Clinical Investigations For Acute Non-normolvolemic Hemodilution

Objective: To evaluate the effectiveness of acute non-normolvolemic hemodilution (taking the advantage of acute normolvolemic hemodilution and acute hypervolemic hemodilution) and the safety by comparing the hemodynamics with that of the acute hypervolemic hemodilution.Methods: Forty ASA I-II patients( 18-65 years, PLT>10000/mm3, Hb>12g, Hct>35%, estimated blood loss >500ml) scheduled for elective operation under combined epidual and general anesthesia were randomly divided into two groups: acute hypervolemic hemodilution (group I, n=20) and acute normolvolemic hemodilution (group II, n=20). In group I: patients received lactated Ringer's solution (15/kg body weight) and hydroxyethyl starch solution (HES, 15ml/kg body weight), 15 min after induction of general anesthesia. In group II: blood (10% of the total blood volume) was removed via arterial line into continuously shaking ACD-bag 15 min after induction of anesthesia, and then infused lactated Ringer solution (15/kg body weight) and hydroxyethyl starch solution (HES, 15ml/kg body weight) rapidly. ECG, invasive blood pressure, CVP, CO, Hb and Hct were determined as follow stages: 1. before hemodilution (in group I) or before blood being removed (in group II), 2. after hemodilution, 3. in the end of operation and the first day after operation.Result: There are no differences in the baseline values between the two groups, as so as the bleeding during the operation. In group II, CVP decreased significantly after blood removed, but increased rapidly after hemodilution. The degree of increasing in group II was much less than that in group I. After h emodilution, Both CO and SV increased significantlyin either group as compared with the baseline values. The hemodilution in two groups belonged to middle or mild degree according to the lever of Hb and Hct, and the dilution effect in group II is better than that in group I. The lever of Hb and Hct in group II were higher than those in group I in the end of the operation. But there were no significant differences in statistics on the subsequent day between the two groups.Conclusion: Acute non-normolvolemic hemodilution avoided the disadvertages of AHHD (the window of low Hct and large blood volume). On the other hand, it was easy to perform,and showed safe and effective for blood save.