Influence of transfusion technique on survival of autologous red blood cells in the dog

Objective - To determine the effect of 3 differing transfusion techniques on survival of autologous canine RBCs. Design - Prospective, blinded study. Setting - University Teaching Hospital. Animals - Nine healthy dogs. Interventions - Three distinct preparations of RBCs, each representing ∼1% of red cell mass, were generated for each dog by biotinylation of RBCs at varying biotin densities. Labeled cells were transfused using 3 techniques (gravity, volumetric pump, syringe pump). Serial determinations of red cell survival were carried out by flow-cytometric analysis of RBCs collected at 7-day intervals for 49 days. In vitro analysis of the effect of transfusion methods on RBC integrity and osmotic fragility were carried out in 7/9 dogs. Measurements and Main Results - RBCs administered via volumetric and syringe pumps exhibited a marked decrease in short-term probability of survival compared with RBCs delivered by gravity flow. At 24 hours, only 4/8 and 1/7 dogs had surviving cell populations delivered by volumetric and syringe pump, respectively, compared with 8/8 dogs which had surviving cell populations delivered by gravity flow. Circulating half-life of cells surviving at 24 hours after delivery by volumetric pump was not significantly different to that delivered by gravity flow. No significant effect on in vitro RBC integrity or osmotic fragility was detected in relation to transfusion technique. Conclusions - Delivery of autologous canine RBCs via mechanical delivery systems was associated with a high risk for early loss of transfused cells.