Effect of compound electrolyte injection on phosphatidylserine exposure in erythrocytes after blood salvage-retransfusion in dogs

Objective To evaluate the effect of compound electrolyte injection on phosphatidylserine (PS) exposure in erythrocytes after blood salvage-retransfusion in dogs. Methods Twenty healthy mongrel dogs, weighing 10-15 kg, aged 3-5 weeks, were divided into 2 groups (n=10 each) using a random number table method: normal saline group (group NS) and compound electrolyte injection group (group MEI). The process of intraoperative blood salvage-retransfusion was simulated in both groups: femoral vein was cannulated for blood withdrawal until the volume of blood lost was 400 ml, and the shed blood was salvaged by a blood recovery machine.The washing solution was normal saline in group NS and compound electrolyte injection in group MEI.The erythrocytes were retransfused after being labeled with fluorescein isothiocyanate.Blood samples were obtained before and after blood salvage for determination of erythrocyte ATP content by enzyme-linked immunosorbent assay.Blood samples were obtained at 24, 48 and 72 h after blood retransfusion, and the PS exposure rate of the salvaged erythrocytes was determined by flow cytometry.The spleen was taken at 72 h after retransfusion to detect the phagocytosis rate of salvaged erythrocytes by monocytes. Results There was no significant difference in ATP content before and after blood salvage between the two groups (P>0.05). Compared with NS group, the PS exposure rate of the salvaged erythrocytes at each time point after retransfusion and phagocytosis rate of salvaged erythrocytes by monocytes were significantly decreased in MEI group (P<0.05). Conclusion Compound electrolyte injection as a washing solution for intraoperative blood salvage can reduce the PS exposure in salvaged erythrocytes and is helpful in prolonging the lifespan of erythrocytes after retransfusion in dogs. Key words: Electrolytes; Erythrocytes; Operative blood salvage; Phosphatidylserines; Monocytes