The Study Of Oxygen-carrying Capacity Of Packed Red Blood Cells During The Preservation Process

BackgroundTransfusion is important in clinical treatment and red blood cells (RBC) are the mostimportant components used in blood transfusion. So, it is very important to evaluate thefunction value of RBC transfusion. The function of RBC changed during theirpreservation as “RBC storage lesion”. However, the function of RBC stored0day or35day was considered to be equal, which may influence therapy effect of blood transfusion.So, clear and definite function change of red blood cells during their preservation hasimportant guiding significance for clinical blood transfusion.ObjectiveTo measure the oxygen-carrying capacity of suspension red blood cells in thepreservation process, so as to establish mathematical model of parameter of erythrocyteoxygen-carrying evaluation with the saving time and provide experimental evidence forquantitative erythrocyte infusion.Methods 1. Explore the text condition of vitro RBC oxygen-carrying assay systems. Throughanalysis and compare the blood gas results of RBCs in different conditions,including aeration, different concentration of red blood cell samples and differentpH, to get the optimum testing conditions.2. Analysis the change of RBC during preservation： select6bags RBC and test theFHb, Na~+and K~+during their0,7,14,21,28and35days storage.3. Change of oxygen-carrying capacity of RBC in different storage time. Harvested1unit of red blood cells (200ml/unit) per person from6blood donors who meet theconditions of national blood donation, prepared into suspension red blood cells,placed in professional refrigerator. Detected effective oxygen-carrying amount (Qvalue), P50,2,3-DPG, Na~+-K~+-ATPase in the different time point of stock0days,7days,14days,21days,28days and35days to comprehensively evaluateoxygen-carrying capacity of red cells.4. Data was analyzed with SAS8.2(TS2M0) statistical software. Various indicatorsand stock time were calculated to elucidate the internal relations by curve fittinganalysis.5. Clinical practice. A couple of twins who were both Mediterranean anemia patientswere selected in out experiment. After they transfused equal volume of3d and17dRBCs which come from the same blood donor, their blood gas and routine weretested to compare the results.Results1. To determine the RBC oxygen-carrying capacity in vitro, red blood cells should bekept in a fixed oxygen partial pressure (100mmHg and40mmHg), pH valueshould be between7.0~7.1, temperature (37℃), the application of plasma insuspension medium, and set the RBC concentration as3.5×1012/L.2. Concentration of Na~+decreased during storage, but K~+increased. However, theconcentration of FHb changed few during the RBC preservation, it decreased byless than0.1%at the end of storage. 3. Q value, P50,2,3-DPG, Na~+-K~+-ATPase gradually declined with the preservationtime. At the end of preservation, Q value, P50,2,3-DPG, Na~+-K~+-ATPase retainedonly49%,71%,41%,15%compare with the blood which stocked0days.4. The various indicators of effective oxygen-carrying capacity linear correlated withstock time by curve fitting analysis. The regression equation was Y=4.367-0.066Xwith Q value as dependent variable Y, stock time as independent variable X; theregression equation was Y=28.346-0.234X with P50as dependent variable Y, stocktime as independent variable X; the regression equation was Y=1.875-0.030X with2,3-DPG as dependent variable Y, stock time as independent variable X; theregression equation was Y=4.534-0.127X with Na~+-K~+-ATPase as dependentvariable Y, inventory time as independent variable X5. Q value and P50had completely linear correlation（r=0.99943）6. The regression correlation existed in Q value,2,3-DPG, stock time, Na~+-K~+-ATPaseenzyme, the equation was Q=5.457-0.9252,3-DPG+0.142×Na~+-K~+-ATPase-0.076×T (stock days).7. Compared the patient transfused RBC stored for17days, it is a different inconcentration of Hb, RBC, PO2and SO2in patient transfused RBC stored for3days.Conclusion1. Q value in vitro could be described and evaluated as an important indicator of thestock erythrocyte oxygen-carrying capacity that can be calculated according to Qvalue change.2. Erythrocyte oxygen-carrying capacity reduced with the stock time extension. Itdramatically declined before2weeks preservation. It decreased by50%at the endof preservation compared with the beginning of preservation.