Experimental Study Of Acute Normovolemic Hemodilution With Polygelatine Injection

Objective: The study is to observe the effects of acute normovolemic hemodilution with 5% Polygelatine Injection comparing with 6% hydroxyethyl starch (HAES) on, hemodynamics ,Hemorheology ,coagulation ,oxygen transport and consumption,blood gas and lactic acid in anesthesized dogs.Methods: Fourteenth healthy dogs of either sex,weighting 12-16kg,were randomly divided into two groups:5% polygelatine injection group( I), n=7 and 6% hydroxyethyl starch (HAES) group(II), n=7. The dogs were anesthesized initially with pentobarbital sodium 30 mg kg-1 administered intravenously.Intraoperative monitoring included continuous monitoring of lead II and V5 of the electrocardiogram and automated ST-segment analysis. Femoral artery was cannulated for infra-arterial blood pressure monitoring and blood gas analysis, Femoral vein was cannulated for blood sampling and infusion.Swan-ganz catheter was inserted though right external jugular vein for monitoring heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), pulmonary artery pressure(PAP),pulmonary arterial wedged pressure(PAWP), cardiac index (CI), systemic vascular resistance index (TVRI), pulmonary vascular resistance index(PVRI) and coronary perfusion pressure (CPP) throughout experiment. Arterial and central venous blood samples were taken for blood gas analysis and determination of lactic acid concentration before and after AHN. At preANH and postANH, arterial and mixed venous blood gases were obtained, for calculating oxygen consumption (VO2) and oxygen extraction rate (OER).All dogs underwent moderate hemodilution to a target Hct was of 30%. 5% Polygelatine injection and 6% hydroxyethyl starch (HAES) were administered in a 1:1 volume replacement ratio. The two groups received a maximum of 20 ml/kg of the studyfluid during hemodilution.Data was expresed as mean SD and analyzed using SPSS for Windows software (release 11.5, SPSS Institute, Chicago, IL). Changes in variables measured before and during hemodilution and recovery were analyzed statistically in each group using the Student paired t test. Differences between the two groups were also analyzed using the Student paired t test. P values <0.05 were considered statistically significant.Results: 1 ANH was well tolerated hemodynamically in two groups. Heart rate remained unchanged, or decreased slightly, whereas CI remained stable in all portions of the investigation. Mean arterial pressure do not decreased at postANH in the 5% polygelatine injection group and 6% hydroxyethyl starch (HAES) group . Systemic vascular resistance did not change significantly in both of the groups. There were no significant differences between groups at any hemodynamic data point. 2, Oxygen consumption remained stable throughout the study.Electrolytes ,pH ,PaO2 and lactate were kept stable throughout operation. None of the dogs became acidotic during the hemodilution process. ST segment changes were not observed in any dogs during or after completion of ANH in our study. 3, Blood low,middle and high shear rate viscosity after ANH were obviously lower than that before ANH. 4, Our study did not show significant degradation of coagulation capacity as indicated by PT and APTT.Conclusion Polygelation injection can be used safely for ANH in terms of hemodynamic changes and oxygen transport and consumption.