The application of acute normovolemic hemodilution in spinal tumor operation

Abstract

Objective To evaluate the applied value of acute normovolemic hemodilution (ANH) in massive spinal tumor surgery bleeding. Methods 100 patients undergoing operation of spinal tumor removal under general anesthesia were selected-52 males and 48 females, with age ranging from 39 to 60 years old. Participants with American Society of Anesthesiologist (ASA) Ⅰ-Ⅱ randomly divided into two groups: ANH group (group A) and control group (group C), with 50 patients in each. Group A received ANH under general anesthesia, targeting 32% hematocrit (Hct). During exsanguination, blood was diluted with identical volume of hydroxyethyl starch 130/0.4 and sodium chloride injection. Group C was not given ANH. The dynamic changes of fast thrombelastogram (r-TEG) indicators [coagulation factor activity (ACT), K, Angle, maximum aggregation (MA), MA 30 min thrombosis and fibrinolysis percentage (EPL/LY30)] were recorded at four time points: before ANH (T1), 10 min after ANH (T2), after tumors were removed and bleeding stopped (T3) and when ANH autologous blood transfusion was completed (T4), respectively. Results At T1 and T2, r-TEG indicators in groups A and C had no significant change, and the difference between group A and group C showed no statistically significant difference. In group A, the ACT values at T1, T3 and T4 were (101.0±8.0), (131.0±10.0) and (122.0±11.0) respectively, with the difference being statistically significant (P=0.001); the K values were (1.5±0.3), (2.4±0.1) and (1.9±0.2), with the difference being statistically significant (P=0.001); the Angle values were (68.4±2.2), (63.0±2.1) and (70.0±5.0), with the difference being statistically significant (P=0.001); the MA values were (56.1±2.0), (48.5±2.1) and (49.6±1.2), with the difference being statistically significant (P=0.001). In group C at T1, T3 and T4, the ATC values were (102.0±7.6), (130.0±11.1) and (135.0±10.5), with the difference being statistically significant (P=0.001); the K values were (1.50±0.20), (2.30±0.15) and (2.53±0.16), with the difference being statistically significant (P=0.001); the Angle values were (68.5±2.1), (63.5±2.6) and (60.1±2.5), with the difference being statistically significant (P=0.001); the MA values were (58.2±3.1), (48.6±2.0) and (43.4±2.5), with the difference being statistically significant (P=0.001). Introperative blood loss, transfusion volume, operative time, and postoperative drainage volume in group C were significantly increased as compared with those in group A. Conclusion ANH can effectively improve patients’ blood coagulation function, save blood resources, reduce allogeneic erythrocytes transfusions, shorten operative time, and decrease chances of infections. As such, it is reasonable to promote the application of ANH in spinal tumor removal surgery. Key words: Acute normovolemic hemodilution; Spinal tumor; Thrombelastography