Effects Of Acute Hypervolemic Hemodilution On Cerebral Oxygen Metabolism

【Objective】To observe the effects of acute hypervolemic hemodilution(AHH) on cerebral oxygen metablism and investigate whether AHH can result in cerebral hyperperfusion. 【Methods】 Twenty-three patients, ASA grade Ⅰto Ⅱ, undergoing lebectomy of liver or hepatolithedomy with general anesthesia were acted as subjects. They were divided into hemodilution group(H group,n=12) and control group(C group,n=11) randomly. The changes of arterial and jugular venous hemoglobin saturation(SjvO2) and lactate value were measured before AHH(T0), 10min after AHH(T1) ,30min after AHH (T2) and 1h after AHH(T3) .Diference of oxygen content and lactate difference between arterial and jugular bulb blood (Da-jvO2),cerebral extraction of oxygen(CEO2) were caculated. 【Results】 hemodynamics of all patients were stable.In H group, though CVP increased significantly after AHH,but within normal range.There was a significant(P<0.01) increase in the median SjvO2 at T1-T3, whereas both CEO2 and Da-jvO2 decreased significantly at T1-T3.Three of the patients had a SjvO2 more than 90%;comparing with C group at the corresponding time point,the difference of SjvO2,CEO2 and Da-jvO2 were significant at T1 only.In C group,the tendency is the same as that in H group as to the change of SjvO2,but there was no patient,s value of SjvO2 beyond 80%. In two groups,no changes occurred to VADL all the time. 【Conclusions】 This study suggests that cerebral oxygen balance during AHH is well maintained in most patients, but cerebral hyperperfusion might occur in a few of patients.