2] is the only predictor of mortality may be explained on the basis the pulmonary shunt present if HPS individuals, due to the disrupted oxygen diffusion capacity as a consequence of capillary vasodilation, in addition to a shortened erythrocyte transit time through the capillaries and an elevated cardiac output.
First, the value of pulmonary shunt fraction (Qs/Qt) was not given in the present study, since it requires invasive pulmonary artery catheterisation for the sampling of mixed venous whole blood.