Iribe G.  Yamada H.  Matsunaga A.  Yoshimura N.  Effects of the phosphodiesterase III inhibitors olprinone, milrinone, and amrinone on hepatosplanchnic oxygen metabolism.  Critical Care Medicine.  28(3):743-8, 2000.


    The authors measured the hepatic venous oxygen saturation in patients after cardiac surgery and to compare the effects of olprinone (OLP), a newly synthesized phosphodiesterase III inhibitor, with those of milrinone (MIL) and amrinone (AMR) on hepatosplanchnic oxygen dynamics. Phosphodiesterase III inhibitors are used to improve the hemodynamic state after cardiac surgery. However, the effect of these agents on the hepatosplanchnic circulation has not been investigated thoroughly. In a prospective, randomized study in a University hospital intensive care unit (ICU), twenty-nine patients undergoing elective cardiac surgery. In each patient, a 7.5-Fr oximeter catheter was placed in the hepatic vein via the right femoral vein. Catheterization was completed before admission to the ICU, and the study was performed 8 to 24 hours after surgery, after obtaining stable systemic hemodynamics in the ICU. The patients were assigned randomly to three groups, and they received one of three drugs for 2 hrs (OLP group, 0.3 mcg/kg/min of OLP; MIL group, 0.5 mcg/kg/min of MIL; AMR group, 10 mcg/kg/min of AMR). The authors did not change the patient's hemodynamic interventions, including catecholamines and vasodilators, throughout the study period. Arterial and hepatic venous blood gas data and hemodynamic data (via a pulmonary artery catheter) were obtained before and after drug infusion. Using these data, the authors calculated systemic oxygen delivery and consumption, the systemic oxygen extraction ratio and the hepatosplanchnic oxygen extraction ratio, and the change in hepatosplanchnic blood flow using Fick's equation. Although the increases in cardiac index were not significantly different among the three groups, hepatic venous oxygen saturation increased significantly only in the OLP group (from 47.1% +/-2.6% to 57.0% +/- 1.5% in the OLP group, from 48.4% +/- 2.3% to 50.9% +/- 2.6% in the MIL group, and from 49.8% +/- 3.6% to 50.8% + +/-.7% in the AMR group). The calculated hepatosplanchnic blood flow change was significantly larger in the OLP group than in the other groups (30.1% +/- 5.7% in the OLP group, 9.3% +/- 5.1% in the MIL group, and 2.6% +/- 6.5% in the AMR group). The authors conclude their results suggest that OLP enhances hepatosplanchnic blood flow and thus may be beneficial in protecting the hepatosplanchnic organs after cardiac surgery.