Effects Of Acute Normovolemic Hemodilution On Intestinal Oxygen Metabolism In Anesthetized Rabbits

【Objective】To observe the effects of acute normovolemic hemodilution(ANH) on intestinal oxygen metabolism in anesthetized rabbits ,and investigate the limits of ANH that result in intestinal anaerobic metabolism. To study the tendence of intestinal and systemic oxygen metabolism.【Methods】 Twenty-eight rabbits were divided into three hemodilution groups( H1, H2 and H3 groups) and one control group (H0 group) randomly. The different degree of ANH ,namely moderate( H1 ,Hct = 24.33%) ,severe ( H2, Hct = 14.97%) and extreme(H3 ,Hct =9.59% ),were accomplished by exchanging whole blood with 4% Gelofusion. Superior mesenteric arterial and superior mesenteric venous blood gas, femoral arterial and internal jugular venous blood gas, femoral arterial blood lactate value(ABL), superior mesenteric venous and internal jugular venous blood lactate value (VBL) ,were measured prior to hemodilution and 1 hour after hemodilution . Diference of oxygen content , oxygen extraction ratio(ERO2) and venous-arterial difference of lactate (VADL) were calculated. 【Results】Mean arterial pressure of all rabbits were stable, and heart rate increasedafter ANH in H2 and H3 groups. As compared with H0 group,both intestinal and systemic CaO2 ,CvO2 decreased significantly after ANH in H1,H2 and H3 groups. There was a significant(P<0.01) increase in ERO2 after ANH in H2 and H3 groups; whereas no significant difference was found in H1 group. ABL ,VBL and VADL increased significantly after ANH in H3 group; and no change was found in H1 and H2 groups. Compared to what was measured before ANH, the tendency was the same as that comparing with H0, besides ERO2 was higher in H1 group .No significant difference was found between all groups before ANH .All of intestinal and systemic mesurements in the same group had no difference. 【Conclusions】 This study suggests that moderate ANH do not affect intestinal oxygen metabolism; severe ANH change intestinal oxygen metabolism,but can be compensated; extreme ANH result in intestinal anaerobic metabolism. Systemic and intestinal oxygen metabolisms are changed at the same ANH degree.