The Effect Of Preoperative Acute Hypervolemic Hemodilution On Hemodynamics And Body Internal Environment Homeostasis In Patients Undergoing Meningioma Resection

Backgrouds and Objective: The complications caused by xenogenoustransfusion become more and more in recent years. Among these complications, Hepatitis and AIDS derived from the infection of virus have become a serious social problem. In new century,our country will face the more severe situation such as defict of blood source and more serious infection after transfusion. So how to save blood is an important medical studying topic.Acute hypervolemic hemodilution(AHHD) has been an effective method used in anesthesia recently to reduce the loss of blood cells during intraoperative bleeding. Comparing with acute normovolemic hemodilution (ANH), AHHD is easier, less time consuming, and less expensive. For blood losses<40% of blood AHHD appears the same efficiency. The kind of fluid , the infusion rate and the volume of acute hypervolemic hemodilution are still controversial. People still have different opinions about its performing methods, the degree of tolerance et al, and its reliability and effectiveness of saving blood also have to be more discussed. So in this study the patients undergoing scheduled elective meningioma operation were randomly divided into 3 groups: Group L (AHHD with lactated Ringer' s solution), Group V (AHHD with 6% Hydroxyethyl Starch130/0.4), Group G(AHHD with Succinylated Gelatin), to observing the changes of hemodynamics and body internal environment homeostasis . The purpose of this study is to assess the feasibility and effect of acute hypervolemic hemodilution increasing blood volume, maintaining hemodynamics and body internal environment homeostasis , and to provide clinical bases for its administration in anesthesia.Materials and methods: Thirty patients (16 men and 14 women), ASA I～II, HCT=35%, HB> 110g.L^-1 undergoing scheduled elective meningioma operation were randomly divided into 3 groups: Group L (AHHD with lactated Ringer's solution), Group V (AHHD with 6% Hydroxyethyl Starch130/0.4), Group G(AHHD with 4% Succinylated Gelatin), with 10 in each group. The anesthesia induction and drug of anesthesia maintenance are all the same. The patients were premedicated with intramuscular hyoscine 0.3mg and luminal 0.1g. Anesthesia was induced with midazolam 0.1mg·kg^-1, fentanyl 3ug·kg^-1, propofol 2mg·kg^-1 and scoline 1.0mg·kg^-1 and maintained with propofol 6-8mg·kg^-1—h^-1. Muscle relaxation was maintained with intermittent intravenous boluses of vecuronium and fentanyl. The patients were mechanically ventilated after tracheal intubation and P_ETCO₂ was maintained at 4.66-5.32KPa. Right internal jugular vein and left radialis artery were cannulated. Radialis artery was cannulated for intra-arterial pressure monitoring and blood sampling, Right internal jugular vein were cannulated for CVP monitoring and blood sampling. In all patients, 0.9%NS 6-8 ml·kg^-1·h^-1 was infused to compensate for preoperative fluid restriction after midnight. AHHD was performed by infusing 10ml·kg^-1 solution (Group L, AHHD with lactated Ringer's solution; Group V, AHHD with 6% Hydroxyethyl Starchl30/0.4 ; Group G, AHHD with 4% Succinylated Gelatin) before induction and 10ml·kg^-1 solution during and after induction. During operation blood loss was replaced with equal volume of 6% Hydroxyethyl Starch130/0.4 or 4% Succinylated Gelatin . Blood transfusion was considered to maintain HCT>25%, When Hb<80 g.L^-1 and HCT<25%. MAP (Mean Arterial Pressure), HR (Heart Rate), CVP (Central Venous Pressure), SpO₂ (pulse oxygen saturation), PetCO₂ were monitored continually during the whole experiment. HR,MAP,and CVP was recorded before AHHD(T0, baseline),AHHD 10ml·kg^-1 (T1),AHHD20ml·kg^-1(at the end of AHHD,T2),30minute after AHHD (T3),60minute after AHHD(T4),120minute after AHHD(T5) respectively. Collect arterial blood samples before AHHD (T0,baseline),at the end of AHHD(T2),60 minute after AHHD (T4),120 minute after AHHD(T5) respectively for determining blood gases; Collect venous blood samples for determining the following data :â‘ Blood routine examination (including HCT,HB,PLT);â‘¡Routine coagulation test (including PT,TT,APTT,FBG) and VIII,VWF;â‘¢Electrolytes ; Collect urine samples for determining urinary N-acetyl-β-glucosaminidase (NAG). The data were expressed as mean±SD. Statistical package (SPSS 10.0) was used for processing all the data . An analysis of variance for repeated measures, Fisher's exact test were employed to analyze the data . a=0.05 was considered that the diference has statistical significance.Results:1. General dataThere were no significant diferences among three groups on age, weight and sex.2.Changes on hemodynamicsChanges on HR: There were no significant differences among and within three groups P>0.05.Changes on MAP: There were no significant differences within three groups P>0.05. Compare between groups: there were significant differences between group V and group L P<0.05.Changes on CVP: There were significant differences among and within three groups P < 0.05 .Within three groups, compared with T0, the CVP increased significantly at T1～T4 P<0.05. Compare between groups: There were significant differences between group V and group L P<0.05.3. Changes on blood routine examination Changes on HCT: Within three groups, the HCT decreased significantly at T2,T4,T5 compared with T0 P<0.05. Compare between groups: There were significant differences between group V and group L P<0.05.Changes on HB: Within three groups, the HB decreased significantly at T2,T4,T5 compared with T0 P<0.05. Compare between groups: There were significant differences between group V and group L P<0.05 .Changes on PLT: Within three groups, the PLT decreased significantly at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P>0.05.4. Changes on function of blood coagulationChanges on PT: Within three groups, the PT was significantly longer at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P>0.05.Changes on TT: Within three groups, the TT was significantly shorter at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P>0.05.Changes on APTT: Within three groups, the APTT was significantly longer at T2,T4,T5 compared with T0 P<0.05. Compare between groups: There were significant differences between group G,group V and group L P<0.05 .Changes on FBG: Within three groups, the FBG decreased significantly at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P>0.05 .Changes on VIII: Within three groups, the VIII decreased significantly at T2,T4,T5 compared with T0 P<0.05. Compare between groups: There were significant differences between group G,group V and group L P<0.05 .Changes on VWF: Within three groups, the VWF decreased significantly at T2,T4,T5 compared with T0 P<0.05. Compare between groups: There were significant differences between group G,group V and group L P<0.05.5.Changes on analysis of blood gasesChanges on PH: There were no significant differences within three groups P>0.05. Compare between groups: There were significant differences between group V and group L P<0.05.Changes on HCO₃^- : Within three groups, the HCO₃^- decreased significantly at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P > 0.05.Changes on PaO₂ : Within three groups, the PaO₂ increased significantly at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P>0.05.Changes on PaCO₂ : Within three groups, the PaCO₂ decreased significantly at T2,T4,T5 compared with T0 P<0.05. There were no significant differences among three groups P>0.05.6. Changes on electrolytesChanges on Na⁺ : Within three groups, compared with T0, Na⁺ increased significantly at T2 P<0.05; Na⁺ decreased significantly at T4,T5 P<0.05 .There were no significant differences among three groups P>0.05.Changes on K⁺ : There were no significant differences among and within three groups P>0.05.Changes on CL^- : Within three groups, compared with T0, CL^- increased significantly at T2 P<0.05 . There were no significant differences among three groups P>0.05.Changes on Ca²⁺ : Within three groups, there were significant differences at T2,T4,T5 compared with T0 P<0.05. Compare between groups: There were significant differences between group G,group V and group L P<0.05.7. Changes on NAG: There were no significant differences among and within three groups P>0.05.8. Changes on blood transfusion,dose of intraoperative transfusion and urine :Intraoperative blood transfusion volume decreased significantly P<0.05 in group V and group G compared with group L, and there were no significant differences between group V and group G p>0.05. No significant differences among three groups were found in intraoperative blood loss (measured by weighting sponges and calculating intraoperative suctioned blood) and dose of intraoperative transfusion p>0.05. Dose of intraoperative urine decreased significantly P<0.05 in group V and group G compared with group L, and there were no significant differences between group V and group G p>0.05.Conclusions:1. Preoperative AHHD can maintain stable hemodynamics during operation.2. When we perform AHHD by infusing 20ml·kg^-1·h^-1 solution, compared with lactated Ringer' s solution , 6% Hydroxyethyl Starch 130/0.4 and 4% Succinylated Gelatin can prolong APTT,but there were no abnormal hemorrhage and blood coagulation under clinical survey.3. AHHD has no significant effect on the analysis of blood gas.4. Compared with lactated Ringer' s solution ,Ca²⁺ decreased in group V and group G. Attentions should be taken and supplement Ca²⁺ necessarily.5. Preoperative AHHD and three kinds of fluid we used in this study have no detrimental effect on renal function in patients with normal function.6. Preoprative AHHD can effectively expand the blood volume, 6% Hydroxyethyl Starch 130/0.4 and 4% Succinylated Gelatin are more reliable than lactated Ringer' s solution in its volume expansion effect. Compared with crystalloid, colloid is more effective in blood saving.