ABSTRACT
Our hypothesis is that hypercarbia produces sympathetic stimulant effect and local vasodilatation. We studied the effect of intentional hypercarbia [IHC] on hepatic venous oxygen saturation. The hepatic vein [HV] was cannulated in 15 patients through either the right internal jugular vein or the femoral vein to measure HV oxygen saturation and calculate oxygen content. The inferior vena cava [IVC] was cannulated in 6 patients above and below drainage of the hepatic veins for oxygen saturation and content difference along the IVC. IHC was achieved in awake patients by breathing oxygen enriched air at a flow rate of 2L/ min for 10 min, and during anesthesia by increasing anesthetic dead space and reducing tidal volume. IHC increased HV blood oxygen saturation, decreased the arterio-hepatic vein oxygen content difference and decreased oxygen saturation difference and oxygen content difference along IVC