The effect of enteral oxygen administration on the hepatic circulation during halothane anaesthesia: clinical observations.

A study of the estimated hepatic blood flow (EHBF) using a colloidal gold technique in 28 patients undergoing saphenous vein stripping, showed that the EHBF decreased to 68% of its initial value during the period of halothane anaeshtesia and operation. When enteral oxygen was added EHBF increased to 82% of its initial value. An investigation in 14 other patients under going upper abdominal operations showed that enteral oxygen administration caused the oxygen saturation of the portal blood to increase from 55+/-7.2% (mean +/- SEM) to 80+/-6.2% and, by producing a concomitant decrease in portal pressure, led to a reduction in the portocaval pressure gradient from 74+/-12.5 to 38+/-8.7 mm H2O. It is suggested that the oxygen content of the portal blood per se influences the tone of hepatic presinusoidal sphincters. It is concluded that enteral oxygen administration may minimize disturbances in the hepatic circulation occurring during halothane anaesthesia and surgical operations.