS patients possibly in association with elevated plasma levels of iNOS and ET-1.